A 52-year-old man presents with polyuria, polydipsia and an unintentional 7-kg weight loss over two months. Random plasma glucose is 390 mg/dL and HbA1c is 11.8%. He is clinically stable and has no significant ketoacidosis. Which initial therapeutic approach is most appropriate?

A 64-year-old woman presents with increasing abdominal distension, early satiety and pelvic discomfort. Examination reveals ascites. Ultrasound shows complex bilateral adnexal masses, and serum CA-125 is elevated. Which diagnosis is most consistent with this presentation?

A 22-year-old woman at approximately 12 weeks of gestation presents with excessive vomiting, vaginal bleeding and a uterus larger than expected for dates. Serum β-hCG is markedly elevated, and ultrasonography demonstrates diffuse echogenic intrauterine material without a fetus. She also has tachycardia, tremor and suppressed serum TSH. Which mechanism best explains the thyroid abnormalities?

A 25-year-old woman presents with vulval irritation and profuse yellow-green vaginal discharge. Examination shows punctate erythematous areas on the cervix, and microscopy demonstrates motile flagellated organisms. Her regular male partner is asymptomatic. Which treatment strategy is most appropriate?

A 45-year-old woman has repeated early-morning episodes of sweating, tremor and confusion that resolve after eating. During a supervised episode, plasma glucose is 39 mg/dL while insulin and C-peptide concentrations are both inappropriately elevated. A sulfonylurea screen is negative. Which diagnosis is most likely?

A 38-year-old woman presents with progressive headache, amenorrhea and difficulty seeing objects at the sides of her visual field. MRI shows a 2.4-cm pituitary macroadenoma compressing the optic chiasm and pituitary stalk. Serum prolactin is 68 ng/mL, while the remaining pituitary hormonal profile suggests a nonfunctioning adenoma. What is the most likely explanation for the raised prolactin level?

A 42-year-old woman has episodic headache, palpitations and sweating associated with severe paroxysmal hypertension. Plasma metanephrines are markedly elevated and an adrenal mass is identified. She is being prepared for surgical resection. Which preoperative pharmacological strategy is most appropriate?

A woman is examined for medico-legal purposes approximately 48 hours after an alleged delivery. Which combination of findings provides the strongest clinical support that a recent delivery has occurred?

A 29-year-old woman attends a primary-care clinic with repeated bruising and vague abdominal pain. Her husband insists on remaining in the consultation room and answers most questions for her. The physician suspects intimate partner violence. Which approach is most appropriate as the next step?

A 51-year-old asymptomatic woman undergoes screening mammography. The study demonstrates a cluster of fine pleomorphic microcalcifications, although no mass is palpable on clinical examination. Which pathological lesion should be particularly suspected?

A 21-year-old woman with type 1 diabetes presents with vomiting, dehydration and deep rapid breathing. Laboratory tests show glucose 470 mg/dL, arterial pH 7.12, bicarbonate 10 mmol/L and serum potassium 2.8 mmol/L. Which action should be taken before starting the insulin infusion?

Several workers in a battery-manufacturing unit develop abdominal colic, anemia and peripheral neuropathy. Workplace assessment identifies significant airborne lead exposure during processing. Which intervention represents the most effective preventive approach for the workforce?

A 38-year-old woman with persistent high-risk human papillomavirus infection undergoes cervical biopsy after an abnormal screening test. High-grade squamous intraepithelial neoplasia is identified. Which molecular event is most important in progression toward invasive cervical carcinoma?

A 29-year-old man develops marked polyuria and thirst after surgery for a suprasellar mass. Serum sodium is 151 mmol/L, serum osmolality is elevated, and urine osmolality is 110 mOsm/kg. After administration of desmopressin, urine osmolality rises to 520 mOsm/kg. Which diagnosis best explains these findings?

A 19-year-old woman is examined several hours after an alleged sexual assault. There are no visible genital injuries, and the hymenal tissue appears intact. Which medico-legal interpretation is most appropriate?

