Case Report Mixed epithelial and stromal tumor of the kidney: report of a rare case and review of literature

Ying Wang, Junqing Yuan, Jihong Wang, Qiang Fu
2015 Int J Clin Exp Pathol   unpublished
Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare benign tumor composed of epithelial and stromal cells. We report a rare male case with detailed clinicopathological data and follow-up information. The patient presented with gross hematuria. Computed tomography (CT) and magnetic resonance imaging study showed a 60 mm×40 mm cystic lesion with thickened septa and minimal contrast enhancement at the lower pole of the right kidney. The patient underwent nephron sparing surgery
more » ... paring surgery (NSS). Intraoperative frozen section showed benign histological features without significant cytologic atypia and mitosis. By additional immunohistochemistry investigations , the epithelial component was positive for cytokeratin-7, high molecular weight cytokeratin, and PAX-8. The stromal component showed strong positivity for vimentin and smooth-muscle actin. This case emphasizes that it is difficult to establish a precise diagnosis of MESTK preoperatively due to lack of any typical radiological features. Thus, intraoperative frozen section is of great clinical significance for NSS with preservation of kidney function. Additionally , regular follow-up is necessary for the MESTK with malignant potential.