Abstract
M.O., a 23-year-old woman, was admitted to the Toranomon Hospital on August, 1976, because of increasingly exertional despnea for several months and recurrent bilateral pneumothorax since 1970. Chest roentgenogram showed a fine reticulomicronodulation of both fields. Lenoangiography revealed left angiomyolipoma. Open lung biopsy revealed changes subsequently recognized as being typical for pulmonary hamartogiomyomatosis.