A case of renal metanephric adenoma: Histologic, immunohistochemical and cytogenetic analyses

Abstract

Background: A unique case of metanephric adenoma of the left kidney is reported in a 61-year-old woman presenting with an incidental renal mass on ultrasonography. Methods/Results: On radiographic examination, the presence of hypovascular renal cell carcinoma was suspected and left radical nephrectomy was performed. The resected tumor, measuring 4.9 ¥ 4.7 ¥ 4.5 cm, was well-circumscribed and solid and its cut surface was tan-pink with foci of focal hemorrhage and cystic change. Microscopically, the tumor was composed of uniformly small acini with hyperchromatic round nuclei. Some acini were dilated and occasionally contained glomeruloid-like bodies and psamoma bodies.Immunohistochemically, tumor cells showed positive immunoreaction for vimentin, cytokeratin and Leu7. Cytogenetically, the tumor did not show numerical aberrations of chromosome 7 or 17 by fluorescence in situ hybridization. Conclusions:The patient is alive without recurrence or metastasis 4 years after surgery. Metanephric adenoma must be differentiated from other renal tumors, particularly Wilms' tumor or low-grade renal cell carcinoma. Immunohistochemical and cytogenetic analysis may be helpful in difficult cases.

Detection of chromosome copy number alterations in metanephric adenomas by array comparative genomic hybridization

“…The later series all showed contrary results. 4,8,11,[13][14][15] Our aCGH analysis, as well as that reported by Szponar et al, 18 also failed to identify gains of chromosomes 7 and 17. Given that papillary renal cell carcinoma may exhibit a solid growth pattern, it is highly plausible that the presumed metanephric adenomas with trisomies of chromosomes 7 and 17 in the series of Brown et al actually represented solid variant of papillary renal cell carcinoma.…”

“…Previous karyotyping of a total of five cases revealed negative findings, with the exception of a dual balanced translocation of t(1;22)(q22;13) and t(15;16)(q21;p13) in one case. 5,[8][9][10][11][12] One fluorescence in situ hybridization (FISH) study indicated gain of chromosomes 7 and 17 and loss of Y chromosome-the cytogenetic markers of papillary renal cell carcinoma-in 8 of 11 metanephric adenomas. 13 However, subsequent FISH analyses revealed normal copy numbers for chromosomes 7 and 17.…”

“…13 However, subsequent FISH analyses revealed normal copy numbers for chromosomes 7 and 17. 4,8,11,14,15 A deletion in chromosome 2p was the only genetic abnormality described in one tumor, and a tumor suppressor gene region on 2p13 was delineated. 16,17 Most recently, a study employing array comparative genomic hybridization (aCGH) reported no copy number changes in six cases of metanephric adenoma.…”

Atypical metanephric adenoma – a case report and review of literature

“…Positive reaction with CK and EMA has been confined to areas showing papillary cystic tubular configurations [7,8] as was also seen in our case.…”

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].…”