Fig. 1From: The undifferentiated carcinoma that became a melanoma: Re-biopsy of a cancer of an unknown primary site: a case reportTumor resected in 2012. The resection revealed malignant epithelioid cells with pale eosinophilic cytoplasm and pleomorphic nuclei with vesicular chromatin; hematoxylin, eosin and saffron staining (a). The resection revealed a positive reaction for cytokeratin AE1/AE3 (b). Scattered cells stained positive for S100 (c) and CD68 (d), representing tumor-associated macrophages, but tumor cells were S100 negativeBack to article page