Desmoplastic fibroma is a rare benign tumor of bone and fibrous connec
tive tissue, First described by Jaffe(1) in 1958 as a benign intraosse
ous fibrous tumor, it is characterized by abundant collagen formation
with histologic features resembling the desmoid tumor of the abdominal
wall. The appearance on x-ray films is characterized by osteolytic ch
anges arising centrally from bone with expanding radiolucency and cort
ical thinning, Periosteal reaction is not present and there is marked
bone destruction, most often in the metaphysis.(2) Desmoid tumors have
rarely been reported in the upper extremity, Prior authors have repor
ted on cases involving the hand as well as the bones of the forearm.(3
-7) A review of the literature finds less than 20 cases of desmoid tum
ors involving the upper extremity. The present report describes a desm
oplastic fibroma occurring in the ulna of a skeletally immature indivi
dual with neurofibromatosis.