Two cases of rare desmoid fibromas are being reported, localised in the extremities. After a literature review of these tumors, the clinical characteristics are pointed out and difficulties in therapy discussed. The tumors occasionally appear on the forearm or the thigh of juvenile patients and show a similar development. In the first case, 7 operations with resection of the n. medianus and n. ulnaris were necessary to prevent a recurrence. In the second case, we saw a solitary and rapidly growing tumor, surrounding the sciatic nerve with a great tendency to recur.