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USMLE Step 2 (Fach) / Endocrinology (Lektion)

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• Metabolic syndrome Three out of five of the following criteria must be met:- Abdominal obesity: ≥ 102 cm in men and ≥ 88 cm in women- Triglycerides ≥ 150 mg/dL- HDL < 40 mg/dL in men and < 50 mg/dL in women- BP ≥ 130/85 mmHg- Fasting glucose ≥ 100 mg/dL Treatment:- First-line: lifestyle modifications→ Dietary changes: calorie restriction, healthy foods (e.g., fruit/vegetables, protein-rich, unsaturated fats, sodium-restricted) → Physical activity: minimum of 30 minutes moderate exercise per day (2.5 hours per week), which increases insulin sensitivity, lowers blood pressure, and promotes weight loss- Medical therapy: treat hypertension (e.g., ACE inhibitors), diabetes mellitus, and dyslipidemia (e.g., with statins) - Bariatric surgery: if BMI ≥ 40 and no success with dietary and lifestyle changes  → Sleeve gastrectomy (most common): large part of the greater curvatureis removed, so that the remaining stomach resembles a sleeve→ Roux-en-Y gastric bypass (2nd most common) 
• Comparing DKA and HHS Diabetic ketoacidosis:- Type 1 > Type 2- Precipitants: stress, infections, MI, trauma, alcohol- Abdominal pain, nausea, vomiting, Kussmaul respirations, mental status changes, and a fruity, acetone breath odor- Glucose > 250 mg/dL- Metabolic acidosis (bicarbonate < 18 mEq/L)- ↑ urine and serum ketones- ↑ anion gap- Serum osmolarity normal- Treatment: Fluids, potassium, continuous insulin, phosphorus Hyperosmolar Hyperglycemia:- Type 2- Profound dehydration, mental status changes - Glucose > 600 mg/dL- No acidosis (bicarbonate > 18 mEq/L)- Serum osmolarity > 320 mOsm/kg- Treatment: Aggressive fluids, electolyte replacement, insulin
• Testing of thyroid function TSH measurement: The single best test for the screening of thyroid disease and for the assessment of thyroid function Radioactive iodine uptake (RAI) and scan: Determines if a nodule is functioning in the case of hyperthyroidism, or nonfunctioning and requires a biopsy for malignancy workup. Free T4 measurement: The preferred screening test for thyroid hormone levels 
• Radioactive iodine findings in hyperthyroidism Graves: ↑%, diffuse uptake Multinodular goiter: ↑%, multiple nodules of increased uptake Toxic adenoma: ↑%, one area of increased uptake Thyroiditis: ↓%, low uptake, ↑ thyroglobulin Exogenous thyroid hormone: ↓%, low uptake, ↓ thyroglobulin
• Hyperthyroidism Etiology:- Hyperfunctioning thyroid gland → Graves disease (∼ 60-80% of cases) → Toxic multinodular goiter (MNG) (∼ 15-20% of cases)→ Toxic adenoma (3-5% of cases)→ TSH-producing pituitary adenoma (thyrotropic adenoma)→ Hashitoxicosis (see Hashimoto's thyroiditis)- Destruction of the thyroid gland→ Subacute granulomatous thyroiditis (de Quervain's thyroiditis)→ Post-partum thyroiditis→ Drug-induced thyroiditis (e.g., amiodarone, lithium)- Exogenous hyperthyroidism- Ectopic (extrathyroidal) hormone production (e.g. Struma ovarii, hCG-producing tumor) Clinical features:- Heat intolerance, weight loss, excessive sweating, ↑ bowel frequency, hyperreflexia- Eyes: Lid lag, Graves ophthalmopathy - Cardiovascular: Tachycardia, palpitations, hypertension- Muskuloskeletal: Fine tremor, myopathy with muscle weakness, osteopathy- Endocrinological: Oligo/amenorrhoea and anovulatory infertility; gynecomastia, decreased libido, erectile dysfunction- Neuropsychiatric: anxiety, agitation, depression, insomnia, emotional instability- Goiter: Diffuse, smooth, nontender goiter; often audible bruit at the superior poles Diagnostics:- Thyroid function tests: TSH ↓, T4 levels ↑- Serum thyroglobulin levels (Tg): if exogenous hyperthyroidism is suspected → characteristically low levels - Serum thyroid antibodies: if Graves disease/Hashimoto thyroiditis is suspected - Thyroid ultrasonography: Can diagnose the etiology of hyperthyroidism (e.g., diffuse enlargement, solitary/multiple nodules, increased vascularity of the gland)- Thyroid scintigraphy: A nuclear medicine imaging technique, which demonstrates the structure and function of thyroid tissue based on its selective uptake of radioactive iodine (RAI). Treatment:- Graves disease → antithyroid drugs, radioactive iodine ablation, or surgery- Toxic multinodular goiter and toxic adenoma → ablation or surgery- Beta-blockers offer immediate control of symptoms: Propanolol- Antithyroid drugs: Methimazole or propylthiouracil- Radioactive 131I thyroid ablation: Used in elderly patients, adverse reactions to ATDs- Subtotal thyroidectomy
• Hypothyroidism Etiology:- Primary hypothyroidism→ Hashimoto thyroiditis (autoimmune hypothyroidism)→ Thyroiditis (postpartum, postviral, subacute): follows hyperthyroid phase→ Iatrogenic (e.g., surgery, radioiodine therapy, medication)→ Nutritional (insufficient intake of iodine)- Secondary hypothyroidism: pituitary tumors → thyroid-stimulating hormone (TSH) deficiency- Congenital hypothyroidism: failure to thrive, umbilical hernias Clinical features:- Fatigue, bradykinesia, cold intolerance, dry skin, hair loss, weight gain (despite poor appetite), constipation- Myopathy, myalgia, stiffness, cramps, delayed tendon reflex relaxation, entrapment syndromes (e.g., carpal tunnel syndrome)- Myxedema: Doughy skin texture, puffy appearance, myxedema coma, hoarse voice, clumsy speech, pretibial and periorbital edema- Symptoms of hyperprolactinemia: Abnormal menstrual cycle, galactorrhea, decreased libido, erectile dysfunction- Neuropsychiatric: Impaired cognition (concentration, memory), depression Diagnosis:- TSH level, followed by free T4 and T3 levels- Antibody tests: Tg Ab (thyroglobulin) and TPO Ab (thyroid peroxidase): detectable in most patients with autoimmune hypothyroidism; TRAb (TSH receptor)- Radioactive iodine uptake test- Other lab abnormalities: ↑ LDL, ↑ triglycerides, ↑ CK, hypothermia Treatment: Levothyroxine Complications: Myxedema coma, primary thyroid lymphoma, increased cardiovascular risk
• Hyperparathyroidism Etiology:- Primary hyperparathyroidism:→ Adenoma (80% of cases)→ Hyperplasia (15-20% of cases)- Secondary hyperparathyroidism: → Chronic kidney disease (most frequent cause)→ Vitamin D deficiency Clinical features:- "Stones" – Nephrolithiasis, nephrocalcinosis- "Bones" – Bone, muscle, and joint pain; pseudogout; osteitis fibrosa cystica (cyst-like brown tumors)- "Groans" – Muscle pain, pancreatitis, peptic ulcer disease, gout, constipation- "Psychiatric overtones" – depression, fatigue, anxiety, sleep disorders- Other: Polyuria, polydipsia, shortened QT interval, weight loss Diagnosis:- Primary hyperparathyroidism: hypercalcemia, hypophosphatemia and hypercalciuria- 99mTc sestamibi scan: performed prior to surgery to determine the exact location of the abnormal glands- Skeletal x-ray: decreased bone mineral density, cortical thinning, salt-and-pepper skull Treatment: - Solitary adenoma: remove only the respective gland (parathyroidectomy)- Hyperplasia: remove all four glands (total parathyroidectomy)- Carcinoma: resection of tumor, ipsilateral thyroid lobe, and enlarged lymph node- Calcimimetics (e.g., cinacalcet) - In patients with osteoporosis: bisphosphonates- Avoid lithium and thiazide diuretics.
