[Case report of pulmonary biphasic tumor with unusual follow-up].

Background: Pulmonary blastoma, a rare primary lung malignancy is subdivided in 3 categories: well-differentiated fetal adenocarcinoma (WDFA), classic biphasic pulmonary blastoma (CBPB) and pleuropulmonary blastoma (PPB). Classic pulmonary blastoma is composed of a mixture of immature epithelial and mesenchymal tissue resembling fetal lung tissue.

Case Report: We described a case of a 48-year-old male, cigarette smoker, who presented with left thoracic pain and hemoptysis for 2 months. Chest radiography showed a well-delimited, homogeneous 4cm mass in the left lung periphery. Bronchoscopic examination revealed left endobronchial bleeding. Computed tomography of the chest revealed a tumor shadow measuring 7cm in the left upper lobe and bilateral nodules with no lymphadenopathy. A systemic evaluation demonstrated no metastatic lesion. Patient underwent a left upper lobectomy. The diagnosis of CBPB was affirmed on anatomopathology of the tumor resection. Immunohistochemical studies showed that tumor cells were positive for vimentin, desmin, actin, Pan Cytokeratin and TTF-1. The final diagnosis was BPB classified as pathological T3N0M0 and no adjuvant treatment was associated. The patient showed good objective response with no evidence of disease recurrence still in 5 years surgery resection.

Conclusion: This case reiterates the importance of pathomorphological or immunohistochemical features in diagnosis of BPB.