[Glomus tumor of kidney: Unusual location of a rare mesenchymal tumor].

Glomus tumors are rare mesenchymal tumors, mostly cutaneous or subcutaneous, for which visceral locations have been described. We report the case of a solid renal glomus tumor incidentally discovered in a 60-year-old patient. The tumor was 25mm wide and was mainly composed of glomus cells expressing smooth muscle actin and vimentin. These cells were negative for cytokeratin, neuroendocrine markers and renin. Glomus cells were associated with blood vessels and bundles of smooth muscle fibers. The purpose of this work is to report the diagnostic criteria, signs of malignancy and main differential diagnosis of these rare tumors whose prognosis is usually excellent after complete surgical resection.