Metanephric adenoma of the kidney

Abstract

Background: Metanephric adenoma is a rare renal neoplasm that is histologically and clinically unique. We found this neoplasm in a 62-year-old female, whose renal tumor was incidentally detected on abdominal ultrasound examination. Methods/Results: Ultrasound, computed tomography and magnetic resonance imaging were compatible with those of renal cell carcinoma. With a diagnosis of renal cell carcinoma, right partial nephrectomy was performed. This tumor showed histologic similarity to developing metanephric tubular epithelium. It was composed of uniformly small epithelial cells, which formed tubules. Conclusions:The patient has been well and healthy for 20 months after surgery. The unique features of metanephric adenoma should be clinically and pathologically recognized because of its invariably benign course.

Metanephric adenoma and solid variant of papillary renal cell carcinoma: common and distinctive features

“…Although most of the MA reported previously were non-encapsulated, 4,9,17,21,[25][26][27]29,35,41 a thin, distinct and mainly discontinuous fibrous pseudocapsule has been described in at least 30 cases. 4,20,23,24,30,32,34,40,42 Conversely, 87% of s-PRCC included in this study were surrounded by a thick fibrous pseudocapsule, and fibrosis was noted at the tumour/normal interface in the three remaining cases. This finding is consistent with one series of five s-PRCC 8 and one case report, 37 where the tumours showed a dense fibrous pseudocapsule.…”

“…45 Other studies have described negative staining for S100 in MA. 9,20,34,35,41 No previous studies have analysed the immunoreactivity of s-PRCC for S100 protein.…”

Metanephric Adenoma of the Kidney: Case Report and Review of the Literature

“…Many of these tumors had been diagnosed previously as nephroblastoma or renal cell carcinoma (4) or have been published under different diagnoses but fitted in the histological image of Mostofi and Brisigotti [5]. Since 1995, 39 cases of tumors with the typical morphology have been reported under the term of metanephric adenoma [3,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

Metanephric Adenoma of the Kidney: A Case Report and Literature Review

“…Therefore, we perform transperitoneal radical nephrectomy as the gold standard for the management. In other cases, Kosugi et al, Imamoto et al, Granter et al reported performing partial nephrectomy [23,24,25].…”