Renal Myxoma, an Incidental Finding

Myxomas are mesenchymal tumors commonly found in the heart and skin. Renal myxomas are rare, having only been documented 14 times. Our case is a 55-year-old woman who presented to our clinic after a right renal mass was incidentally found on CT. Evaluation with MRI showed a mass that appeared to arise from the supero-medial cortex of the right kidney. As the imaging was concerning for renal cell carcinoma, the patient underwent a partial nephrectomy. Microscopic examination showed a well-circumscribed mass with polygonal to spindle-shaped cells in a granular eosinophilic cytoplasm. Immunohistochemical staining for CD-10, Desmin, HMB-45, and Pankeratin were negative.