Coincident detection of lung metastasis of prostate cancer and primary lung cancer: A case report.

We report an extremely rare case of 79-year-old man, who was discovered with coincidental lung metastasis of prostate cancer and primary lung cancer. The patient presented with low prostate-specific antigen and two lung lesions: one in the right lower lobe, and one in the right upper lobe, 3 years after he was treated with external beam radiotherapy for Gleason score 4+3=7, cT3aN0M0 prostate cancer. A computed tomography-guided needle biopsy of a nodule in the right lower lobe revealed suspicious metastasis of prostate cancer. Thoracoscopic excisions of both lesions were performed, and each lung lesion was diagnosed as being metastatic prostate cancer and primary lung cancer.