Atypical Fibrous Histiocytoma

The findings are very characteristic for a so called atypical fibrous histiocytoma. An atypical fibrous histiocytoma is characterized by areas of enhanced cellular atypia in a lesion that is otherwise quite characteristic for a conventional benign fibrous histiocytoma, a finding that is certainly well exemplified by this case. In the area of enhanced atypicality the lesion also has some overlapping features of an aneurysmal fibrous histiocytoma. The atypical fibrous histiocytoma along with the aneurysmal fibrous histiocytoma, deep penetrating cellular fibrous histiocytoma and epithelioid histiocytomas are among those that can recur and rarely metastasize.