Squamous cell carcinoma in chronic osteomyelitis. Report of a case and review of the literature.

Malignant change at the site of a chronic osteomyelitis, a rare condition, is reported in a 45-year-old man, along with a review of the literature. This patient with a 30-year history of chronic osteomyelitis of the right femur and an intermittently discharging sinus had a large abscess in the lower thigh. The abscess was drained, and an ulcer developed at the mouth of the sinus tract. Soon afterward, he sustained a pathologic fracture through the lower femur. Biopsy specimens of the ulcer showed a well-differentiated squamous carcinoma. An amputation was performed at the level of the proximal 10 cm of the femur. The patient remains well 18 months later with no clinical or radiologic evidence of metastases. Changes in character of a previously innocuous osteomyelitis sinus tract should arouse suspicion of neoplastic transformation. Biopsy of various depths of the sinus tract, including the bone marrow, is essential. Early amputation for squamous cell carcinoma is indicated and offers a good prognosis.