The Great Impostor: A challenging case of small‐cell melanoma with isolated adrenal metastasis

Abstract

Section from the rectal biopsy showing tumour arranged in sheets and nodules. The tumour cells are highly pleomorphic, having central to eccentrically placed round nuclei, coarse chromatin, prominent macronucleoli and a moderate amount of cytoplasm (H&E; A:2×, B:10×, C:20×, D:40×); (E-H): On immunohistochemistry, the tumour cells are positive for HMB45 (H; 20×), show retained nuclear expression of INI-1 (G; 20×) and are negative for cytokeratin (E; 20×) and SALL4 (F; 20×).