Composite renal cell carcinoma and angiomyolipoma: A study of the histogenetic relationship of the two lesions

Abstract

The purpose of the present study was to investigate the possible histogenetic relationship of renal cell carcinoma (RCC) and angiomyolipoma (AMYL) occurring in the same renal nodule by examining two cases of composite RCC and AMYL in patients without stigmata of tuberous sclerosis and by reviewing the medical literature of similar cases. Case 1 represents an epithelioid variant of AMYL with multiple additional nodules of typical AMYL in a surgically removed kidney. The patient subsequently developed a lesion consisting of a mixture of epithelioid variant of AMYL and RCC 24 months later in the retroperitoneum and, an additional 4 months later, in the liver. The RCC cells resembled mononucleated epithelioid cells of the epithelioid AMYL except that they were focally reactive with epithelial membrane antigen (EMA) in the retroperitoneum and focally reactive with both EMA and cytokeratin (CK) in the liver. Case 2 consisted of a typical AMYL admixed with a chromophil cell RCC. A review of the medical literature revealed seven additional cases with histopathological findings similar to this case. All cases had multiple foci of typical AMYL. Immunostaining results are available in five tumors. Chromophil RCC showed variable reactivity with CK and EMA. In addition, RCC in the two cases in the present study also displayed a positive reaction with mucin staining and a positive reactivity with carcinoembryonic antigen. There appears to be a spectrum of histopathological and immunohistochemical changes from the epithelioid variant of AMYL through a mixed epithelioid AMYL/RCC to chromophil RCC in three successive specimens in case 1. Moreover, the intimate admixture of AMYL and RCC and the similar expression of epithelial markers of RCC in the two cases in the present study, as well as other cases in the literature, suggest that some RCC develop from the same precursor cell as AMYL or from a component of AMYL.

Fine Needle Aspiration Biopsy of Epithelioid Angiomyolipoma

“…Unlike typical AMYL, which has a benign clinical course, epithelioid AMYL is often associated with an unfavorable evolution, including recurrence of the lesion in the retroperitoneum and liver and eventual death. 2,3 We report a case of recurrent epithelioid AMYL diagnosed by fine needle aspiration biopsy (FNAB) and describe the cytologic appearance of the lesion, with an emphasis on immunocytochemical studies for differentiation of this lesion from epithelial neoplasms of the kidney.…”

Renal cell carcinoma arising in a long pre‐existing angiomyolipoma

“…Mai et al . reported the possible origination of RCC from AML, 12 but Cheng et al . concluded that AML and RCC were coincidentally present at the same location 4 .…”

Lymph nodal involvement by renal angiomyolipoma

“…Concomitant renal cell carcinoma was observed in 26% of patients with angiomyolipoma and tuberous sclerosis, while 2–7% of patients with pure renal angiomyolipoma had evidence of renal cell carcinoma. 4,21–26 …”

“…Concomitant renal cell carcinoma was observed in 26% of patients with angiomyolipoma and tuberous sclerosis, while 2-7% of patients with pure renal angiomyolipoma had evidence of renal cell carcinoma. 4,[21][22][23][24][25][26] Nodal angiomyolipoma associated with renal angiomyolipoma was not described again until 1965 and 40 more cases have been described since then. 1,4,5,[9][10][11][12][13] The actual incidence of nodal involvement with angiomyolipoma is unknown and may never be assessed because fewer radical nephrectomies will be performed for angiomyolipoma.…”