• Lab values in hyperparathyroidism 1°: PTH↑, Calcium ↑, PO4 ↓ 2°: PTH ↑, Calcium N/↓, PO4 (↑ when etiology is renal failure) Ectopic PTHrPa: PTH ↑, Calcium ↑, PO4 N/↑
• Acromegaly Etiology:- Pituitary GH-secreting adenoma Clinical presentation:- Large skull, coarsened features: enlarged nose, forehead, and jaw (macrognathia), widened hands, fingers, and feet- Painful arthropathy (ankles, knees, hips, spine)- Deepening of the voice, macroglossia, obstructive sleep apnea- Carpal tunnel syndrome- Hypertension (∼ 30% of cases), left ventricular hypertrophy, cardiomyopathy- Headache, vision loss (bitemporal hemianopsia), cranial nerve palsies- Glucose intolerance, diabetes Diagnosis:- Labs: ↑ IGF-1 levels - If ↑ IGF-1 → conduct oral glucose tolerance test (OGTT) with baseline GH → measure GH after 2 hours- Pituitary MRI  Treatment:- Transsphenoidal adenomectomy- Ocreotide (somatostatin anologue), pegvisomant (GH receptor antagonist) Complications:- Cardiovascular complications: the main cause of death- Diabetes mellitus- Sleep apnea- Neoplastic disease (e.g., colon cancer, thyroid cancer)
• Hyperprolactinemia Etiology:- Prolactinoma- Pituitary stalk compression- Drugs (dopamin antagonists, metoclopramide, verapamil)- Renal failure- Hypothyroidism Pathophysiology: Elevated prolactin inhibits GnRH secretion and consequently lowers LH and FSH secretion Clinical features:- Men: Hypogonadism, decreased libido, infertility, impotence, galactorrhea, gynecomastia- Women: Menstrual irregularities, oligomenorrhea or amenorrhea, anovulation and infertility, decreased libido, dyspareunia, vaginal dryness, risk of osteoporosis, galactorrhea- Bitemporal hemianopsia Diagnosis:- Serum prolactin level > 200 ng/mL- Order a pregnancy test and TSH level- MRI shows a sellar lesion Treatment:- First line: Dopamine agonists (eg, cabergoline, bromocriptine). Continue treatment for approximately 2 years before attempting cessation.- Surgery
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• Adrenal insufficiency Etiology:- Primary adrenal insufficiency→ Autoimmune adrenal cortical destruction (Addison disease)→ Congenital enzyme deficiencies→ Adrenal hemorrhage (Waterhouse-Friderichson syndrome from N. meningitidis)→ TB→ Adrenalectomy- Secondary adrenal insufficiency:→ Hypopituitarism → Cessation of long-term glucocorticoid treatment Clinical features:- Hypoaldosteronism: Hypotension- Hypocortisolism: Weight loss, anorexia, lethargy, and/or depression, intestinal complaints (nausea, vomiting, and/or diarrhea), hypotension- Hypoandrogenism: Loss of libido, loss of axillary and pubic hair- Elevated ACTH: Hyperpigmentation Diagnostics:- 8 AM plasma cortisol levels and ACTH levels- Confirmatory test: ACTH stimulation (cosyntropin) test→ Cortisol level < 3 µg/dL is diagnostic → Failure of cortisol to rise > 20 µg/dL following ACTH administration confirms diagnosis Treatment:- Primary hypoaldosteronism: Hydrocortisone + fludrocortisone- Secondary hypoaldosteronism: Only hydrocortisone (mineralocorticoid production is not ACTH dependent)
• Pheochromocytoma Etiology:- Tumor arise from chromaffin cells, which are derived from the neural crest.→  Locations include:∼ 90% adrenal medulla → ∼ 10% extra-adrenal in the sympathetic ganglia→ ∼ 10% at multiple locations→ The majority of pheochromocytomas are benign, unilateral, catecholamine-producing tumors.→ Rarely, pheochromocytomas also produce other hormones such as EPO.- 25% of pheochromocytomas are hereditary. → Multiple endocrine neoplasia type 2 (MEN 2A, MEN 2B)→ Neurofibromatosis type 1 (NF1)→ Von Hippel-Lindau (VHL) disease“10 percent rule”- roughly 10% of pheochromocytomas are: extra-adrenal, multiple, bilateral, malignant, pediatric cases, not associated with hypertension, show calcifications on imaging! Clinical features:- Episodic hypertension (or persistent hypertension in some cases)- Throbbing headache- Diaphoresis- Heart palpitations and tachycardia- Pallor- Abdominal pain and nausea- Anxiety- If EPO is secreted, signs of polycythemia Diagnosis:- Best initial test: metanephrines in plasma (high sensitivity)- Confirmatory test: metanephrines and catecholamines in 24-hour urine (high specificity)- Genetic testing: if MEN2A, MEN2B, NF1, or VHL is suspected- Adrenal/abdominal CT or MRI (after positive biochemistry tests to localize tumor) Treatment: - Surgical resection- Preoperatively, use a α-adrenergic blockade first (phenoxybenzamine) to control hypertension, followed by β-blockade to control tachycardia
• Primary hyperaldosteronism Etiology:- Bilateral idiopathic hyperplasia of the adrenal glands (most common)- Aldosterone-producing adrenal adenoma, or aldosteronoma- Familial hyperaldosteronism- Aldosterone-secreting carcinomas of the adrenal cortex- Ectopic aldosterone-producing tumors (e.g., in the kidneys or ovaries) Clinical features:- Hypertension- Features of hypokalemia: Fatigue, muscle weakness, cramping, headaches, polyuria and polydipsia, palpitations, constipation- Lack of significant edema Diagnosis:- Plasma aldosterone concentration to plasma renin activity (PAC/PRA ratio; aldosterone-to-renin ratio)→ ↑ PAC (> 15 ng/dL or 416 pmol/L) and ↓ PRA→ ↑ PAC/PRA ratio > 20- Confirmatory tests: Oral sodium loading test, saline infusion test- Adrenal CT: initial test to identify the cause of primary hyperaldosteronism already confirmed biochemically- Adrenal venous sampling: to differentiate between unilateral adenoma and bilateral hyperplasia Treatment:- Adrenal tumors: Adrenalectomy- Bilateral adrenal hyperplasia: Aldosterone receptor antagonists (epleronone, spironolactone)
