Clinicopathological observation and recent progress of mixed epithelial and stromal tumor of the kidney

Abstract

Objective To investigate the clinical and pathological features of mixed epithelial and stromal tumor of the kidney (MESTK). Methods Histopathological and immunohistochemical characteristics of one csae of MESTK were observed and clinicopathological analysis was implemented combining with the 2016 WHO classification of tumours of the urinary system and male genital organs and other related literatures to investigate the study progress. Results A 32-year-old woman was found a right kidney cystic mass lesion in a physical examination. Gross examination showed that the tumor was lobulated with cystic and solid. Microscopically, the tumor was composed of proliferated and cystically dilated glands admixed with solid stromal area of spindle cells with cellularity and growth patterns. Both epithelial and mesenchymal cells had no obvious atypia and fission. Immunohistochemically, the epithelial elements were positive for cytokeratin diffusely, mesenehymal components were positive for ER, PR, SMA, Vimentin, Desmin and part of CD10. Conclusions MESTK is a rare renal tumor which has unique histopathologie features. The 2016 WHO classification of tumours of the urinary system and male genital organs considers that MESTK is a tumor lineage, of which most biological behaviors are benign. Further studies are needed to elucidate its biological nature for more and more malignant casese and recurrent cases. Key words: Kidney tumor; Mixed epithelial and stromal tumor; Classification