Welcome to your 1. 🧠 Pituitary, Growth & Water Balance Disorders Arena — 40 Integrated MCQs
1.
A 45-year-old man with long-standing acromegaly complains of nocturnal numbness and tingling involving the thumb, index and middle fingers. Which change most directly explains this complication?
2.
A patient has undergone resection of a large pituitary macroadenoma. Which combination represents the most appropriate early postoperative monitoring priorities?
3.
A patient receiving a drug that produces both antidiuresis and vasoconstriction shows increased peripheral vascular resistance. Which receptor is most directly responsible for the vascular response?
4.
A 19-year-old patient with excessive nocturnal urine production is prescribed desmopressin. The therapeutic effect depends on which change in collecting-duct principal cells?
5.
A 30-year-old woman presents with menstrual irregularity and galactorrhea. Serum prolactin is moderately elevated. Thyroid testing shows low free thyroxine with markedly elevated TSH, and pituitary MRI shows no adenoma. Which mechanism most likely explains the raised prolactin?
6.
A patient with central diabetes insipidus receives desmopressin rather than natural vasopressin for long-term antidiuretic therapy. Which pharmacodynamic property most strongly supports this choice?
7.
A 40-year-old man treated with lithium develops persistent polyuria and dilute urine. The drug cannot be immediately discontinued. Which treatment most directly targets the mechanism responsible for this acquired concentrating defect?
8.
A patient with suspected diabetes insipidus undergoes supervised water deprivation. Unlike a healthy person, the urine fails to become concentrated. Which normal physiological sequence should water deprivation have triggered?
9.
During discussion of growth-hormone replacement, a student learns that hormone obtained from human cadaveric pituitaries is no longer used. Which complication led to abandonment of this source?
10.
A 55-year-old man has polyuria, polydipsia and nocturia. Plasma osmolality is increased while urine remains inappropriately dilute. Which physiological step is failing most directly?
11.
A woman with a prolactinoma begins bromocriptine therapy. Shortly afterward she develops nausea, dizziness and light-headedness when standing from a sitting position. Which adverse effect best explains her symptoms?
12.
A 44-year-old patient with a large pituitary lesion complains of fatigue and cold intolerance. Which thyroid-function pattern most strongly supports central hypothyroidism due to pituitary failure?
13.
A 12-year-old child with confirmed growth-hormone deficiency is receiving recombinant growth hormone. Several weeks later, the child develops persistent headache, vomiting and papilledema. Which treatment-related complication should be suspected?
14.
Parents of a short but otherwise healthy child request immediate growth-hormone treatment because several classmates are taller. Which response best reflects appropriate management and communication?
15.
Five days after pituitary adenoma surgery, a patient develops headache, confusion and nausea. Serum sodium is 123 mmol/L. Which postoperative disturbance should be considered?
16.
A 28-year-old man has reduced libido and infertility. Serum prolactin is markedly elevated, and MRI demonstrates a prolactin-secreting pituitary macroadenoma. Which treatment is most appropriate as initial therapy?
17.
A 46-year-old woman has polyuria and polydipsia. During supervised water deprivation, her urine remains dilute. After desmopressin administration, urine osmolality shows little meaningful increase. Which abnormality is most consistent with this response?
18.
A 10-year-old girl is being assessed for short stature. Her father is 176 cm tall and her mother is 160 cm tall. Using the standard mid-parental height estimate, what is her approximate target height?
19.
A patient with nephrogenic diabetes insipidus is prescribed a thiazide diuretic. His urine output decreases despite receiving a drug class normally associated with diuresis. Which mechanism best explains this apparently paradoxical effect?
20.
A 39-year-old woman presents with palpitations, tremor and weight loss. Free thyroxine is elevated, but serum TSH is also inappropriately elevated. MRI demonstrates a pituitary adenoma. Which functional adenoma best explains these findings?
21.
Two days after pituitary surgery, a patient develops persistent clear watery discharge from the nose that increases when leaning forward. Which postoperative complication is most likely?
22.
A 47-year-old man has progressive enlargement of his hands, coarse facial features and elevated age-adjusted serum IGF-1. During an oral glucose suppression test, which finding would support the suspected pituitary disorder?
23.
During microscopic examination of the pituitary, a student identifies neural tissue containing unmyelinated axons terminating near capillaries. The hormones released from these axon terminals are synthesized primarily in which location?
24.
Two children are being assessed for poor linear growth. One has relatively preserved weight, while the other has both poor height gain and poor weight gain. Which finding more strongly favors chronic systemic disease rather than isolated growth-hormone deficiency?
25.
A 52-year-old woman with untreated acromegaly develops persistent hyperglycemia despite having no previous history of diabetes. Which effect of growth hormone best explains this metabolic complication?
26.
A patient with central diabetes insipidus cannot obtain water for several hours because of impaired access after an acute illness. Which change is most likely to develop if urinary losses continue?
27.
A 32-year-old man develops intense thirst and passage of large volumes of urine after surgery near the pituitary stalk. Serum sodium is elevated and urine remains dilute despite dehydration. Which defect best explains these findings?
28.
Histological examination of a pituitary tumor shows relatively uniform endocrine cells arranged in sheets. The pathologist wishes to determine the functional lineage of the tumor cells. Which investigation is most useful for this purpose?
29.
A patient with nephrogenic diabetes insipidus is considered for indomethacin therapy. Which effect explains why this drug can reduce urine volume?
30.
A patient with SIADH has dilutional hyponatremia but no prominent peripheral edema. Which physiological response best explains the absence of marked edema despite water retention?
31.
A 14-year-old boy is short compared with classmates but otherwise healthy. His skeletal maturation is delayed, puberty has not yet started, and his father reports that he also entered puberty late. Which diagnosis best fits this pattern?
32.
A patient with suspected SIADH has low plasma osmolality. Which renal response would be expected in normal physiology but is inappropriately prevented in this disorder?
33.
A patient with mild hemophilia A receives desmopressin for a bleeding-related indication. Which additional pharmacological effect of this drug explains its usefulness outside diabetes insipidus?
34.
A patient with nephrogenic diabetes insipidus is found to have significant hypercalcemia. Which management principle best addresses the cause of the concentrating defect?
35.
A hospitalized patient develops low serum sodium after severe nausea and pain. Plasma osmolality is reduced, yet urine remains concentrated. Which explanation best accounts for this pattern?
36.
A 28-year-old woman receiving desmopressin for central diabetes insipidus develops headache, nausea and increasing confusion after markedly increasing her fluid intake. Which complication should be suspected first?
37.
A 34-year-old woman has central obesity, facial rounding, proximal muscle weakness and hypertension. Serum cortisol is elevated, ACTH is not suppressed, and MRI demonstrates a small anterior pituitary lesion. Which pituitary cell type is most likely involved?
38.
A 68-year-old patient develops hyponatremia after a central nervous system illness. Plasma osmolality is low, but the urine remains relatively concentrated. Which mechanism best links these findings?
39.
A patient with central diabetes insipidus is started on desmopressin. His urine volume decreases substantially and urine becomes more concentrated. Which intracellular pathway most directly mediates this therapeutic effect?
40.
A patient with nephrogenic diabetes insipidus has persistent polyuria despite adequate endogenous vasopressin secretion. Which therapeutic strategy is most logically appropriate?
