Chemical path. II sem 2 — Past Paper Questions & Answers

Question 1

A 27-year-old boy has delayed puberty and anosmia. LH and FSH are low with low testosterone. The most likely diagnosis is:

Accepted Answer

Klinefelter syndrome — Kallmann syndrome is characterized by hypogonadotropic hypogonadism and anosmia, which fits the clinical picture.

Question 2

A patient develops polyuria and polydipsia after head trauma. Urine osmolality is low and rises after desmopressin. The most likely diagnosis is:

Accepted Answer

Nephrogenic diabetes insipidus — Polyuria, polydipsia, low urine osmolality, and a rise in osmolality after desmopressin indicate central diabetes insipidus, where the pituitary fails to produce ADH.

Question 3

A 45-year-old man with a suprasellar mass has headaches and bitemporal hemianopia. The lesion most likely arises from:

Accepted Answer

Rathke pouch remnants — A suprasellar mass causing bitemporal hemianopia is characteristic of a craniopharyngioma, which arises from Rathke's pouch remnants.

Question 4

A 28-year-old woman presents with amenorrhoea and galactorrhoea. Prolactin is markedly raised. The most likely cause is:

Accepted Answer

Prolactinoma — Amenorrhoea, galactorrhoea, and markedly raised prolactin are classic symptoms of a prolactinoma.

Question 5

A pituitary macroadenoma compressing the optic chiasm most commonly causes:

Accepted Answer

Unilateral blindness — Compression of the optic chiasm by a pituitary macroadenoma typically leads to bitemporal hemianopia.

Question 6

A 52-year-old man has enlarged hands, prognathism, and sweating. IGF-1 is elevated. The most common cause is:

Accepted Answer

Ectopic GHRH secretion — The symptoms of enlarged hands, prognathism, sweating, and elevated IGF-1 are characteristic of acromegaly, most commonly caused by a pituitary somatotroph adenoma.

Question 7

A 24-year-old woman has weight loss, tremor, palpitations, and exophthalmos. TSH is suppressed and free T4 is elevated. Most likely diagnosis:

Accepted Answer

Hashimoto thyroiditis — Weight loss, tremor, palpitations, exophthalmos, suppressed TSH, and elevated free T4 are classic signs of hyperthyroidism, specifically Graves' disease due to the exophthalmos.

Question 8

Graves disease is driven primarily by antibodies to the:

Accepted Answer

Thyroglobulin — Graves' disease is an autoimmune condition caused by stimulating antibodies directed against the TSH receptor.

Question 9

A 46-year-old woman has a painless goitre and hypothyroid symptoms. Anti-TPO antibodies are positive. Most likely diagnosis:

Accepted Answer

Graves disease — A painless goitre, hypothyroid symptoms, and positive anti-TPO antibodies are characteristic features of Hashimoto's thyroiditis.

Question 10

A 40-year-old woman has hypertension and hypokalaemia with low renin. The most likely diagnosis is:

Accepted Answer

Addison disease — Hypertension, hypokalaemia, and low renin are the classic triad for primary hyperaldosteronism, also known as Conn's syndrome.

Question 11

Conn syndrome results from excess:

Accepted Answer

Cortisol — Conn's syndrome is primary hyperaldosteronism, meaning it is caused by excessive production of aldosterone.

Question 12

A 38-year-old has episodic headaches, sweating, palpitations and severe hypertension. The best screening test is:

Accepted Answer

Serum cortisol — The symptoms of episodic headaches, sweating, palpitations, and severe hypertension are highly suggestive of a pheochromocytoma, for which plasma free metanephrines or 24-hour urinary fractionated metanephrines are the best screening tests.

Question 13

A 19-year-old with abdominal pain, Kussmaul breathing, high ketones and metabolic acidosis most likely has:

Accepted Answer

Hyperosmolar hyperglycaemic state — Abdominal pain, Kussmaul breathing, high ketones, and metabolic acidosis are the hallmark features of diabetic ketoacidosis (DKA).

Question 14

Hyperosmolar hyperglycaemic state is most associated with:

Accepted Answer

Type 1 diabetes — Hyperosmolar hyperglycaemic state (HHS) is a severe complication predominantly seen in patients with Type 2 diabetes.

