A Case of Estimated Primary Ectopic Multiple Thymoma of the Lung with Primary Lung Cancer

Abstract

Thymoma arisen in the lung is extremely rare and only few cases have been reported so far. Primary intrapulmonary thymoma is difficult to be differentiated from other pulmonary tumors based on imaging studies. Surgical resection of the tumor with pathological diagnosis is useful for making the definite diagnosis. This paper deals with a case of a patient who developed pulmonary adenocarcinoma while she had been followed for multiple nodules : which were eventually diagnosed as thymomas after upper lobectomy of the right lung.

A 71-year-old woman who had been followed for bilateral multiple pulmonary nodules underwent resection with biopsy of a nodule 20 years earlier which was diagnosed as benign nodule. An irregular shaped shadow situating in the right upper lobe and showing an increasing tendency was detected and was diagnosed as pulmonary adenocarcinoma by CT-guided lung biopsy. We performed thoracoscopic right upper lobectomy and pathologically diagnosed as moderately differentiated adenocarcinoma pT1bN0M0 Stage I A2. Two solid nodules were present in the right upper lobe which were diagnosed as intrapulmonary thymoma (type A). Its morphological characteristics were same as those seen in the former specimen taken 20 years earlier. There were no tumor shadows suggestive of thymoma in the thymus, so that we diagnosed the case as multiple thymomas which might have arisen in the lung.