• Congenital adrenal hyperplasia Pathophysiology:- Autosomal recessive defects in enzymes that are responsible for the production of cortisol.- 21β-hydroxylase (> 95% of CAH)- 11β-hydroxylase (∼ 5% of CAH)- 17α-hydroxylase (rare)- Low levels of cortisol → lack of negative feedback to the pituitary → ↑ ACTH → adrenal hyperplasia and increased synthesis of adrenal precursor steroids Clinical features:- Female infants – born with ambiguous external genitalia but normal female ovaries and uterus.- Male infants – no genital abnormalities.- Salt wasting form (more severe form of disease).→ Emesis, dehydration, hypotension, and shock – can develop in first 2 to 4 weeks of life.→ Hyponatremia and hyperkalemia – due to lack of aldosterone.→ Hypoglycemia – due to lack of cortisol. Diagnosis:- Electrolyte abnormalities include hyponatremia, hyperkalemia, and metabolic acidosis- Screening is conducted by measuring 17-hydroxyprogesterone (also for newborns) Treatment:- Immediate fluid resuscitation and salt repletion. - For all forms: lifelong glucocorticoid replacement therapy- 21β-hydroxylase deficiency: lifelong fludrocortisone therapy (aldosterone substitution)- 11β-hydroxylase deficiency: Spironolactone to block mineralocorticoid receptors- 17α-hydroxylase deficiency: Spironolactone to block mineralocorticoid receptors- Possible surgical correction of ambiguous genitalia
• Thyroid storm An acute exacerbation of hyperthyroidism, resulting in a life-threatening hypermetabolic state. Precipitating factors:- Thyroid surgery, RAI ablation, discontinuation of antithyroid medication- Acute illness (eg, trauma, infection), childbirth- Acute iodine load (eg, iodine contrast) Clinical features:- Fever as high as 40-41.1°C- Tachycardia (> 140 beats/minute), hypertension (with wide pulse pressure), atrial fibrillation, congestive heart failure- Severe nausea, vomiting, diarrhea, possibly jaundice- Severe agitation and anxiety, delirium and psychoses, seizures, coma- Goiter, lid lag, trempr & mosit skin Diagnostics:- Low/undetectable TSH, elevated free T3/T4 Treatment:- General measures: Intensive care monitoring with fluid and electrolyte substitution- Treatment of hyperthermia: ice packs, cooling blankets, and antipyretics (e.g., acetaminophen)- Beta blockers should be promptly started (propranolol)- Antithyroid drugs → First-line: propylthiouracil→ Second-line: methimazole- Potassium iodide/Lugol's iodine- Glucocorticoids: IV hydrocortisone/dexamethasone- Plasmapheresis: as a life-saving treatment, rarely needed
• Myxedema coma Etiology:- Decompensation of an existing thyroid hormone deficiency - Triggered by infections, surgery, and trauma Clinical presentation:- Cardinal symptoms: impaired mental status, hypothermia, and concurrent myxedema- Hypoventilation with hypercapnia- Hypotension (possibly shock) and bradycardia Treatment:- IV combination of T4 and T3 (possibly plus IV hydrocortisone)- Patient should be treated and monitored in an ICU
• Subacute granulomatous thyroiditis (De Quervain thyroiditis) Etiology:- Viral infections: Mumps virus, Coxsackie virus, influenza virus, echovirus, adenovirus- Mycobacterial infections Pathophysiology:1. Thyrotoxic phase (lasts 4-6 weeks)2. Hypothyroid phase (lasts 4-6 months)3. Euthyroid phase Clinical features:- Possible history of upper respiratory tract infections a few weeks prior to the onset of subacute thyroiditis- Painful, diffuse, firm goiter- Fever and/or malaise - Features of hyperthyroidism followed by features of hypothyroidism Diagnostics:- Thyroid function tests: → Thyrotoxic phase: ↑ T3 and T4 , ↑ thyroglobulin, ↓ TSH→ Hypothyroid phase: ↓ T3 and T4, ↑ TSH- Confirmatory test:→ ↑ ESR→ Radioiodine uptake study: ↓ iodine uptake (< 5%)- Histology: granulomatous inflammation, multinucleated giant cells Treatment:- Thyrotoxic phase: Consider beta-blockers to control symptoms of hyperthyroidism (i.e. palpitations and/or anxiety). - NSAIDs: pain control in the case of acute granulomatous thyroiditis- Occasionally corticosteroids (i.e. prednisolone)- Antithyroid drugs (e.g., methimazole) should not be administered. - Hypothyroid phase: levothyroxine
• Subacute lymphocytic thyroiditis Subacute lymphocytic thyroiditis is characterized by damage to follicular cells with lymphocytic infiltration resembling Hashimoto's thyroiditis instead of granuloma formation. Etiology:- Drugs: α-interferon, lithium, amiodarone, interleukin-2, tyrosine kinase inhibitors- Autoimmune disease - Postpartum thyroiditis Pathophysiology:1. Thyrotoxic phase (lasts 4-6 weeks)2. Hypothyroid phase (lasts 4-6 months)3. Euthyroid phase Clinical features:- Painless, diffuse, firm goiter - Features of hyperthyroidism followed by features of hypothyroidism Diagnostics:- Low radioactive iodine uptake – differentiates it from Graves disease during thyrotoxic phase. Treatment:- Consider beta-blockers to control symptoms of hyperthyroidism (i.e. palpitations and/or anxiety). - NSAIDs: pain control in the case of acute granulomatous thyroiditis- Occasionally corticosteroids (i.e. prednisolone)- Antithyroid drugs (e.g., methimazole) should not be administered. - Hypothyroid phase: levothyroxine
• Hashimoto's thyroiditis (Chronic lymphocytic thyroiditis) Epidemiology:- Most common form of thyroiditis and the most frequent cause of hypothyroidism in the US- Occurs particularly in women aged 30-50 years Pathophysiology:- Associations with HLA-DR3, DR4, and DR5- Associated with Non-Hodgkin's lymphoma or autoimmune diseases Clinical features:- Primarily asymptomatic- Goiter: non-tender or painless, rubbery thyroid with moderate and symmetrical enlargement- Transient hyperthyroidism (e.g., irritability, heat intolerance, diarrhea) is possible (hashitoxicosis) - Hypothyroidism (e.g., cold intolerance, constipation, fatigue) Diagnostics:- Thyroid metabolism- Antibody detection: Anti-TPO antibody positive (↑ anti-microsomal antibodies), anti-Tg antibody positive- Lipid profile: ↑ LDL and ↓ HDL- ↓ Hb - Ultrasound- Fine-needle aspiration: to exclude malignancy or lymphoma- Radioactive iodine uptake test (RIUT) Treatment:- Levothyroxine (T4) replacement therapy- Life-long monitoring of thyroid parameters (primarily TSH) is necessary to adjust treatment accordingly
