Fig. 3From: The undifferentiated carcinoma that became a melanoma: Re-biopsy of a cancer of an unknown primary site: a case reportSeveral subcutaneous recurrent tumors developed after 18 months. A biopsy showed cells with a growth pattern, cellular features, and nuclear features similar to the tumor resected in 2012 seen by hematoxylin, eosin and saffron staining (a), but a change to negative staining for cytokeratin AE1/AE3 (b) and now positive staining for S100 (c)Back to article page