Question 15

A patient has recurrent fasting hypoglycaemia relieved by glucose. During symptoms, insulin is inappropriately high. Most likely tumour:

Accepted Answer

Glucagonoma — Recurrent fasting hypoglycaemia with inappropriately high insulin levels that is relieved by glucose is the classic presentation of an insulinoma.

Question 16

A 65-year-old heavy smoker presents with hyponatraemia, low plasma osmolality and concentrated urine. The most likely cause is:

Accepted Answer

Diabetes insipidus — Hyponatraemia, low plasma osmolality, and concentrated urine are characteristic of SIADH (Syndrome of Inappropriate ADH secretion), which in a heavy smoker is often caused by ectopic ADH secretion from small cell lung carcinoma.

Question 17

Ectopic ACTH secretion is most commonly associated with:

Accepted Answer

Thyroid carcinoma — Ectopic ACTH secretion, leading to Cushing's syndrome, is most frequently caused by small cell carcinoma of the bronchus (small cell lung cancer).

Question 18

Elevated urinary 5-HIAA is most indicative of:

Accepted Answer

Carcinoid syndrome — 5-HIAA (5-hydroxyindoleacetic acid) is the main metabolite of serotonin, which is produced in excess by carcinoid tumors.

Question 19

MEN1 most commonly involves tumours of:

Accepted Answer

Thyroid, adrenal, pancreas — MEN1 (Multiple Endocrine Neoplasia type 1) is classically associated with tumors of the parathyroid, pituitary, and pancreas (the 3 Ps).

Question 20

MEN2 is associated with mutation of the:

Accepted Answer

RET proto-oncogene — MEN2 (Multiple Endocrine Neoplasia type 2) syndromes are caused by germline mutations in the RET proto-oncogene.

Question 21

Hyperparathyroidism in MEN1 typically results in:

Accepted Answer

Hypocalcaemia — Hyperparathyroidism causes excessive parathyroid hormone secretion, leading to elevated serum calcium (hypercalcaemia).

Question 22

Klinefelter syndrome typically shows:

Accepted Answer

XX karyotype — Klinefelter syndrome is a genetic condition in males characterized by the presence of an extra X chromosome, resulting in an XXY karyotype.

Question 23

Clitoromegaly is most characteristic of:

Accepted Answer

Virilisation — Clitoromegaly is a prominent sign of virilisation, indicating excessive androgen exposure in females.

Question 24

Infertility is defined as failure to conceive after:

Accepted Answer

12 months — Infertility is typically defined as the inability to conceive after 12 months of regular unprotected intercourse.

Question 25

Elevated FSH in a woman with infertility suggests:

Accepted Answer

Ovarian failure — Elevated FSH levels in an infertile woman suggest ovarian failure, as the pituitary gland increases FSH production to stimulate non-responsive ovaries.

Question 26

Progesterone 30 nmol/L seven days before menses indicates:

Accepted Answer

Ovulation occurred — A progesterone level above 30 nmol/L in the mid-luteal phase confirms that ovulation has occurred.

Question 27

A 40-year-old man with severe flank pain and haematuria is most likely suffering from:

Accepted Answer

Renal calculi — Severe flank pain (renal colic) and haematuria are classic symptoms of renal calculi (kidney stones).

Question 28

A patient with nephrotic syndrome is most likely to have which of the following?

Accepted Answer

Proteinuria >3.5 g/day — Nephrotic syndrome is defined by massive proteinuria, specifically greater than 3.5 g/day.

Question 29

A "peak" sample is taken:

Accepted Answer

Before dose — A "peak" sample for therapeutic drug monitoring is taken when the drug concentration is expected to be at its maximum after administration.

Question 30

In hypoalbuminaemia, total phenytoin may be:

Accepted Answer

Falsely low relative to free level — Phenytoin is highly protein-bound; in hypoalbuminemia, less drug is bound, leading to a higher free fraction, so the measured total phenytoin level may appear falsely low relative to the pharmacologically active free level.

Chemical path. II sem 2 — Past Paper Questions & Answers

Questions, Answers & Explanations