Aneurysmal Fibrous Histiocytoma of the Skin (Description of 2 Cases)

Overview

Authors present two cases of aneurysmal (angiomatoid) fibrous histiocytoma of the skin (AFH) occurring in a 17-year-old boy and a 69-year-old woman. Both tumors were localized on the extremities (forearm and popliteal region) and were of nodular configuration, with moderate elevation upon surrounding skin surface, measuring 10x8 mm and 5x4 mm, respectively. The first tumor was of a firm consistency without change of skin coloration, therefore it clinically imitated an epidermoid cyst. The second lesion had a blue colour and simulated a vascular tumour. Histologically, both tumors possessed spindle and pleomorphic cell population with moderate grade of cellular atypia arranged in irregular storiform pattern with finding of cavernous and slit-like spaces accompanied by recent and elder hemorrhages.

Immunohistochemically, tumor cells were vimentin positive and CD68, CD34 and desmin negative. Cells on the periphery of slit-like, respectively cavernous spaces did not express endothelial marker – CD31. In discussion authors analyze the different clinical and morphological features of this rare type of fibrous histiocytoma when compared to its conventional variants. In differential diagnosis they describe some melanocytic and vascular lesions often clinically similar to AFH.

Key words:
skin – fibrous histiocytoma – anerysmal – angiomatoid