A Case of Cavitary Lung Metastasis From Prostate Cancer.

A 79-year-old man was found to have multiple nodules in the lung fields on chest computed tomography. Metastatic lung cancer was suspected; however, the primary site remained elusive. After 1 year of follow-up, both the nodules had enlarged. After 2 years, one of the nodules continued to enlarge; however, the other nodule cavitated and decreased in size. Concomitantly, the previously observed fluorodeoxyglucose uptake in the cavitated nodules disappeared. A comprehensive search for the primary cancer included a thoracoscopic lung biopsy which revealed that these nodules were metastatic lung lesions from prostate cancer. Pathological examination revealed necrosis within these metastatic lesions. To date, only three case reports of cavitary lung metastases from prostate cancer have been published; however, no explanation has been provided for the pathological mechanism of cavitation. To our knowledge, this is the first case to provide a potential explanation for cavitation in metastatic lung lesions from prostate cancer.