腎臟上皮間質瘤：個案報告及文獻分析

潘柏諺¹、高毓婷²、莊正鏗¹

¹林口長庚紀念醫院 外科部 泌尿科系；²長庚大學 醫學生

Mixed epithelial stromal tumor of the kidney: Case Report and Literature review

Pai-Yen, Pan, MD¹., Yuting Kao, MD²., Cheng-Keng Chuang*, MD, PhD¹.

¹Divisions of Urology, Department of Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan

²Medical Student, School of Medicine, Chang Gung University

Case report:

  Mixed epithelial stromal tumor of the kidney (MESTK) is a rare tumor that consists of epithelial and stromal cell. We report a 44-year-old Taiwanese male, with no history of hormonal therapy, who was found with a left renal tumor by self-health examination. He was a hepatitis-B virus carrier, and had smoking and alcohol history. He began taking aspirin since he received left anterior descending coronary artery stenting for anterioseptal myocardial infarction. His mother had breast cancer history. Abdominal computed tomography showed an 11 x 15 cm enhanced heterogeneous soft tissue mass with calcification and minimal fatty content. There were no enlarged lymph nodes found. The image favored a left renal angiomyolipoma with less fat content, malignant renal tumor was also considered. He subsequently received radical left nephrectomy. The surgical specimen disclosed a 1076 gm left kidney, the size was 19.5 x 13.7 x 11.7 cmThe tumor was in the low pole and it measured 14.5 x 11.7 x 10.8 cm and was composed of benign epithelial and stromal cells. Immunohistochemically, the tumor expressed markers for progesterone, smooth muscle actin and CD34, but not for estrogen. The diagnosis of mixed epithelial stromal tumor of the kidney was confirmed.

  The patient discharged 8 days after the surgery. Up to the writing of this report, there was no recurrence and his renal function was normal.

Materials and Methods:

  MESTK has been reported as a well-circumscribed multi-septate cystic mass with solid components and thick or thin septa on both the CT and MR imaging. It is difficult to distinguish MESTK from multilocular renal cell carcinoma. The diagnosis of MESTK usually depends on histological characteristics and immunohistochemical (IHC) staining of the tumor. Of MESTK, 62% estrogen receptor and 85% progesterone receptor were expressed in the stromal component. Focal progesterone receptor was expressed in malignant MESTK but estrogen receptor was negative expression in almost all malignant cases. Mesenchymal markers such as vimentin, CD 34, and desmin were positive in stromal cells. Additionally, CD10, calretinin, and inhibin are expressed in some of the MESTK cases. Furthermore, bcl-2 and CD99 were expressed in another case. In our case, the tumor expressed markers for progesterone, smooth muscle actin and CD34, but not for estrogen.

Conclusions:

  MESTK is a benign renal tumor with malignant potential. IHC staining may aid in diagnosis of this rare tumor which stain positively for progesterone, smooth muscle actin and CD34, but negative for estrogen. Almost every mixed epithelial and stromal tumors of the kidney are benign. Nevertheless, these tumors do have malignant potential. We should keep in mind that patients receiving hormonal therapy have a higher risk of developing cystic renal tumor, irrespective of their gender.