Desmoid tumour of the distal forearm involving the distal radioulnar joint.

A 32-year-old woman presented with progressive pain and swelling of the left wrist for 6 months. Physical examination revealed a firm, tender, oval swelling over the left wrist. X-rays showed a pressure effect on the distal radius and ulna. Magnetic Resonance Imaging (MRI) revealed a well-defined, asymmetrical, dumbbell-shaped soft-tissue lesion involving the interosseous region of the distal forearm and extending until the distal radioulnar joint (DRUJ). Core needle biopsy confirmed the diagnosis of desmoid tumour. Marginal excision of the tumour was done. At the 2-year follow-up, the patient was doing well and had painless and improved left wrist motion. Desmoid tumour involving the DRUJ has not been previously reported. We, through this case, report new observation and discuss the epidemiology, investigation of choice, treatment modalities, and the need for a regular follow-up for appendicular desmoid tumours.