Tumor crescents from intraglomerular metastases

A patient who died of bronchopneumonia complicating metastatic carcinoma of the larynx was found to have crescentic glomerulonephritis at autopsy. Further examination revealed the crescents to be tumor deposits in Bowman's space of most glomeruli, while no tumor was found elsewhere in the kidneys. The relevance of this observation to the possible mechanism of crescent formation is discussed.