A 55-year-old man abruptly stops prednisolone after several months of treatment for an inflammatory disorder. He develops weakness, nausea and hypotension. Serum cortisol and ACTH are both low, but potassium remains within the reference range. What best explains the absence of marked hyperkalemia?

A 27-year-old woman at 8 weeks of pregnancy presents with weight loss, palpitations and tremor. Examination reveals a diffuse goitre, and thyroid-function tests confirm Graves hyperthyroidism requiring antithyroid treatment. Which drug is preferred during this stage of pregnancy?

A 32-year-old farmer presents 90 minutes after a snakebite. He has rapidly progressive swelling of the affected limb, bleeding from the gums and persistent oozing from venepuncture sites. A bedside clotting test shows failure of the blood to clot. Which treatment is most appropriate?

A 44-year-old woman develops circumoral tingling, painful hand spasms and a prolonged QT interval several hours after total thyroidectomy. Laboratory tests demonstrate marked hypocalcemia with an inappropriately low parathyroid hormone concentration. What is the most appropriate immediate treatment?

A 29-year-old woman presents with 7 weeks of amenorrhea, mild unilateral lower abdominal pain and vaginal spotting. She is hemodynamically stable. Transvaginal ultrasonography shows no intrauterine gestational sac and a 2.5-cm adnexal mass without fetal cardiac activity. Serum β-hCG is 2,300 IU/L, and liver and renal functions are normal. Which management is most appropriate?

A 44-year-old man has a BMI of 36 kg/m² and marked central adiposity. He also has hypertension, elevated triglycerides, low HDL cholesterol and impaired fasting glucose. Which abnormality most directly links his pattern of adiposity to these metabolic disturbances?

A 39-year-old woman presents with several months of fatigue, weight loss and postural dizziness. Examination shows generalized hyperpigmentation. Laboratory studies reveal hyponatremia and hyperkalemia, and morning serum cortisol is markedly reduced. Which additional hormonal pattern would most strongly support primary rather than secondary adrenal insufficiency?

A 55-year-old woman with primary hypothyroidism has been stable on levothyroxine for several years. After treatment for iron-deficiency anemia is started, she develops fatigue and her serum TSH rises. She reports taking levothyroxine and ferrous sulfate together every morning. What is the most likely explanation?

A 24-year-old primigravida attends routine antenatal care at 30 weeks. She feels well, but her blood pressure is 156/102 mmHg on repeated measurement and urine testing demonstrates proteinuria. Which action best reflects the safe-motherhood role of antenatal care?

A 36-year-old woman presents with a thyroid nodule and enlarged ipsilateral cervical lymph nodes. Fine-needle aspiration demonstrates papillary structures with characteristic nuclear clearing and nuclear grooves. Which pattern of spread is most characteristic of this malignancy?

A 45-year-old man undergoes transsphenoidal surgery for a pituitary macroadenoma. Twelve hours later, his urine output increases to 7 L/day. Serum sodium is 151 mmol/L and urine osmolality is markedly reduced. Which treatment is most appropriate for the underlying endocrine disturbance?

A 67-year-old man with small-cell lung carcinoma is brought to the emergency department with confusion followed by a generalized seizure. Serum sodium is 111 mmol/L and serum osmolality is low. Urine remains inappropriately concentrated, and renal, thyroid and adrenal function are otherwise satisfactory. Which intervention is most appropriate initially?

A 32-year-old man is evaluated in a medico-legal fertility dispute. He reports normal sexual desire, normal erections and successful vaginal intercourse. However, two properly collected semen samples demonstrate complete azoospermia. Which term most accurately describes his condition?

A 27-year-old woman has been taking a combined oral contraceptive regularly for 2 years without difficulty. She develops pulmonary tuberculosis and is started on a rifampicin-containing regimen. Two months later, she becomes pregnant despite reporting excellent pill compliance. Which mechanism most likely explains the contraceptive failure?

