Multifocal renal cortical neoplasia

Abstract

We report a case of multifocal renal cortical neoplasia discovered incidentally at post mortem. A 60 year old man with a one year history of dysarthria, dysphagia, weakness and altered cognitive function, suggestive of Mortor Neurone Disease. Clinically there were no renal symptoms. Biochemical renal function and full blood examination were normal. He died one month after admission with clinical bronchopneumonia. At autopsy the lungs showed evidence of congestive cardiac failure but no bronchopneumonia. The left kidney was of small size, showed reduced cortical thickness, dilated pelvicalyceal system and had three cortical masses between 5 and 35mm In diameter, A fourth Intra-cortical area of yellowish discolouration 3mm in length was also present. Most pathologists now believe that there is no definitive histological difference between renal cortical adenoma and adenocarcinoma and that these two entities reflect a spectrum of the same disease. The 30mm cut off between adenomas and adenocarcinomas is now recognized to be arbitrary, with many lesions under 20mm in diameter capable of metastasing. The four lesions found in this case show similar histological features with some mild cellular atypia. In three of the four lesions there is evidence of capsular or stromal Infillratlon. We propose that we have four separate primary cortical tumors, all probably metachronous, one exhibiting a possible different malignant potential to the others. The patient was also found at post - mortem to have a limbic encephalopathy which is generally considered to be a paraneoplastic lesion in association with pulmonary carcinoma.