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×).