Contributed by Raj N Hari, MD, Hong Qu, MD and Rajiv Dhir, MD
Published on line in December 2002
The patient was a 74 year old man who presented with a 1 month history right flank pain. His past medical history included a 65 year history of smoking.
Computerized tomography of his right kidney revealed a 10 cm solid mass of the right kidney in the superior pole with no accompanying hydronephrosis.
The specimen (Fig.1) consisted of a right kidney with attached perirenal fat and adrenal gland. The specimen measured overall 16.0 x 9.0 x 6.0 cm. The kidney measured 12.0 x 7.0 x 4.5 cm. The short segment of ureter measured 3.0 cm in length and 0.6 cm in circumference. The lesion consisted of a solid well circumscribed but non encapsulated tumor which measured 10.0 x 5.0 x 4.0 cm, involving the superior pole. The cut surface was solid gray-tan, lobulated with focal areas of necrosis and hemorrhage. The remaining renal parenchyma and adrenal gland was grossly unremarkable.
At low power, H & E sections showed a non encapsulated neoplasm growing in solid sheets of cells divided by thin fibrovascular bundles. (Figs. 2 and 3). At higher magnification, the cells appeared round to polygonal with well defined cytoplasmic borders and pale amphophillic to eosinophillic granular cytoplasm and eccentric nuclei (Fig. 4). The nuclei were small with clumped chromatin, irregular nuclear contours, and moderately with single prominent eosinophillic nucleoli. Some nuclei were noted to have a "raisonoid" appearance (Figs 4 and 5).
The cells were diffusely positive for cytoplasmic staining with Hale's colloidal iron (Figs. 6 and 7).
The cells demonstrated prominent cytoplasmic vesicles on electron microscopy (Figs. 8 and 9).