A 9-year-old boy has bitemporal hemianopia and growth failure. MRI shows a suprasellar mass with cystic and solid components and coarse calcification. Histology shows nests and cords of squamous epithelium with peripheral palisading, wet keratin, and stellate reticulum. Immunohistochemistry would show nuclear accumulation of:

• A Chromogranin A
• B Synaptophysin
• C Beta-catenin ✓
• D Calcitonin

Explanation

Adamantinomatous craniopharyngioma, the common pediatric suprasellar tumor, characteristically contains wet keratin, palisaded squamous epithelium, and calcification, and is driven by activating CTNNB1 mutations of the Wnt signaling pathway, producing nuclear beta-catenin accumulation. Synaptophysin and chromogranin mark neuroendocrine tumors such as pituitary adenomas, and calcitonin marks medullary thyroid carcinoma. The papillary craniopharyngioma of adults instead carries BRAF V600E mutations.

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.