Mixed Epithelial and Stromal Tumor of the Kidney: A Rare Case Report

Abstract

Mixed epithelial and stromal tumor of the kidney (MESTK) is a rare kidney tumor that is composed of both epithelial and mesenchymal components with solid and cystic architecture. Up to the present, approximately 100 cases have been reported. It was introduced in the World Health Organization 2004 renal tumor classification. Here, we report a 49-year-old female with mixed epithelial and stromal tumor (MEST) in her kidney with no cystic components and no history of hormone use.

Mixed epithelial and stromal tumor of the kidney: A case report

“…Due to this information it can be considered that hormones are a risk factor for this tumor. The clinical presentation of MEST is similar to typical renal tumor (1,2,(4)(5)6,8,(10)(11)(12). However approximately ¼ of known diagnosed MESTs were asymptomatic.…”

“…The risk of malignant transformation in a patient with MEST is highly dependent on the individual characteristics of a tumor. A few cases of malignant transformation have been described in the literature, affecting both epithelium or stromal tumor (1)(2)(3)(4)(5)(6)(7)(8)(10)(11)(12), including transformation into sarcoma, rhabdomyosarcoma, chondrosarcoma or papillary renal cell carcinoma. Thus, the differential diagnosis of MEST should include the above malignancies (1)(2)(3)(4)(5)(6)(7)11,12).…”

“…It has been recognized as a renal tumor since its introduction to the classification by World Health Organization in 2004 (4). MEST is most commonly diagnosed in women of menopausal age (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Most of neoplasms were related to women with history of long estrogen therapy.…”

“…Current treatment strategy is based on surgical operation. Imaging studies usually reveal a cystic lesion with soft tissue components (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Microscopic findings consist of epithelium with mesenchymal tissue (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12).…”

“…Imaging studies usually reveal a cystic lesion with soft tissue components (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Microscopic findings consist of epithelium with mesenchymal tissue (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). The risk of malignant transformation in a patient with MEST is highly dependent on the individual characteristics of a tumor, but in vast majority of patients, the neoplasm was of benign character and the prognosis is good (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12).…”