Radiology Corner: Osteoid Osteoma of the Index Finger: Case Presentation and Discussion

Abstract

t o t M o A c 28-year-old, right-hand dominant woman presented with a long history of pain in the proximal phalanx of the right index finger. The nset of pain was insidious and there was no antecedent rauma. There was no swelling or discoloration in the ffected digit. The patient denied any other musculokeletal pain of any kind. She was treated eventually ith excision of a portion of the proximal phalanx of he index finger because of a presumptive diagnosis of Brodie’s abscess. Biopsy examination performed at hat time showed only mucoid tissue. Culture results ere negative. The pain continued, increasing in severty to the point at which the patient was treated with 600 g of gabapentin (Neurontin, Pfizer Inc., New York, Y) daily based on the idea that the patient was sufering from a regional pain syndrome. This did not elieve the pain and she was referred to our center for e-evaluation. On physical examination there was tenderness imediately deep to the scar from a prior incision on he dorsum of the most proximal aspect of the proxmal phalanx of the index finger. There was no limtation in range of motion and no neurologic impairent. Perfusion was excellent with patent ulnar and adial pulses. No obvious joint effusion was present. Radiographs were obtained in the anteroposterior, ateral, and oblique positions. The lateral and oblique adiographs showed a subtle lytic lesion with a thin urrounding sclerotic rim (Fig. 1) and some slight eformity of the base of the proximal phalanx from he prior surgery. There was no periosteal reaction resent. Bone density was normal. After this examination a high-resolution, 3-T magetic resonance image (MRI) of the index finger was btained with and without gadolinium enhancement. his examination showed a 6-mm intraosseous lesion ithin the base of the proximal phalanx. It was urrounded by a rim of black sclerosis on all seuences (Fig. 2). On T2-weighted imaging and after ontrast administration a focal area of periostitis was een with mild elevation of the extensor mechanism. 2