A 68-year-old man taking metformin for type 2 diabetes develops septic shock and acute kidney injury. He becomes tachypneic and confused. Arterial pH is 7.08 and serum lactate is 9.6 mmol/L. Which management principle is most appropriate?

A 28-year-old man is evaluated for infertility. He had severe bilateral orchitis after mumps during adolescence. Examination reveals small, firm testes. Serum testosterone is reduced and FSH is markedly elevated. His partner's fertility evaluation is normal. Which mechanism best explains his infertility?

A 61-year-old obese, nulliparous woman with type 2 diabetes presents with postmenopausal bleeding. Endometrial sampling demonstrates an endometrioid adenocarcinoma. Which pathogenic influence most likely contributed to the development of this malignancy?

A 59-year-old woman with an intact uterus has taken estrogen-only menopausal hormone therapy for several years. She now presents with postmenopausal bleeding. Endometrial biopsy demonstrates marked glandular proliferation with atypia. Which factor most directly contributed to this pathological change?

A 38-year-old woman presents with progressively heavy menstrual bleeding and pelvic pressure. Examination shows a firm, irregularly enlarged uterus. Pelvic ultrasound demonstrates several sharply circumscribed masses arising within the myometrium. Which diagnosis is most likely?

A 60-year-old man with type 2 diabetes has an HbA1c of 6.9%, blood pressure of 158/94 mmHg, elevated LDL cholesterol and a history of cigarette smoking. He asks whether further lowering his glucose alone will adequately reduce his cardiovascular risk. Which management principle is most appropriate?

A 52-year-old woman presents with disabling hot flushes, night sweats, sleep disturbance and vaginal dryness 18 months after her final menstrual period. She has an intact uterus, no previous thromboembolic disease and no history of hormone-dependent malignancy. Systemic menopausal hormone therapy is being considered. Which regimen best reduces her vasomotor symptoms while protecting the endometrium from hyperplasia?

A woman planning another pregnancy previously delivered a baby with a neural tube defect. She asks what intervention offers the most effective reduction in recurrence risk in a subsequent pregnancy. Which advice is most appropriate?

A 68-year-old man has progressive urinary hesitancy, weak stream and nocturia. Digital rectal examination reveals a symmetrically enlarged, smooth prostate, and evaluation supports benign prostatic hyperplasia. Because the gland is substantially enlarged, a drug intended to reduce its volume is prescribed. Which drug-mechanism pair is most appropriate?

A 43-year-old woman receiving long-term lithium therapy develops persistent thirst and passes 6–7 litres of urine daily. Serum sodium is mildly elevated and urine is dilute. Desmopressin produces little change in urine concentration. Lithium cannot immediately be discontinued because of psychiatric instability. Which drug is most useful for reducing her polyuria?

A sexual-assault survivor presents within a few hours of the alleged incident and agrees to forensic examination. Biological samples and clothing are collected for possible laboratory analysis. Which practice is most important for maintaining the evidentiary value of these materials?

A 56-year-old man with type 2 diabetes has persistent hypertension and an elevated urinary albumin-to-creatinine ratio on repeated testing. Serum creatinine remains within the normal range. Which treatment is most appropriate to reduce progression of diabetic renal disease?

A 3-year-old child from a food-insecure household develops generalized edema, growth failure and muscle wasting after being weaned onto a predominantly carbohydrate-based diet. Examination shows skin and hair changes, and hepatomegaly is present. Which nutritional disorder best explains this presentation?

A 24-year-old woman notices a painless breast lump that has remained approximately the same size for several months. Examination reveals a 2-cm firm, smooth, freely mobile mass. Ultrasonography shows a well-circumscribed solid lesion without suspicious features. Which diagnosis is most likely?

A 23-year-old woman develops lower abdominal pain, fever and purulent cervical discharge several weeks after unprotected intercourse. Examination shows cervical motion tenderness, and nucleic-acid testing is positive for Chlamydia trachomatis. Which pathological process most directly explains her increased future risk of infertility?

