Clinicopathological Observation of Metanephric Adenoma and Literature Review

ZHOU Ping; ZHU Zheng-long; ZHANG Wei; DAI Huang-qiong; WU Yan

doi:10.3969/j.issn.1002-3429.2016.12.016

Abstract：Objective To investigate clinicopathological features and key points for diagnosis and differential diagno-sis of metanephric adenoma ( MA) . Methods Clinical data of 1 MA patient was retrospectively analyzed, and the related lit-erature was reviewed. Results The patient was admitted for right upper abdominal pain associated by nausea and vomiting for 3 d. Right renal space-occupying lesion was primarily diagnosed by Bultrasound, CT and MRI examinations, and then surgical treatment was performed. A 8 cm × 5 cm × 3 cm round-like tumor and gray red and gray white in cutting surface with peplos and clear demarcation from the surrounding tissue was cut. Pathological test for intraoperative quickly frozen sections showed that the tumor was composed of smaller cells with the same size, less cytoplasm without nuclear atypia or pathological mitosis. The tumor cells were fine papillary, small tubular arrangement, interstitial little staining, edema in some areas without embryo tissue or calcification. Postoperative immunohistochemical staining showed that MA was positive for Vimentin, WT1, CD57, CKpan, S-100 and Ki67 ( <2%) . Metanephric adenoma was confirmed. The patient was discharged after postoperative re-covery well, and no recurrence was found during 4 years of follow-up. Conclusion MA is a rarely primary renal tumor origi-nating from epithelium, and it is easily misdiagnosed as nephroblastoma by intraoperative quickly frozen sections. It is helpful for accurate diagnosis by well learning its clinicopathological features and conditions.