• Riedel thyroiditis Rare, special form of autoimmune thyroiditis. Pathophysiology:- Invasive fibrous growth beyond the thyroid tissue into surrounding tissue with destruction of thyroid tissue Clinical presentation:- Goiter- Symptoms of compression Treatment: Surgery may be necessary because of compression
• Thyroid nodules Benign thyroid nodules (∼ 95% of cases):- Thyroid adenomas→ Follicular adenoma (most common)→ Hürthle cell adenoma→ Toxic adenoma→ Papillary adenoma (least common)- Thyroid cysts- Dominant nodules of multinodular goiters- Hashimoto's thyroiditis Malignant thyroid nodules (∼ 5% of cases)- Thyroid carcinoma- Thyroid lymphoma- Metastatic cancer from breast/renal carcinoma (rare)- Risk factors for malignancy→ Male gender→ Extremes in age (< 20 years and > 65 years)→ History of radiation to the head or neck→ Family history of thyroid cancer or polyposis→ Solid nodule → Cold nodule Diagnostics:- Initial tests: thyroid ultrasound and TSH levels → ↑ or normal TSH → consider FNA based on sonographic criteria or follow-up if criteria are not met→ ↓ TSH → thyroid scintigraphya. Hot nodule → check T3 and FT4 to assess cause of hyperthyroidismb. Cold nodule → consider either FNA (based on sonographic criteria) or monitoring (with repeat ultrasounds) if criteria are not met - Sonographic criteria for fine-needle aspiration (FNA):→ Solid nodule with suspicious appearance (e.g., oval shape, irregular border, calcifications) that are ≥ 1 cm in diameter→ Nodules ≤ 1 cm in patients with risk factors for malignancy → Large thyroid nodules (≥ 1.5-2 cm), even if they appear benign
• Euthyroid sick syndrome Occurs in severe illness or under severe physical stress (especially in intensive care patients). Pathophysiology:- Normal thyroid function- Cytokines (e.g., interleukin 6) cause various changes in levels of circulating TSH and thyroid hormones.- The most common pattern is a decrease in both total and free T3 levels; normal levels of T4 and TSH; reverse T3 (rT3) level increased (low T3 syndrome) Factors in acute illness that inhibit peripheral deiodination: High endogenous cortisol levels, inflammatory cytokines, starvation, medications (eg, glucocorticoids, amiodarone) Laboratory: - n/↓ TSH, ↓ FT3- ↑ rT3 - FT4 levels may be normal or, in prolonged courses of illness, low. Treatment: usually not recommended as thyroid function is normal; insufficient evidence that thyroid hormone substitution is beneficial to the patient
• Thyroid cancer Papillary thyroid carcinoma (∼ 80% of cases):- 30-50 years of age- Associated with RET/PTC rearrangements and BRAF mutations- Associated with childhood radiation- Well-differentiated- Lymphatic metastasis (often detected before primary tumor)- Most common type of thyroid cancer- May be multifocalFollicular thyroid carcinoma (∼ 10% of cases):- 40-60 years of age- Associated with PAX8-PPAR-γ rearrangement and RAS mutation- Hematogenous metastasis (lungs, bone)- Rarely multifocal- Tumor capsule or vascular invasion distinguishes it from a benign adenoma. A tissue sample is therefore needed for diagnosis.- Variant = Hürthle cell carcinoma – characteristic cells contain abundant cytoplasm, tightly packed mitochondria, and oval nuclei with prominent nucleoli. These tumors are radioiodine resistant. Anaplastic thyroid carcinoma (∼ 1-2% of cases):- After 60 years of age- Poorly-differentiated- Rapid local growth- Lymphatic and hematogenous metastasis Medullary carcinoma (< 10% of cases):- 50-60 years of age- Originates from parafollicular cells (C cells) – produce calcitonin- Sometimes a genetic predisposition → multiple endocrine neoplasia type 2 (MEN2) (25% of medullary carcinomas)- Sporadic (75% of medullary carcinomas) Treatment:- Total/radical thyroidectomy with neck dissection → Exception: papillary microcarcinoma < 1 cm; in which case, hemithyroidectomy is sufficient.- Radioiodine therapy: often conducted 4-6 weeks after surgery to destroy remaining thyroid tissue or metastases- Thyroid hormone therapy with L-thyroxine after thyroidectomy- If poorly differentiated: + combined chemo- and radiation therapy
• Hypopituitarism Etiology:- Intrasellar mass: Nonsecretory pituitary macroadenomas (most common)- Pituitary apoplexy→ Most commonly occurs in patients with a pre-existing pituitary adenoma→ Sheehan syndrome: postpartum necrosis of the pituitary gland→ Traumatic brain injury (especially around the skull base)- Infection- Congenital deficiency of hypothalamic hormones: GnRH deficiency (Kallman syndrome) Clinical features:- GH deficiency: dwarfism- Prolactin deficiency: lactation failure following delivery- FSH/LH deficiency: amenorrhea, infertility, loss of libido, infertility, loss of secondary sex characteristics- TSH deficiency: weight gain, cold intolerance, lethargy, constipation, dry skin - ACTH deficiency: weight loss, weakness, hypotension, chronic hyponatremia, hypoglycemia- Central diabetes insipidus: polyuria, polydipsia- Intrasellar/parasellar masses (e.g., pituitary macroadenomas, craniopharyngiomas) can present with headache, visual field defects (bitemporal hemianopsia), and/or diplopia Diagnostics:- Low levels of target hormones with low or normal levels of trophic hormones- MRI of the brain Treatment:- Transsphenoidal resection in cases of pituitary macroadenomas and hormone replacement therapy.
