Pulmonary blastoma: a clinicopathologic study of 3 cases and review of literature

Pulmonary blastoma (PB) is a rare biphasic neoplasm. Surgery is the preferred treatment with no consensus on the role of other therapies. We report the clinicopathologic features of PB in three patients. We reviewed the medical records of patients diagnosed with PB at Jackson Memorial Hospital, Miami, FL, since 2009–2012. The mean age at diagnosis was 53 years; two were male and both were heavy smokers. At diagnosis, all cases were symptomatic; two were stage IV with metastatic disease. Two out of three patients were treated with absolute curative surgical resection and both patients had no evidence of disease. Patient with stage IV and resection relapsed in 28 months, received chemotherapy and then radiation without response and died after 33 months. The other surgical patient has no evidence of disease at the end of this study. The patient with unresectable disease received chemotherapy alone attaining partial response. Pathologically, all cases showed biphasic morphology composed of epithelial and spindle cell stroma with mesenchymal differentiation. Immunohistochemical analysis revealed positivity in all cases for thyroid transcription factor, keratin, and epithelial membrane antigen in the epithelial component and negative in the mesenchymal component. In conclusion, surgery was the most beneficial intervention. Chemotherapy has shown mixed responses which is consistent with the literature. Targeted therapies should be explored as additional treatment options in PB.