Multiple pulmonary hamartomas penetrating the visceral pleura: report of a case.

We report a case of multiple pulmonary hamartomas with a very unusual growth pattern. A 63-year-old woman underwent video-assisted thoracic surgery to investigate a round shadow seen on a routine chest radiograph. We found two tumors in the right S4, penetrating the visceral pleura and adhered to the right upper and lower lobes, respectively. Both tumors were removed and diagnosed histologically as pulmonary hamartoma. We hypothesized that these subpleural hamartomas might have grown invasively to penetrate the visceral pleura.