Multiple Pulmonary Hamartomas Masquerading as Metastatic Lung Tumors: A Case Report

Abstract

Background. The majority of pulmonary hamartomas are recognized as solitary tumors. It is difficult to differentiate multiple pulmonary hamartomas from pulmonary malignant nodules in a patient who has undergone previous surgery for metastatic lung tumor. We report an extremely rare surgical case of multiple pulmonary hamartomas. Case. A 57-year-old woman with an abnormal chest radiograph was referred to our hospital in August 2004 for further evaluation. Chest radiography and computed tomography showed multiple nodular lesions in the posterior basal segment of the right lung. She had undergone surgery for rectal cancer in September 2002 and had undiagnosed bilateral pulmonary nodules identified at that time. Because the pulmonary nodules in the left lung increased in size, partial resection of the left upper lobe was performed in February 2003. Postoperative histopathologic diagnosis of the lung tumor was metastatic adenocarcinoma originating from the rectal cancer. She underwent chemotherapy starting in March 2003, but an increase in number and size of the pulmonary nodules in the right lower lobe was demonstrated on chest films. She underwent partial resection of the posterior basal segment of the right lung by video-assisted thoracoscopic surgery in September 2004 to remove all nodules. Postoperative histopathologic examination of the resected specimens revealed multiple pulmonary hamartomas consisting of various-sized bronchioles without a cartilageous component. She recovered uneventfully and there have been no signs of recurrence for 40 months since the pulmonary resection in February 2003. Conclusion. We encountered an extremely rare surgical case of multiple pulmonary hamartomas. If it is difficult to differentiate it from metastatic lung tumors in this case, minimally invasive surgery such as video-assisted thoracoscopic surgery should be performed to establish a definitive diagnosis.