Dermatofibroma with granular cells: a report of two cases.

We describe two examples of an unusual variant of dermatofibroma (DF) in which areas of granular cells were a prominent feature. The diagnosis of DF was confirmed by immunohistochemistry and by ultrastructural studies. Granular cell changes can be observed in numerous benign and malignant cutaneous tumors of different cellular lineage. Cellular granularity is a nonspecific phenomenon characterized by intracytoplasmic accumulation of lysosomes and may cause diagnostic difficulties. Traumatic factors may be involved in the pathogenesis of cellular granularity.