[Clinicopathological study of pulmonary hamartoma with special reference to 6 patients who also had another tumor]

We studied 22 patients in whom intrapulmonary hamartoma was diagnosed between 1975 and 1994. Twelve were men and 10 were women, and their ages ranged from 20 to 72 years (averaged: 52.5). The sizes of the hamartomas ranged from 5 mm to 3 cm. Five patients also had other types of cancer (ling 3, colon 1, thyroid 1) and one had a mediastinal tumor (1). In those 6 patients, the hamartomas had to be distinguished from intrapulmonary metastasis. In 2 of those 6, thoracoscopic surgery was useful for obtaining sufficient materials for diagnosis. In one patient immunohistochemical analysis with anti-PCNA (proliferative cell nuclear antigen) antibody was useful in distinguishing leiomyomatous hamartoma from benign metastatic leiomyoma.