Extracapillary tumourous metastatic crescents in glomeruli of the kidney.

This report describes intraglomerular tumor cell metastases, as a rare pathologic observation. Specimens of one hundred autopsy cases (each having extrarenal carcinoma) were examined by light microscopy, and in seven of them metastatic crescents were found in the urinary space of the Bowman's capsule. The capsule itself and the layer of the parietal epithelium seemed to be intact. Glomeruli with metastases in five cases were near or inside the extraglomerular metastatic tumor mass. This phenomenon must be distinguished from metaplastic transformation of the glomerular capsular epithelium.