[A case of pulmonary blastoma composed of histological features of both pulmonary blastoma and pulmonary endodermal tumor resembling fetal lung].

A case of pulmonary blastoma in a 71-year-old male was reported. Chest X-ray and CT scan showed a well demarcated mass lesion in the apical segment of the right lung. A polypoid tumor was detected in the apical branch of the right bronchus by bronchoscopy. The biopsy confirmed the diagnosis of pulmonary blastoma. The patient underwent a right upper lobectomy with lymph nodes dissection on Jan. 26, 1990. The resected tumor was really composed of two parts: a main tumor in the lung parenchyma and polypoid one protruding into the bronchus from the main tumor. The polypoid tumor exhibited typical features of pulmonary blastoma with both carcinomatous and sarcomatous components. The histology of the main tumor was identical to pulmonary endodermal tumor resembling fetal lung (PET). The metastases in the excised lymph nodes consisted entirely of carcinomatous elements. The patient died of brain stem metastasis a year after his operation. The present case, with typical pulmonary blastoma and PET present in the same tumor, supports the idea that pulmonary blastoma and PET belong to the same group neoplasma.