RESUMO
Pulmonary blastoma (PB) is an uncommon primary lung malignancy. This neoplasm was first described by Barrett and Barnard in 1945. The tumor is composed of immature epithelial and mesenchymal tissues which may recapitulate early embryological lung development. Under the microscope, the globular component resembles immature bronchus and connective tissue as seen in embryonic lung. More than one hundred cases have been reported in the literature. PB is more frequent in older people and in males and tends to affect blacks at younger ages. Symptomatology varies from asymptomatic to symptoms of a non-specific pulmonary disease. Cough, hemoptysis, dyspnea, chest pain, respiratory distress, fever, anorexia and weight loss are the most common presenting features. The most common roentgenologic pattern is a well-demarcated peripheral lesion, encapsulated by compression or atelectatic lung tissue, although in some cases there is a tendency to lobulation and cavitation. The size of the mass varies from a small peripheral nodule to a mass occupying the entire lobe or hemithorax. The treatment of choice has been surgical excision, radiation and, in selected cases, a combination of chemotherapy with radiation. The prognosis of this malignancy is poor; overall five-year survival is approximately 16 percent. No correlation has been established between histopathologic criteria and survival. The factors that indicate poor prognosis are tumor recurrence, metastasis at initial presentation, tumor size over 5 cm and lymph node metastasis. Liver, central nervous system and bones are the most frequent location of distant metastases. A rare case is presented of a pulmonary blastoma with an upper lip metastasis occurring in a paraplegic male. Diagnosis was confirmed by autopsy findings.(ABSTRACT TRUNCATED AT 250 WORDS)
