Per the WHO 2022 classification of pituitary neuroendocrine tumors, lineage-specific transcription factors are used to subtype adenomas. A sparsely granulated somatotroph tumor showing keratin 8/18 (CAM5.2) positive fibrous bodies belongs to which transcription factor lineage?
- A PIT-1 ✓
- B T-PIT
- C SF-1
- D GATA3
Correct answer: A. PIT-1
Explanation
WHO 2022 classifies pituitary tumors by transcription factor lineage: PIT-1 marks GH, PRL, and TSH producing tumors including densely and sparsely granulated somatotroph types, where fibrous bodies of keratin 8/18 define the sparsely granulated variant. T-PIT marks corticotroph tumors, SF-1 marks gonadotroph tumors, and GATA3 is not a primary pituitary lineage marker in this scheme.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.