Mixed epithelial and stromal tumour of kidney

Mixed epithelial and stromal tumour of kidney is a recently described, rare entity and includes cases previously termed as cystic hamartoma of renal pelvis and adult mesoblastic nephroma. We report a case of 36 years old female who presented with a history of recurrent loose stools for 5 years. During ultrasound abdomen, a solid right renal mass was incidentally found in upper pole of right kidney. On gross examination it was a 3.5 cm diameter mass which was microscopically composed of both epithelial and stromal components in the form of cystically dilated tubules and fascicles of spindle shaped cells. These cells stained positive for alpha smooth muscle actin, desmin, progesterone receptors and negative for estrogen receptors.