A pituitary adenoma causing acromegaly secretes excess growth hormone. Which type of pituitary cell (by immunohistochemistry) produces growth hormone?

• A Corticotroph (ACTH-producing, PAS-positive)
• B Gonadotroph (FSH/LH-producing, basophil)
• C Thyrotroph (TSH-producing)
• D Somatotroph (GH-producing, acidophil) ✓

Explanation

Somatotroph adenomas (acidophilic cells staining with eosin) produce growth hormone and are the second most common functioning pituitary adenoma after prolactinoma. They cause gigantism in children (open epiphyses) and acromegaly in adults. GH-secreting adenomas often harbor GNAS mutations (activating Gs-alpha mutations). Corticotrophs cause Cushing's disease; gonadotrophs may cause hypogonadism.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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