# Unmasking the Mystery of Renal Neoplasm in a Perimenopausal Woman: A Case Report

## TL;DR

A rare benign kidney tumor called mixed epithelial and stromal tumor was diagnosed and successfully treated in a perimenopausal woman.

## Contribution

This case report adds to the limited literature on mixed epithelial and stromal tumors of the kidney, highlighting their clinical presentation and management.

## Key findings

- A 46-year-old woman was diagnosed with a mixed epithelial and stromal tumor of the kidney through histopathological and immunohistochemical analysis.
- The tumor was successfully treated with laparoscopic-assisted radical nephrectomy and showed a favorable prognosis.
- The case emphasizes the importance of considering rare benign tumors in the differential diagnosis of renal masses.

## Abstract

Mixed epithelial and stromal tumor (MEST) is a benign, complex, and rarely encountered renal neoplasm. This case involves a 46-year-old perimenopausal woman who presented with symptoms, such as abdominal pain, burning sensation during urination, increased urinary frequency, and hesitancy. Computed tomography (CT) urography revealed an exophytic, heterogeneously hyperdense mass originating from the interpolar and lower pole parenchyma of the left kidney, suggesting a neoplastic origin. Due to concerns about malignancy and the presence of local symptoms, a laparoscopic-assisted left radical nephrectomy was performed. Histopathological examination of the excised tissue revealed a biphasic neoplasm consisting of epithelial and stromal elements. The epithelial component exhibited cysts and glands of variable sizes, lined by columnar cells and surrounded by stromal tissue. The diagnosis of MESTs of the kidney was established and confirmed through immunohistochemistry. This unique type of benign kidney tumor can be effectively managed through conservative surgery and is associated with a favorable prognosis.