The symptoms may be similar to those classically associated with renal cell carcinoma, and may include polycythemia, abdominal pain, hematuria and a palpable mass.

They show a uniform architecture of closely packed acinar or tubular structures of mature and bland appearance with scanty interposed stroma.

[8] Differential diagnosis may be quite difficult indeed as exemplified by the three malignancies initially diagnosed as MA that later metastasized, in the report by Pins et al.[9] Brunelli et al. stated that genetic analysis of chromosome 7, 17, and Y may facilitate discrimination of MA from papillary renal cell carcinoma in difficult cases.

[11] MA has been described in the past under other names such as néphrome néphronogène, metanephroider Nierentumor and nephroblastomartiges Nierenadenom (5) but the term metanephric adenoma was suggested by Brisigotti, Cozzutto et al. in 1992 and then widely accepted.

Prior to this report, Nagashima et al. in 1991 had not offered a nosological innovation for their two cases[12] whereas the denomination of néphrome néphronogène proposed by Pages and Granier in 1980 had gone largely undetected.