SBA — Single Best Answer · Review
Question 499
Endocrinology → General
Classification
Question
SSBAQuestion Header
A woman with oligomenorrhoea and galactorrhoea has a persistently raised serum prolactin concentration. MRI demonstrates a pituitary lesion measuring 12 mm in maximum diameter. How should this lesion be classified?
Question Stem
Select the single best answer.
Options
A
Physiological pituitary enlargement
B
Microprolactinoma
C
Hypothalamic adenoma
D
Macroprolactinoma
E
Posterior pituitary adenoma
Explanation
A prolactinoma measuring more than 10 mm is classified as a macroprolactinoma, whereas a lesion smaller than 10 mm is a microprolactinoma. Prolactinomas may present with menstrual disturbance, galactorrhoea, hypogonadism and subfertility; larger lesions may produce visual-field disturbance.
Option Validity
A) A discrete 12 mm prolactin-secreting lesion is not classified as physiological pituitary enlargement.
B) A microprolactinoma measures less than 10 mm.
C) The lesion described is a pituitary prolactinoma rather than a hypothalamic adenoma.
E) Prolactin is produced by cells of the anterior pituitary, not the posterior pituitary.
Further Reading
Saxena, MRCOG-1 Basic Sciences, Endocrinology: Prolactin, pp. 305–306.