Renal myxoma: An unforeseen diagnosis

Myxomas are rare tumours that can be found in many anatomical locations. There are only 17 cases of renal involvement documented. Our case is an 85 year-old man followed in our consultation with recurrent hematuria after a transurethral resection of a bladder tumour. Evaluation with CT showed a solid lesion with 23 x 18 mm partially obliterating the left inferior calyx. The patient underwent a left nephroureterectomy. Microscopic examination showed a mass within renal parenchyma adjacent to the renal pelvis composed of plump mildly atypical spindle cells distributed in a copious myxoid matrix. Immunohistochemical staining for Vimentine, Pankeratin (AE1/AE3-), CD34, CD31 and smooth muscle actin were negative. With these histopathological and immunohistochemical findings, the case was diagnosed as renal myxoma.