A man repeatedly experiences sexual arousal by secretly watching unsuspecting individuals while they undress. He has acted on these urges without their consent, causing significant social and legal problems. Which paraphilic behavior is described?

A 30-year-old woman at 11 weeks of gestation develops lower abdominal cramps and heavy vaginal bleeding. She reports passage of some tissue at home. Examination shows an open cervical os, and ultrasonography demonstrates retained products of conception within the uterine cavity. Which diagnosis best fits this presentation?

A district health report shows persistently low death rates, declining birth rates, increasing life expectancy and an ageing population. Overall population growth has become slow. Which stage of demographic transition best describes this population?

A 76-year-old man with type 2 diabetes is brought to the emergency department with severe dehydration, confusion and hypotension. Plasma glucose is 910 mg/dL, serum osmolality is markedly elevated and significant ketoacidosis is absent. What is the initial therapeutic priority?

A 46-year-old woman presents with a newly discovered irregular breast lump. Mammography and ultrasonography are suspicious for malignancy. A tissue diagnosis is required before definitive treatment planning. Which investigation is most appropriate for obtaining adequate histological material?

A 31-year-old woman presents with a thin grey vaginal discharge and an unpleasant odor after intercourse. Vaginal pH is 5.3. Microscopy demonstrates epithelial cells with borders obscured by adherent organisms, while there is little inflammatory response. Which change in vaginal flora most likely underlies this condition?

A 46-year-old woman with untreated hyperthyroidism develops high fever, agitation, vomiting and atrial fibrillation after emergency surgery. Thyroid storm is suspected. Which therapeutic step should be completed before administration of iodide?

A newborn girl develops vomiting, dehydration and hypotension during the second week of life. Examination shows virilization of the external genitalia. Laboratory testing demonstrates hyponatremia, hyperkalemia and increased serum 17-hydroxyprogesterone. Which enzyme defect is most likely?

A healthy term infant is delivered vaginally to a stable mother without complications. The mother wishes to breastfeed but is concerned that milk production may be inadequate during the first day. Which immediate practice most effectively supports establishment of successful breastfeeding?

A 36-year-old woman is diagnosed with medullary thyroid carcinoma. Her brother previously underwent adrenalectomy for pheochromocytoma, and her father was treated for primary hyperparathyroidism. Which inherited syndrome best accounts for this pattern?

A 49-year-old man with acromegaly remains symptomatic after transsphenoidal surgery. His insulin-like growth factor-1 remains elevated despite treatment with a long-acting somatostatin analogue. The endocrinologist selects a drug that directly prevents growth hormone from activating its peripheral receptor. Which drug has this mechanism?

A 58-year-old man with advanced chronic kidney disease develops diffuse bone pain. Laboratory testing shows low serum calcium, elevated phosphate and markedly increased parathyroid hormone. Which mechanism best explains the parathyroid abnormality?

A 40-year-old woman with Graves disease has persistent hyperthyroidism despite a previous course of antithyroid medication. She is a smoker and has active, moderately severe thyroid-associated orbitopathy. She now requires definitive treatment. Which option is most appropriate?

A 48-year-old man has resistant hypertension, hypokalemia, suppressed plasma renin activity and elevated aldosterone. Further evaluation indicates bilateral adrenal hyperplasia. Spironolactone improves his blood pressure but causes painful gynecomastia. Which alternative drug most appropriately targets the same hormonal pathway with less antiandrogen effect?

A 30-year-old nulliparous woman has worsening dysmenorrhea, deep dyspareunia and difficulty conceiving. Pelvic examination reveals tenderness and nodularity behind the uterus, and ultrasonography shows an ovarian cyst containing homogeneous low-level internal echoes. Which condition best explains the combination of symptoms and findings?

A 34-year-old woman presents with progressive proximal muscle weakness, easy bruising, hypertension and menstrual irregularity. Cortisol fails to suppress with low-dose dexamethasone. Plasma ACTH is elevated, while high-dose dexamethasone produces substantial suppression of cortisol secretion. Which underlying disorder is most likely?