A Case of Chromophobe Renal Cell Carcinoma

Diagnosis:

A diagnosis of chromophobe renal cell carcinoma was made.

Discussion:

Chromophobe renal cell carcinoma is a distinct subtype of renal cell carcinoma and comprises approximately 5% of neoplasms of the renal tubular epithelium (1).

Chromophobe renal cell carcinoma should be distinguished from renal oncocytoma (2). Chromophobe carcinomas, like oncocytomas, are well circumscribed and can have a mahogany-like colour if they contain a predominant number of eosinophilic granular cells. Additionally, they share similar immunohistochemical profiles. Hemorrhage and necrosis are uncommon.

Electron microscopy is useful in revealing cytoplasmic vesicles which are found exclusively in chromophobe renal cell carcinomas. Hale’s colloidal iron is also useful and will stain the acid mucosubstances within the vesicles. The vesicles disintegrate with paraffin embedding, so it is necessary to obtain glutaraldehyde or formalin fixed tissue for ultrastructural analysis (3). The exact nature of the vesicles is still obscure.

References:

1. Storkel, S., Eble, J.N., Adlakha, K., Amin, M., Blute, M.L., Bostwick, D.G., Darson, M., Delahunt, B., Iczkowski, K. Classification of renal cell carcinoma: Workgroup No. 1. Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Cancer. 80 (5): 987-9, 1997.
2. Crotty, T.B., Farrow, G.M., Lieber, M.M. Chromophobe cell renal carcinoma: clinicopathological features of 50 cases. The Journal of Urology. 154: 964-7, 1995.
3. Bonsib, S.M., Bray, C., Timmerman, T.G. Renal chromophobe cell carcinoma: Limitations of paraffin-embedded tissue. Ultrastructural Pathology. 17: 529-536, 1993.

Introduction and Gross Description