• Diabetes insipidus Central diabetes insipidus (most common form): - Primary (∼ ⅓ of cases): Most cases are idiopathic. - Secondary (∼ ⅔ of cases)→ Brain tumors (especially craniopharyngioma) and cerebral metastasis (most common: lung cancer and leukemia/lymphoma) → Neurosurgery: usually after the removal of large adenomas→ Traumatic brain injury, pituitary bleeding, subarachnoid hemorrhage→ Pituitary ischemia (e.g., Sheehan's syndrome) → Infection (e.g., meningitis) Nephrogenic diabetes insipidus: defective ADH receptors in the distal tubules and collecting ducts- Hereditary (very rare) - Acquired→ Adverse effect of medications (lithium, demeclocycline)→ Hypokalemia, hypercalcemia→ Renal disease (e.g., autosomal dominant polycystic kidney disease, renal amyloidosis)→ Pregnancy Clinical features:- Polyuria with dilute urine- Nocturia → Restless sleep, daytime sleepiness- Polydipsia- In cases of low water intake → severe dehydration Diagnostics:- Test sodium, plasma osmolality, and urine osmolality values - A water deprivation test then allows DI to be differentiated from primary polydipsia. - The patient's response to the administration of desmopressin, furthermore, distinguishes CDI from NDI. - If CDI is diagnosed, a CT scan or MRI of the head should be conducted to rule out brain tumors (especially craniopharyngioma). Treatment:- Central diabetes insipidus→ Desmopressin: synthetic vasopressin without vasoconstrictive effects→ Alternative medication: Chlorpropamide (Increases ADH secretion and strengthens the effect of ADH)- Nephrogenic diabetes insipidus→ Thiazide diuretics (lead to sodium depletion, which causes sodium and water reabsorption in the proximal tubules. As a result, less water reaches the distal tubules and volume of urine decreases)→ NSAIDs→ Amiloride (Indicated in patients with lithium-induced NDI; amiloride blocks lithium entry through the sodium channel)
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH) Etiology:- CNS disturbance (e.g., stroke, hemorrhage, infection, trauma)- Pulmonary disease (pneumonia, COPD)- Drugs (e.g., carbamazepine, cyclophosphamide, SSRIs, NSAIDs)- Neurosurgery (especially: transsphenoidal pituitary surgery)- Ectopic ADH secretion (eg, small cell lung carcinoma)- Pain &/or nausea Clinical features:- Symptoms of hyponatremia → Mild: anorexia, nausea, vomiting, headache, muscle cramps→ Moderate: muscle weakness, lethargy, confusion→ Severe: seizures, altered consciousness- Normotensive, euvolemic (eg, moist mucous membranes, no edema, no JVD) Diagnostics:- Blood:→ ↓ serum osmolality (< 275 mOsm/kg H2O = hypotonic) and ↓ sodium (< 135 mmol/L)→ Normal renal, adrenal, thyroid function→ Plasma ADH normal to elevated→ Frequently ↓ uric acid valuesUrine:→ Urine osmolality > 100 mOsm/kg H2O→ Urinary sodium excretion > 40 mEq/L Treatment:- Asymptomatic: Fluid restriction, increased salt intake- Symptomatic patients: Hypertonic (3%) saline administration with ICU monitoring to impede central pontine myelinolysis- If severe: consider adding a loop diuretic (e.g., furosemide) to hypertonic saline- If initial measures fail, consider ADH receptor antagonist (demeclocycline) or vasopressin antagonists (vaptans): IV conivaptan and PO tolvaptan
• Hypoparathyroidism Etiology:- Postoperative (most common cause): secondary to (para-)thyroidectomy, radical neck dissection- Autoimmune: second most common cause- Congenital: Parathyroid aplasia or hypoplasia (DiGeorge syndrome)- Infiltration of parathyroid gland (Wilson's disease, hemochromatosis, granulomas, metastases)- Radiation-induced destruction- Gram-negative sepsis Clinical features:- Symptoms of hypocalcemia → Chvostek sign: hypocalcemia → hyperexcitable nerves → tapping the facial nerve on the cheek → contraction of facial muscles→ Trousseau sign: inflate BP cuff → allow for occlusion of brachial artery for a few minutes → carpal spasm- Extrapyramidal disorders: symptoms include parkinsonism, dystonia, hemiballismus, choreoathetosis, oculogyric crises, or dementia- Ocular disease: cataracts, keratoconjunctivitis- Skeletal: increased bone mineral density, osteosclerosis- Prolonged QT interval on ECG Diagnostics:- Low serum calcium- High serum phosphate- Serum PTH inappropriately low - Low urine cAMP- Calcification of the basal ganglia Treatment: Calcium and vitamin D supplementation
• Cushing syndrome Etiology:- Exogenous Cushing's syndrome (most common cause): Hypercortisolism as a result of prolonged glucocorticoid therapy- Primary hypercortisolism (ACTH-independent Cushing's syndrome): Autonomous overproduction of cortisol by the adrenal gland → ACTH suppression→ Adrenal adenoma/carcinoma→ Macronodular adrenal hyperplasia- Secondary hypercortisolism→ Pituitary ACTH production (Cushing's disease)→ Ectopic ACTH production: Small cell lung cancer, renal cell carcinoma Clinical features:- Skin: Thin, easily bruisable skin with stretch marks (classically purple abdominal striae) and/or ecchymoses; delayed wound healing; hirsutism; acne- If secondary hypercortisolism: often hyperpigmentation- Neuropsychological: lethargy, depression, sleep disturbance, psychosis- Musculoskeletal: Osteopenia, osteoporosis, pathological fractures, avascular necrosis of the femoral head, muscle atrophy/weakness- Insulin resistance → hyperglycemia → diabetes- Weight gain characterized by central obesity, moon facies, and a buffalo hump- ♂: decreased libido- ♀: decreased libido, virilization, and/or irregular menstrual cycles- Secondary hypertension (∼ 90% of cases)- Increased susceptibility to infections- Peptic ulcer disease- Cataracts Diagnostics:1. Screening for hypercortisolism- ↑ 24-hour urine cortisol - ↑ early morning serum