CASE OF THE SEASON - ADULT PULMONARY BLASTOMA

Pulmonary blastoma is a rare tumor of the lung consisting of immature mesenchyma and epithelial structures that can mimic the structure of the embryonic lung. In this article, we report a case of pulmonary blastoma occurred in an adult individual. We review the literature concerning this rare neoplasm that includes less than one hundred cases reported. We also describe the pathologic features of this disease which is microscopically divided in two classes: 1) lesions composed solely of malignant gland of embryonic appearance (WDFA: Well-Differentiated Fetal Adenocarcinomas), and 2) lesions with biphasic appearance, containing both neoplastic glands and either adult sarcomatous or embryonic mesenchyme. The adult pulmonary blastomas are considered as an entity distinct from chidhood blastomas. This condition may be frequently asymptomatic; if symptomatic, it shows the same clinical picture of a mass in the lung impinging on bronchi or pleura; the most usual symptoms include cough, hemoptysis, and chest pain. Chest radiography typically shows a peripheral or central lung opacity without preference for any lobe. The prognosis is poor, due to the high incidence of metastasis. Histologic class and clinical findings can be of prognostic value in pulmonary blastoma. We believe that an early diagnosis is essential: in our case, this allowed a complete resection of the tumor and the patient is still alive without recurrence 3 years after the surgical treatment.