Case report: Primary squamous cell carcinoma of a tarsal bone.

We describe a rare case of primary squamous cell carcinoma of the cuneiform bone of the foot in a 57-year-old man. In the appendicular skeleton, epithelial carcinomas of bone are usually metastatic deposits, primary squamous cell carcinomas of bone being found more frequently in the skull. A review of the English literature revealed only two other reported cases of primary squamous cell carcinoma outside the skull--one in the ilium and one in the tibia. In our patient, extensive metastatic workup and monitoring during more than 2 years showed no primary focus, supporting the rare presentation of a primary squamous cell carcinoma of bone in the appendicular skeleton.