Malignant transformation in chronic osteomyelitis.

INTRODUCTION: Carcinomatous degeneration is a rare and late complication developing decades after the diagnosis of chronic osteomyelitis.

OBJECTIVES: To present the results from a retrospective study of six cases of squamous cell carcinoma arising from chronic osteomyelitis.

METHODS: Six cases of chronic osteomyelitis related to cutaneous squamous cell carcinoma were identified. The cause and characteristics of the osteomyelitis were analyzed, as well as time up to malignancy, the suspicion signs for malignancy, the localization and histological type of the cancer, and the type and result of the treatment.

RESULTS: The mean time between osteomyelitis onset and the diagnosis of malignant degeneration was 49.17 years (range: 32-65). The carcinoma resulted from tibia osteomyelitis in five cases and from femur osteomyelitis in one. The pathological examination indicated cutaneous squamous cell carcinoma in all cases. All the patients were staged as N0M0, except for one, whose lomboaortic lymph nodes were affected. The treatment consisted of amputation proximal to the tumor in all patients. No patient presented signs of local recurrence and only one had carcinoma metastasis.

CONCLUSION: Early diagnosis and proximal amputation are essential for prognosis and final results in carcinomatous degeneration secondary to chronic osteomyelitis.