Abstract
Patients with renal cell carcinoma rarely experience metastatic disease, occurring in approximately 25% of patient cases (1). Only 1.0-3.0% of these patients experience cutaneous metastasis and often occurs as a late manifestation of the disease (2, 3). Metastatic RCC to the skin most commonly involves the scalp, followed by the chest and the abdomen. We present a unique case of a 64-year-old male patient with a history of RCC who presented to the ED with a blanching, purpuric nodule on the right lateral thigh. A 4mm punch biopsy was performed to rule out metastatic disease. The pathological examination revealed a dense dermal infiltrate of atypical cells, with variably prominent nucleoli and moderate vacuolated cytoplasm, with areas of cytoplasmic clearing. Immunohistochemisty was positive for cytokeratin AE1/AE3, Cam5.2, and PAX8. The histopathologic findings were consistent with metastatic renal cell carcinoma to the skin. To these authors knowledge, no previous reports in the literature describe a metastatic RCC to the cutaneous thigh. Unfortunately, evidence of skin metastasis has a poor prognosis and likely indicates late stage disease. However, with appropriate surgical excision, disease-free follow up is achievable. Our case contributes more information to the limited consolidation of rare oncologic cutaneous presentations, as the disease burden causes significant patient morbidity and mortality.
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