Granular cell variant of atypical fibroxanthoma. A case report.

UNLABELLED: We report a case of an 84-year old female with granular cell atypical fibroxanthoma. The patient had an exophytic cutaneous tumor without ulceration localized on the left thigh. Histologically, the tumor consisted of a large epitheloid and spindle cells with a moderate to abundant amount of eosinophilic granular cytoplasm. The nuclei were irregular with coarse chromatin and some exhibited prominent nucleoli. Some of the tumor cells displayed atypical bizarre pleomorphic nuclei. Mitotic figures were sparse. Immunohistochemically, the tumor cells showed diffuse positivity for vimentin, CD10, NKi/C3 and CD68 (KP1). CD68 (PGM1) was positive only focally. Other markers examined, which included Melan A, HMB45, S-100 protein, cytokeratin AE1/AE3, desmin, h-caldesmon, α-smooth muscle actin, NSE, CD1a, CD34, and CD31 were negative. A granular cell variant of atypical fibroxanthoma is rare, and only a few cases have been reported in the literature to date.

KEYWORDS: dermal tumor - atypical fibroxanthoma - granular cells - cytoplasmatic granules - granular cell tumors.