DESMOPLASTIC FIBROBLASTOMA - A REPORT OF 7 CASES

Seven cases of desmoplastic fibroblastoma, a distinctive fibrous soft- tissue tumor, are presented. The patients, four men and three women, r anged in age from 25 to 83 years (median 57 years). The tumors were lo cated in the neck (two cases), the upper arm, the forearm, the shoulde r, the lateral thigh, and the dorsum of the foot (one case each). Thre e neoplasms were intramuscular, and four were subcutaneous (two of the latter were directly on top of muscle). Maximum tumor dimension varie d from 1.8 cm to 9 cm (median 3.2 cm). Grossly, the lesions were well circumscribed, firm, and white to gray to tan on cut section. Microsco pically, they were composed of medium-sized to large ''reactive appear ing'' spindled to stellate fibroblasts sparsely distributed in a fibro myxoid to densely fibrous background; mitotic figures were very rare o r absent, tumor necrosis was not seen, and vascularity was low. The tu mor border was generally well delimited, although interdigitation with adjacent muscle or fat was present in areas in some cases. Follow-up ranging from 15 months to 46 months (median 28 months) after excision was available on five patients. No recurrences were observed.