KMU Past Paper Practice
Pituitary and Growth Disorders: Pathology, Clinical Evaluation, Pharmacotherapy and Surgical Management
4th Year MBBS • 20 A-type Single Best Answer MCQs
MCQ 1
A researcher is studying hypothalamic control of the anterior pituitary. A small quantity of hypothalamic releasing hormone reaches the pituitary rapidly without first entering the systemic circulation. Which vascular arrangement makes this possible?
Options:
Hypothalamic-hypophyseal portal circulation
The portal circulation delivers hypothalamic releasing and inhibitory hormones directly to the anterior pituitary, allowing effective control with very small hormone concentrations.
MCQ 2
A healthy volunteer has an experimentally induced rise in circulating IGF-1. Which physiological response would be expected through normal feedback regulation of the growth-hormone axis?
Options:
Reduced endogenous growth-hormone secretion
IGF-1 participates in negative feedback at hypothalamic and pituitary levels, reducing further GH secretion when GH activity is already sufficient.
MCQ 3
A patient has persistent excessive secretion of a single anterior pituitary hormone associated with a discrete sellar lesion. Which underlying process is the most important cause of this form of hyperpituitarism?
Options:
Functioning pituitary adenoma
Autonomous hormone production by a functioning anterior pituitary adenoma is the major cause of clinically significant hyperpituitarism.
MCQ 4
A 56-year-old man has a large pituitary tumor but no recognizable hormone-excess syndrome. Laboratory testing shows reduced function of several anterior pituitary axes. Which mechanism best explains these endocrine findings?
Options:
Compression of residual normal pituitary tissue
A large non-functioning adenoma may present with hypopituitarism because expanding tumor tissue compresses and impairs the remaining normal pituitary gland.
MCQ 5
During pathological examination of a resected pituitary lesion, the surgeon asks which gross appearance would be most compatible with a typical pituitary adenoma.
Options:
Soft well-circumscribed lesion within the sella
Pituitary adenomas are commonly soft, relatively well-defined sellar lesions; larger tumors may expand beyond the confines of the sella.
MCQ 6
A 50-year-old man with longstanding GH excess has loud snoring, witnessed pauses in breathing during sleep and daytime somnolence. Which effect of his endocrine disorder most directly contributes to this complication?
Options:
Upper-airway soft-tissue enlargement
GH and IGF-1 cause soft-tissue overgrowth, including tissues of the upper airway, which predisposes patients with acromegaly to obstructive sleep apnea.
MCQ 7
A patient with poorly controlled acromegaly develops exertional breathlessness. Echocardiography shows myocardial enlargement with impaired cardiac function. Which complication of chronic GH excess is most likely present?
Options:
Acromegalic cardiomyopathy
Persistent GH and IGF-1 excess can produce myocardial hypertrophy and cardiomyopathy, an important cardiovascular complication of untreated acromegaly.
MCQ 8
A patient with a GH-secreting pituitary adenoma has persistent disease despite surgery and appropriate medical therapy. Radiotherapy is being considered. Which long-term endocrine complication should be discussed before treatment?
Options:
Development of hypopituitarism
Pituitary radiotherapy may gradually damage normal hormone-producing tissue, so delayed hypopituitarism is an important long-term complication.
MCQ 9
A patient with acromegaly is started on immediate-release octreotide while the clinical response is assessed. Which regimen is consistent with an appropriate starting approach described for this drug?
Options:
50 micrograms subcutaneously three times daily
Immediate-release octreotide can be initiated at about 50 micrograms subcutaneously three times daily and adjusted according to biochemical and clinical response.
MCQ 10
A patient with acromegaly responds to short-acting octreotide and is changed to a long-acting formulation for maintenance treatment. Which administration pattern is most appropriate?
Options:
Deep intramuscular administration about every four weeks
Long-acting octreotide preparations provide sustained somatostatin-receptor stimulation and are commonly administered by deep intramuscular injection at roughly four-week intervals.
