Comparison of the morphology of renal cysts and cystic renal tumors

Judit KOVÁCS, Szabolcs GOMBA, Mónika ZILAHY

Department of Pathology, University Medical School of Debrecen, Debrecen, Hungary


Renal tumors appear uncommonly with cystic changes. They may develop due to necrosis though well-formed real cysts are also known. Such lesions may present problems in distinguishing them from benign renal cysts. Conditions leading to cyst formation are not known, however cell proliferation, altered extracellular matrix production and oncoprotein expression have been reported in cystic renal disorders. In the present study, we analysed the morphological features of 23 cystic renal tumors in comparison with 16 benign cysts using immunohistochemical and lectin binding methods. By our knowledge there has not been any piblication on such studies. The cystic renal tumors were represented predominantly in males and the size of the cysts was slightly larger than that of benign cysts. Tumorous cysts shared similar morphological appearance to solitary and multilocular cysts. They all showed strong epithelial membrane antigen reactivity on the luminal surface of the cells indicating distal tubular origin. Cell proliferation and p53 expression proved to be low excluding their role in the formation of the cysts. The amount of extracellular matrix and basement membrane was increased with an elevated type IV collagen and reduced fibronectin content. Polycystic kidney disease is different from tumorous cysts as cell proliferation, p53 oncoprotein expression and the composiition of extracellular matrix proved to be the opposite. As renal cell tumors arise from proximal tubules, neoplastic or metaplastic differentiation toward distal tubular direction seems to be the key even in cyst formation. Altered cell-matrix or cell-cell contact can modulate this transformation providing a basis for further results. Pathology & Oncology Research, Vol 3, Nr 4, 272-277, 1997

Key words: renal cysts; renal tumors; tubular markers; cell proliferation; immunohistochemistry

Received: Aug 18, 1997; accepted: Sep 17, 1997
Correspondence: Judit KOVÁCS, Department of Pathology, University Medical School of Debrecen, Debrecen H-4012, Hungary; Tel: (36)(52)417063, Fax: (36)(52)417063; E-mail:

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