cortisol levels following a low-dose dexamethasone suppression test- ↑ midnight salivary/serum cortisol2. ACTH level- Low (< 5 pg/mL): suspect primary hypercortisolism (adrenal adenoma, carcinoma)- Normal or elevated (> 20 pg/mL): suspect secondary hypercortisolism3. If secondary hypercortisolism is suspected: differentiate between Cushing's disease and ectopic ACTH production- High-dose dexamethasone suppression test→ Adequate suppression of cortisol levels to less than 50% of baseline: Cushing's disease→ No suppression: ectopic ACTH production- CRH stimulation test→ ACTH and cortisol levels increase further: Cushing's disease→ No increase in ACTH or cortisol levels: ectopic ACTH production4. Imaging- If primary hypercortisolism is suspected: CT and/or MRI of the abdomen for adrenal tumors- If Cushing's disease is suspected: CT and/or MRI of the skull- If ectopic ACTH production is suspected: chest x-ray and/or CT, abdominal CT Treatment:- Exogenous Cushing's syndrome: Consider lowering the dose of glucocorticoids/use of alternatives (e.g., azathioprine)- Operable disease: surgical therapy is the treatment of choice → Adrenocortical tumor: laparoscopic or open adrenalectomy→ Pituitary adenoma: transsphenoidal resection → ACTH-secreting ectopic tumor: resection of the ectopic foci (e.g., bronchial carcinoid)- Inoperable disease: Drugs to suppress cortisol synthesis: metyrapone, ketoconazole, etomidate
• Diabetes mellitus Classification according to the WHO and American Diabetes Association (ADA):1. Type 1: Insulin-dependent (IDDM) or juvenile-onset diabetes mellitus- Autoimmune (type 1A)- Idiopathic (type 1B)2. Type 2: Non-insulin-dependent (NIDDM) or adult-onset diabetes mellitus3. Other types of diabetes mellitus- MODY (maturity onset diabetes of the young): Different forms of autosomal dominant inherited diabetes mellitus that manifest before the age of 25 years and are not associated with obesity or autoantibodies- Genetic defects in insulin function- Diseases of the exocrine pancreas (pancreoprivic diabetes mellitus) - Endocrinopathies: Cushing disease, acromegaly- Drug-induced diabetes: e.g., corticosteroids4. Gestational diabetes Etiology:Type 1: - Association with HLA-DR3 and HLA-DR4 - Association with other autoimmune conditions (e.g., Hashimoto thyroiditis, type A gastritis, celiac disease)Type 2:- Association with metabolic syndrome- Obesity, high-calorie diet- High waist-to-hip ratio (visceral fat accumulation)- Physical inactivity- First-degree relative with diabetes- Ethnicity- Hypertension- Dyslipidemia- History of gestational diabetes Clinical features:- Polyuria, polydipsia- Polyphagia- Fatigue- Visual disturbances: blurred vision- Calf cramps- Poor wound healing- Pruritus Diagnostics:- Testing recommendations:→ Screen all adults over age 45 every 3 years.→ For those with risk factors for diabetes (obesity, family history, history of gestational diabetes), start screening earlier. Some recommend early screening for African Americans and Native Americans.→ Test anyone with signs or symptoms of diabetes.- Fasting plasma glucose (FPG) ≥ 126 (≥ 7.0) mg/dL (mmol/L)- 2-hour glucose value after oral glucose tolerance test (OGTT) ≥ 200 (≥ 11.1) mg/dL (mmol/L)- Hemoglobin A1C (HbA1c) ≥ 6.5 %- Autoantibodies for diabetes mellitus type 1: Anti-glutamic acid decarboxylase antibody (Anti-GAD) - C-peptide: → ↓ C-peptide levels indicate an absolute insulin deficiency → type 1 diabetes→ ↑ C-peptide levels may indicate insulin resistance and hyperinsulinemia → type 2 diabetes- Urine analysis: Microalbuminuria, glucosuria, ketone bodies
• Diabetes mellitus – Complications Acute:- Hyperglycemic crisis: Hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA)- Life-threatening hypoglycemia: secondary to inappropriate insulin therapy Long-term:- Macrovascular disease→ Pathophysiology: The major determinants are metabolic risk factors, which include obesity, dyslipidemia, and arterial hypertension. Hyperglycemia may be less related to the development of macrovascular disease.→ Coronary heart disease (CHD)→ Cerebrovascular disease→ Peripheral artery disease (PAD)→ Mönckeberg arteriosclerosis (medial calcific sclerosis = variant of PAD)- Microvascular disease→ Onset: typically arises 5-10 years after onset of disease→ Pathophysiology: Chronic hyperglycemia is the primary factor influencing the development of microvascular disease; results in glycation of proteins and lipids with subsequent impaired protein and cell membrane function and tissue damage→ Diabetic nephropathy→ Diabetic retinopathy→ Diabetic neuropathy→ Diabetic foot- Diabetic cardiomyopathy- Diabetic fatty liver disease- Hyporeninemic hypoaldosteronism- Increased risk of infection
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• Somogyi effect Early-morning hyperglycemia because of a counterregulatory secretion of hormones that is triggered by nocturnal hypoglycemia secondary to an evening insulin injection. Treatment: reduction of the evening dose of the long-acting insulin
• Dawn phenomenon A common problem (especially in young type 1 diabetic patients). Definition: early-morning hyperglycemia occurs because of the physiological increase of growth hormone levels in the early morning hours, which stimulates hepatic gluconeogenesis. The subsequent increase in insulin demand cannot be met in insulin-dependent patients, resulting in elevated blood glucose levels in the morning. Treatment: measurement of nocturnal blood glucose levels before initiating insulin therapy. The long-acting insulin dose may be given later (around 11 p.m.) or increased under careful glycemic control. Treatment with an insulin pump may be considered in children.
