PAINFUL MASS OF THE FOREARM IN A 65-YEAR-OLD MAN

Abstract

We describe a 65 year old gentleman presented with a three month history of painful lump in the right forearm which was subsequently confirmed to be osteosarcomatous degeneration in the Paget’s disease of the radius.

A 65 year old gentleman presented with a three month history of painful lump in the right forearm with overlying redness thought by the patient to be the result of recent sun exposure. On physical examination, there was an 8 x 10 cm sized mass over the radial aspect of the right forearm. The mass was soft to firm, mildly tender to palpation, fixed to bone and deep-seated. There was erythema with increased warmth over the area of the mass. There was significant restriction of forearm supination and pronation. Neurovascular examination was normal. Chest x-ray was normal. Plain x-ray of the affected forearm revealed a mixed pattern (both sclerotic and lytic appearance) affecting the entire diaphyseal portion of the radius with soft tissue extension in the mid-shaft. There were alterations in the trabecular pattern of the bone, thickened cortices, encroachment of the medullary space and an increase in the size and deformity of the entire length of the radius with cortical destruction sparing the ulna. Bone scan showed multiple hot foci with an increase uptake in the sacrum, left hemipelvis, L3 vertebra and intensely increased uptake over the right radius. On the 10th day of presentation, an open incisional biopsy was done. Microscopy showed a high grade sarcomatous tumour with areas of osteoid formation. There was evidence of vascular invasion. The presence of preexisting Paget’s disease of bone was confirmed in the specimen. An above elbow amputation was done 4 weeks from the date of biopsy and after full staging. The patient died 16 months with multiple metastases from the date of diagnosis.

Any patient with Paget’s disease who develops new pain in a previously pain-free area of Paget’s disease, or worsening of pain, or a painful progressive mass or a lytic area in sclerotic Paget’s bone should be evaluated for possible sarcomatous degeneration.