KIDNEY - Adenoma (oncocytoma)

One pole of the kidney is expanded by a spherical tumour, some 10 cm. in diameter, which appears to be encapsulated. The external surface is smooth for the greater part, although there are some obviously nodular areas at the upper pole. The cut surface shows a central fibrous area surrounded by a nodular, tan-coloured, tumour in which there are several small areas of haemorrhage.
This woman was admitted to hospital at the age of 36 for investigation of the liver enlargement; this had been noted on routine examination several months before. An arteriogram showed a large well-circumscribed vascular tumour, some 12 cm. in diameter, arising from the lower pole of the right kidney. This was removed, and the histology was that of an adenoma arising from the epithelium of the proximal tubes of the kidney (Oncocytoma). At the present time, there have been some 28 of these reported in the world literature, and all these have been benign. For further information see 'Cancer', 38, 906, 1976.