Osseous lesions of the distal ulna: atypical location--unusual diagnosis. Report of three cases with similar imaging and different pathologic diagnoses.

Three cases with destructive bone lesions of the distal end of the ulna caused by different pathologic entities (Ewing's sarcoma, osteosarcoma, rheumatoid pseudotumoral synovitis) are presented, all with similar clinical and comparable x-ray and magnetic resonance imaging features. Although the distal end of the ulna may be resected without significant functional impairment, careful evaluation of treatment strategies compatible with oncologic standards is warranted.