A 45-year-old woman with long-standing acromegaly undergoes transsphenoidal resection of a pituitary adenoma. Histology shows a densely granulated adenoma with perivascular deposits of eosinophilic hyaline material demonstrated on Congo red staining. These deposits are composed of:
- A Prolactin
- B Growth hormone ✓
- C ACTH
- D Alpha-fetoprotein
Correct answer: B. Growth hormone
Explanation
Densely granulated somatotroph adenomas in acromegaly characteristically show paranuclear eosinophilic globules (fibrous bodies) that are positive for growth hormone on IHC and stain with Congo red due to their amyloid-like nature. These represent secretory granules and are a hallmark of this tumor subtype, distinguishing it from sparsely granulated somatotroph adenomas.
Reference: WHO Classification of Tumours: Endocrine and Neuroendocrine Tumours, 5th series, 2022 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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