Dictionary.net

A tumor composed, wholly or in part, of cells with the morphologic characteristics of histiocytes and with various fibroblastic components. There are many variants and many names. Superficially located histiocytic lesions behave benignly but deep, benign histiocytomas may invade locally into surrounding tissue. Fibrous histiocytomas can occur anywhere in the body. Superficial lesions are always cured by simple excision; a wider margin of tissue should be obtained for deep, benign types. Local recurrence is uncommon. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1356)