MCQ 11
A patient treated with octreotide for GH excess develops unexpected fluctuations in blood glucose despite stable diet and activity. Which known pharmacological effect best explains this finding?
Options:
Alteration of normal glucose-regulating hormone secretion
Somatostatin analogues can alter pancreatic and endocrine hormone secretion, so abnormalities of glucose regulation may occur during octreotide treatment.
MCQ 12
A child with confirmed GH deficiency requires replacement therapy. The parents ask why recombinant growth hormone cannot simply be given as a tablet. Which explanation is most appropriate?
Options:
It is a peptide that is degraded in the gastrointestinal tract
Growth hormone is a peptide and would be digested in the gastrointestinal tract, so effective replacement requires parenteral administration, commonly subcutaneous injection.
MCQ 13
A 13-year-old boy receiving recombinant GH develops a new limp and pain around the hip and knee. Examination shows reduced internal rotation of the affected hip. Which treatment-associated complication should be considered?
Options:
Slipped upper femoral epiphysis
Slipped upper femoral epiphysis is an important musculoskeletal adverse effect to consider in a growing child receiving GH who develops hip or referred knee pain.
MCQ 14
A patient with acromegaly requires additional medical treatment. The endocrinologist explains that one drug more commonly associated with prolactinoma can also reduce GH secretion in selected patients. Which drug is being described?
Options:
Bromocriptine
Bromocriptine is primarily a dopamine agonist used for hyperprolactinemia, but it can also suppress GH secretion in selected patients with acromegaly.
MCQ 15
A woman with previous destructive pituitary disease later delivers a healthy infant but is unable to produce breast milk despite normal breast development and appropriate infant suckling. Deficiency of which pituitary hormone best explains this finding?
Options:
Prolactin
Prolactin from anterior pituitary lactotrophs is required for milk production; loss of prolactin secretion can therefore cause failure of lactation.
MCQ 16
A patient with pituitary failure develops secondary adrenal insufficiency. He has fatigue, weakness and low cortisol but no generalized skin hyperpigmentation. Which feature of pituitary disease explains the absence of pigmentation?
Options:
Reduced circulating ACTH concentration
In secondary adrenal insufficiency ACTH is deficient, so the melanocortin-related stimulation responsible for hyperpigmentation in primary adrenal failure is absent.
MCQ 17
A woman suffers severe postpartum hemorrhage and later develops multiple anterior pituitary hormone deficiencies. Which normal pregnancy-related pituitary change increases vulnerability to ischemic injury in this setting?
Options:
Enlargement of the anterior pituitary from lactotroph expansion
Pregnancy enlarges the anterior pituitary, particularly through lactotroph expansion, increasing its metabolic requirements and vulnerability to severe postpartum hypoperfusion.
MCQ 18
An 8-year-old child is referred for short stature. Examination shows that the limbs are disproportionately short in relation to the trunk. Which category of growth disorder should be considered most strongly?
Options:
Underlying skeletal disorder
Disproportionate short stature suggests abnormal skeletal growth and should prompt assessment for a skeletal disorder rather than assuming an isolated endocrine cause.
MCQ 19
A 9-year-old child has poor linear growth and biochemical evidence suggesting a central growth-hormone deficiency. Additional findings raise concern for a structural hypothalamic-pituitary lesion. Which investigation best evaluates this possibility?
Options:
Pituitary magnetic resonance imaging
Pituitary MRI provides anatomical assessment of the hypothalamic-pituitary region when a structural central cause of growth-hormone deficiency is suspected.
MCQ 20
A large pituitary macroadenoma extends beyond the sella, and complete removal would risk damage to important adjacent structures. Which surgical objective is most appropriate in this situation?
Options:
Debulk the tumor and decompress critical structures safely
For an invasive macroadenoma, safe decompression and tumor debulking may be more appropriate than hazardous complete excision, while preserving normal pituitary and nearby structures.