• Hyperglycemic crises Etiology:- Undiagnosed, untreated diabetes mellitus- Treatment failure in known diabetics: insulin pump failure, forgotten insulin injection, noncompliance with insulin therapy- Stress: infections, surgery, trauma, myocardial infarction- Drugs: glucocorticoid therapy, cocaine use, alcohol abuse Clinical features:- Polyuria, polydipsia- Nausea and vomiting- Signs of volume depletion (i.e., dry mucous membranes, decreased skin turgor), hypotension- Neurological abnormalities: Altered mental status, lethargy, coma- Signs and symptoms specific to DKA→ Rapid onset (< 24 h) in contrast to HHS→ Abdominal pain→ Fruity odor on the breath (from exhaled acetone) → Hyperventilation: Kussmaul respirations: deep breaths at a normal respiratory rate Diagnostics:- Initial approach→ ABCs: airway, breathing, and circulation→ Mental status check→ Fingerstick glucose→ History (taken from family members or friends if need be), including possible precipitating factors- Diagnostic tests→ ↑ Serum glucose: < 600 mg/dL → DKA; > 600 mg/dL → HHS→ Urine ketones→ Serum electrolytes, including bicarbonate (with anion gap calculation) → Hypertonic hyponatremia → Arterial blood gas if serum bicarbonate is reduced → Plasma osmolality (if HHS is suspected) Treatment:- Admission to intensive care unit- Fluid replacement (and regular monitoring of volume status)→ Isotonic saline solution (0.9% sodium chloride): 1000 mL in the first hour → followed by replacement dependent upon central venous pressure (CVP) or urine output → If serum glucose falls to < 200-250mg/dL, add 5% dextrose to infusion, to avoid hypoglycemia- Insulin (and hourly serum glucose monitoring until stable): low-dose insulin therapy with IV regular insulin- Bicarbonate (and monitoring of acid-base status)- Potassium chloride should be administered at serum potassium levels ≤ 5.3 mEq/L.
• Hypoglycemia The lower limit of normal for fasting plasma glucose is 70 mg/dL (3.9 mmol/L). Etiology:- In diabetics: (relative) overdose of insulin or noninsulin drug for treating diabetes mellitus (sulfonylurea, meglitinide). This is by far the most common cause of hypoglycemia.- In non‑diabetics: possible factitious disorder: A high index of suspicion should be present in patients who have access to insulin and other diabetes medications, e.g., medical professionals.- Insulinoma- Chronic alcohol use- Beta blockers- Liver or kidney failure Clinical features:- Increased sympathetic activity: tremor, pallor, anxiety, tachycardia, sweating, and palpitations- Increased parasympathetic activity: hunger, paresthesias, nausea, and vomiting- Agitation, confusion, behavioral changes- Seizure, focal neurological signs- Somnolence → obtundation → stupor → coma Diagnostics:- Patient history: physical activity, food intake, alcohol consumption, insulin replacement therapy (units and location of injection) - Laboratory tests: ↓ Blood glucose or self-monitored blood glucose (SMBG)- Sulfonylurea level and exogenous insulin (elevated insulin with low C-peptide) Treatment:- Patient is conscious: oral glucose 15-20 g or fast-acting carbohydrates such as glucose tablets, candy, or juice - Patient is unconscious (or unable to ingest glucose): 25 g of 50% glucose IV (dextrose) and regular serum glucose monitoring. Subsequent glucose infusions or food may be needed.- If both oral and IV routes are not feasible: 0.5-1.0 mg glucagon IM or SC- If the patient is an alcoholic (or suspected alcoholic), give thiamine before administering glucose to avoid Wernicke encephalopathy.
• Multiple endocrine neoplasia MEN 1:- Genetics: Altered menin protein expression- Diseases:→ Hyperparathyroidism (∼ 90% of cases)→ Endocrine pancreatic tumors (∼ 50-80% of cases) such as gastrinoma (most common) and insulinoma→ Pituitary adenoma (∼ 30-50% of cases): most commonly prolactinoma→ Carcinoid tumors (∼ 10-15% of cases)- Management:→ Parathyroidectomy→ Excision of pancreatic tumor→ Transsphenoidal surgery for excision of pituitary adenoma MEN 2:- Genetics: Altered expression of the RET proto-oncogene → elevated tyrosine kinase activity- Diseases:→ Medullary thyroid carcinoma (95-100% of cases)→ Pheochromocytoma (∼ 40% of cases)→ MEN 2A: + Primary hyperparathyroidism (∼ 20–30% of cases)→ MEN 2B: + Multiple neurinomas (mucosal neuroma, intestinal ganglioneuromatosis); marfanoid habitus (> 95%)- Management:→ Thyroidectomy including cervical lymph nodes→ If pheochromocytoma removal (adrenalectomy)→ If hyperparathyroidism: Parathyroidectomy
• Diabetes - Diagnosis 1. Hemoglobin A1C ≥ 6.5%. 2. Fasting plasma glucose level of ≥ 126 mg/dL (7.0 mmol/L). 3. Plasma glucose ≥ 200 mg/dL (11.1 mmol/L) 2 hours after an oral glucose tolerance test. 4. In a patient with classic symptoms of hyperglycemia, a single reading of the random plasma glucose ≥ 200 mg/dL (11.1 mmol/L) will be enough to make the diagnosis.
• Management of DKA & HHS IV fluids:- High-flow 0.9% normal saline is initially recommended- Add dextrose 5% when serum glucose is ≤ 200 mg/dL Insulin:- Initial continuous IV insulin infusion- Switch to SQ (basal bolus) insulin for the following: Able to eat, glucose < 200 mg/dL, anion gap < 12 mEq/L, serum HCO3 ≥ 15 mEq/L- Overlap SQ & IV insulin by 1-2 hours Potassium:- Add IV potassium if serum K+ ≤ 5.2 mEq/L- Hold insulin for serum K+ < 3.3 Eq/L Bicarbonate: Consider for patients with pH < 6.9 Phosphate: Consider for serum phophate < 1.0 mg/dL, cardiac dysfunction, or respiratory depression
• Complications of Graves disease treatment Antithyroid drugs (thionamides):- Skin rash (most common)- Agranulocytosis- Methimazole: 1st-trimester teratogen, cholestasis- Propylthiouracil: Hepatic failure, ANCA-associated vasculitis Radioiodine ablation: - Permanent hypothyroidism- Worsening ophthalmopathy- Possible radiation side effects
• Effect of intensive glycemic control in type 2 diabetes Macrovascular complications (eg, acute myocardial infarction, stroke)- No change Microvascular complications (eg, neuropathy, retinopathy)- ↓
• Thyrotoxicosis and RAIU Thyrotoxicosis with normal or ↑ RAIU (radioactive iodine uptake):- Graves disease- Toxic multinodular goiter- Toxic nodule Thyrotoxicosis with ↓ RAIU:- Painless (silent) thyroiditis- Subacute (de Quervain) thyroiditis- Amiodarone-induced thyroiditis- Excessive dose (or surreptitious intake) or levothyroxine- Struma ovarii- Iodine-induced- Extensive thyroid cancer metastasis
• Recommended glycemic targets for adults with diabetes mellitus Preprandial/fasting glucose: 80-130 mg/dL Postprandial glucose: < 180 mg/dL Hemoglobin A1c: < 7%- Very high A1c levels (> 10%) suggest severe fasting hyperglycemia- Lesser abnormalities may be due to elevations in only postprandial glucose levels
• Clinical features of androgen abuse Types of androgens:- Exogenous (eg, testosterone replacement therapy)- Synthetic (eg, stanozolol, nandrolone)- Androgen precursors (eg, DHEA) Side effects/clinical presentation:- Reproductive→ Men: decreased testicular function & sperm production, gynecomastia→ Women: acne, hirsutism, voice deepening, menstrual irregularities- Cardiovascular: left ventricular hypertrophy, possible ↓ HDL & ↑ LDL- Psychiatric: aggressive behavior (men), mood disturbances- Hematologic: polycythemia, possible hypercoagulability
• Osteoporosis risk factors Nonmodifiable:- Advanced age- Postmenopausal- Low body weight- White or Asian ethnicity- Malabsorption disorders- Hypercortisolism, hyperthyroidism, hyperparathyroidism- Inflammatory disorders (eg, rheumatoid arthritis)- Chronic liver or renal disease Modifiable:- Smoking- Excessive alcohol intake- Sedentary lifestyle- Medications (eg, glucocorticoids, anticonvulsants)- Vitamin D deficiency, inadequate calcium intake- Estrogen deficiency (eg, premature menopause, hysterectomy/oophorectomy) Highest risk for fragility fracture is prior history of fragility fracture.
