Cavitary pulmonary metastases in transitional cell carcinoma of the urinary bladder

About 4% of metastases to the lung eventually evolve into cavitary lesions. The origin of these lesions are squamous cell carcinomas in 69% of cases and adenocarcinomas in the rest. Lung metastases develop in 20% of patients with transitional cell carcinomas of the urinary bladder (TCB), usually as multiple nodules. The cavitation of these metastases is an unusual finding, and a review of the literature has revealed only 7 cases of cavitary metastatic lesions from TCB. We add 2 further cases with cavitary metastases and study their clinical and radiographic features, in comparison with those previously described in the literature.