Cutaneous
metastasis of
renal cell carcinoma (RCC) is very rare. The author herein report two cases of RCC with cutaneous
metastasis. Case 1: is a 75-year-old man with right
lumbago. Imaging modalities including CT and MRI revealed a right renal
tumor.
Nephrectomy was performed. Pathological diagnosis of the renal
tumor was RCC of clear cell type (Fuhrman's grade II). He denied follow-up. Nine years later, he (at the age of 84 years), a neck skin
tumor emerged. Clinical diagnosis was
hemangioma. Imaging modalities including CT and MRI showed several
tumors in both lungs. The resection of the neck
tumor was performed. The
tumor was composed of clear cell type arranged in a trabecular pattern. Immunohistochemically, the
tumor cells were positive for pancytokeratins,
cytokeratin 18, CD10, Ki-67 (labeling=13%), but negative for CD34,
factor-VIII-related antigen, CEA, EMA, melanosome (HMB45),
S100 protein, p53, and HepPar-1. Metastatic RCC was diagnosed. Despite
interferon therapy, he died of 6 months after the second admission. Case 2 is a 66-year-old man with gross
hematuria. Imaging modalities revealed left renal
tumor. A
nephrectomy was performed. The pathological diagnosis was RCC of clear cell type (grade II). The
tumor was invasive into the renal pelvis. He was treated by chemoradiation, but
metastases of lungs, skin (thigh), and lib emerged, and died of
cachexia 9 months after the admission. Necropsy of the skin
tumor was performed. The skin
tumor was composed of clear cells arranged in a trabecular pattern. Immunohistochemically, the
tumor cells were positive for pancytokeratins (AE1/3,
CAM5.2), CD10, p53, and Ki-67 (labeling=20%), but negative for CD34,
factor-VIII-related antigen, CEA, melanosome (HMB45),
S100 protein, and HepPar-1. A diagnosis of RCC (grade II) was diagnosed.