1 146 THE JOURNAL OF BONE AND JOINT SURGERY Squamous-Cell Carcinoma Complicating Chronic Osteomyelitis *

tion in patients with chronic osteomyelitis requires differentiation between benign, penetrating epithe-lioma and invading, low-grade squamous-cell carci-noma. Although most lesions are low-grade, analysis of the case histories of twenty-three patients treated at the Mayo Clinic indicates that these tumors do metastasize. When malignant-appearing epithelium invading bone is identified, ablative surgery is mdi-cated. Inadequate surgical treatment resulted in the deaths of two patients in our series. Routine regional lymphadenectomy at the time of amputation seems un-necessary. Regional lymphadenopathy persisting for six to twelve weeks after amputation warrants surgical intervention. With prompt, aggressive surgical treat-ment, the prognosis for patients with squamous-cel