Delayed appearance of metastatic renal cell carcinoma subcutaneously in the left fifth toe after ipsilateral...

Pedal metastases from visceral cancers, while rare, constitute a consideration in the presence of an otherwise unexplained mass in the skin, subcutis, or bones of the foot. Metastatic lesions may be presenting signs of visceral malignant tumors, or may remain occult for years after extirpation of the primary visceral lesion. The presented case depicts sudden activation and growth of an occult renal cell carcinoma metastasis in the subcutaneous tissue of a 69-year-old man's left fifth toe, 10 years after ipsilateral nephrectomy. Cytogenetic studies correlate with tumor histologic patterns and help to predict heritability, uni- or bilaterality, and local and systemic biologic behavior of renal cell carcinoma, thereby aiding in prognosis and treatment planning.