Recurrent Cutaneous Metastasis of Clear Cell Type Renal Cell Carcinoma: Case Report

Abstract

Cutaneous metastases of internal malignancies are rare events occurring rather late in the primary tumors' progression. We are reporting a recurrent case of cutaneous metastatic renal cell carcinoma (RCC) in a 70-year old male present with a nodular lesion on the scalp, who underwent surgical treatment and histopathological diagnosis at the Lady Davis Carmel Medical Center in Haifa, Israel. The patient had consequently twice in his history similar cutaneous lesions on the scalp which were histologically proved to be clear cell type RCC (classic and eosinophilic variant). The currently excised tumor was an oval white dense lobulated, well-demarcated lesion, up to 2 cm in diameter, in the subcutis, without epidermal involvement. The histopathologic findings consisted of atypical cells, arranged in an organoid pattern, with irregularly distributed eosinophilic cytoplasmic granularity. Immunohistochemically, the tumor cells were found positive for CD10, PAX8, EMA, and vimentin, which is consistent with cutaneous metastatic RCC, conventional (clear cell) variant with eosinophilic features. Revision of the histopathologic material from the previous surgeries of the same patient revealed even higher-graded metastatic RCC comparing with the current one. Our reported case and the revised previous one, as well as medical literature data, reflect dissemination of the primary clear sell type RCC and its characteristic metastatic dermatotropism. However, its recurrent metastases, especially to the same body area, are still to be gathered and studied further to make a statistically relevant conclusion about their prognostic value.