Ewing Sarcoma of the Distal Part of the Thumb: Allograft Reconstruction to Preserve Function: A Case Report.

Abstract

Ewing sarcoma (ES) is the second most common primary malignant bone tumor in childhood and adolescence after osteosarcoma1. It mainly affects the long bones and the pelvis2. Occasionally, the metacarpals are involved, and more rarely, the phalanges are affected3,4. Treatment for ES may include surgery, chemotherapy, radiation therapy, or a combination of these therapies. Amputation with adjuvant chemotherapy is the treatment of choice for the short tubular bones of the hand. Radiation therapy is not indicated when the digits are involved because of a high rate of complications5,6. We present the clinical course of a case of ES in the distal phalanx of the thumb, along with the radiographic and histopathological findings. We also describe a novel surgical treatment to address functional and cosmetic issues. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A twenty-eight-year-old man presented with pain in the distal phalanx of the left thumb. Symptoms initially manifested as itching and intermittent swelling that had begun three months previously. Over time, this had changed to increasing pain. Physical examination findings included tenderness in the distal phalanx and painful range of motion in the interphalangeal joint. The skin of the affected area was slightly erythematous with induration. There was no history of trauma and there were no constitutional symptoms. Radiographs revealed a lytic lesion with a honeycomb appearance in the distal phalanx, without remarkable cortical expansion or periosteal reaction (Fig. 1). A radionuclide whole-body bone scan showed increased uptake in the distal phalanx but was otherwise normal (Fig. 2). There was high signal intensity of the distal phalanx on the T2-weighted magnetic resonance imaging (MRI) and hypointense signal abnormality on the T1-weighted MRI without soft-tissue involvement (Figs. …