• Heat stroke Life-threatening condition in which the body temperature exceeds 41.1°C because of an imbalance in heat generation and dissipation. Whereas in fever there is a physiological increase in the temperature setpoint of the body, in a heatstroke the hypothalamus setpoint remains normal. Clinical features:- Hot skin, no sweating (due to a failure of thermoregulatory mechanisms)- Headache- Nausea, vomiting- Tachypnea, tachycardia- Tender, rigid, limp, or cramping muscles- Rhabdomyolysis- Delirium, hallucinations, loss of consciousness- Acute renal injury Treatment:- Rapid reduction of the core temperature to 39°C- Immersion in ice water
• Conditions that alter TBG concentration ↑ TBG: - Estrogens (e.g., pregnancy, OCs, HRT) & estrogenic medications (e.g., tamoxifen)- Acute hepatitis ↓ TBG:- Androgenic hormones- High-dose glucocorticoids/hypercortisolism- Hypoproteinemia (e.g., nephrotic syndrome, starvation)- Chronic liver disease
• Toxic adenoma Epidemiology:- Accounts for ∼ 5–10% of hyperthyroidism cases- ♀ > ♂- Seen mostly in patients 30–50 years of age Pathophysiology: - Gain-of-function mutations of TSH receptor gene in a single precursor cell → autonomous functioning of the follicular cells of a single nodule  → focal hyperplasia of thyroid follicular cells → toxic adenoma- The autonomous nodule overproduces thyroid hormones → hyperthyroidism → decrease in pituitary TSH secretion → suppression of hormone production from the rest of the gland  Clinical features: hyperthyroidism Diagnostics:- ↑ T3 and ↓ TSH- Thyroid scintigraphy: solitary, hot nodule→ Shows radioiodine uptake by the hyperfunctioning nodules with suppression of rest of the gland Treatment:- Control symptoms with beta-blockers and thioamides until euthyroidism is achieved, followed by tapering of beta-blockers- Definitive treatment: Radioactive iodine ablation or lobectomy or hemi-thyroidectomy for pure toxic adenomas
• Adrenal crisis Acute, severe glucocorticoid deficiency that is usually precipitated by one of the following triggers:- Stress (e.g., infection, trauma, surgery) in a patient with underlying adrenal insufficiency- Sudden discontinuation of glucocorticoids after prolonged glucocorticoid therapy- Bilateral adrenal hemorrhage or bilateral adrenal infarction (e.g., Waterhouse-Friderichsen syndrome)- Pituitary apoplexy  Clinical features:- Fever- Vomiting, diarrhea- Severe abdominal pain (which mimics peritonitis)- Impaired consciousness- Hypotension and/or shock- Hypoglycemia, hyponatremia, hyperkalemia, and metabolic acidosis Therapy:- Administration of high doses of hydrocortisone: 100 mg intravenous hydrocortisone followed by 100-200 mg hydrocortisone over 24 hours- Fluid replacement with normal saline to treat hypotension and hyponatremia- Correct hypoglycemia, hyperkalemia, and metabolic acidosis.- Intensive care monitoringAdrenal crisis can be life-threatening. Therefore, treatment with high doses of hydrocortisone should be started immediately without waiting for diagnostic confirmation of hypocortisolism!
• Short stature Short stature: height of 2 or more standard deviations below the mean for children of the same age, sex, and, ideally, race and ethnicity; or an adult height of 147 cm or less Diagnostics:- Family history- CBC, differential blood count, ESR- Thyroid function tests- Renal function tests and urinalysis- Screening for GH deficiency - Hormone profile to assess puberty status (LH, FSH, estrogen/testosterone)- Genetic karyotyping- X-ray→ Anterior posterior image of left hand and wrist→ Bone age is determined and adult height is predicted by comparing x-ray images of the hand to images of bones in a standard atlas of bone development, which is based on data from large numbers of other children of the same age and gender.
• VIPoma Neuroendocrine tumor that secretes excess VIP Pathophysiology:- Excess VIP → increases relaxation of gastric and intestinal smooth muscles and adenylate cyclase (cAMP) activity (similar to cholera toxin) → secretory diarrhea and inhibition of gastric acid production- Associated with MEN1 syndrome (5% of cases) Tumor location: The primary tumor is most frequently found in the pancreas. Clinical features:- WDHA syndrome (Watery Diarrhea, Hypokalemia, Achlorhydria)- Tea-colored watery diarrhea (> 700 mL/day) → dehydration- Weight loss- Abdominal pain, nausea, vomiting- Achlorhydria → ↓ iron and B12 absorption → anemia Diagnosis:- ↑ Serum VIP concentration (> 75 pg/mL)- Hypokalemia, hypercalcemia, hyperglycemia- Gastric achlorhydria or hypochlorhydria - CT scan to localize the primary tumor Treatment: tumor resection or octreotide
• Functional adrenal masses Cortisol-producing adenoma:- Central obesity, moon facies, enlarged dorsocervical fat pad- Hypertension- Proximal muscle weakness- Hyperglycemia, hypokalemia→ Elevated cortisol (urine, salivary)→ Decrased ACTH & DHEAS→ No suppression by dexamethasone Aldosterone-producing adenoma- Hypertension- Hypokalemia (muscle cramps, weakness)→ Elevated plasma aldosterone-to-plasma renin activity ratio Pheochromocytoma:- Paroxysmal tachycardia, headache, tremor- Hypertension→ Elevated urine metanephrines & catecholamines→ Elevated plasma metanephrines

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