Neoadjuvant Chemoradiotherapy Treatment for a Classic Biphasic Pulmonary Blastoma with High PD-L1 Expression.

Pulmonary blastomas are rare malignant tumors, comprising only 0.25-0.5% of all malignant lung neoplasms. The prognosis of pulmonary blastoma is very poor, with an overall five-year survival of 16%. No standard treatment has been defined for unresectable disease. We present the case of a 25-year-old woman with unresectable locally advanced classic biphasic pulmonary blastoma (CBPB) successfully treated with neodjuvant chemoradiotherapy based on two chemotherapy induction cycles of cisplatin plus etoposide, followed by concurrent weekly cisplatin to 50.4 Gy radiotherapy treatment. The patient had a significant reduction in tumor size, allowing for complete resection by pneumonectomy. Molecular study for epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK), proto-oncogene receptor tyrosine kinase (ROS1) and rearranged during transfection (RET) rearrangements, and programmed death ligand 1 (PD-L1) expression was performed in the pre-treatment tumor sample. Our patient presented a high expression (>90% of tumor cells) of PD-L1. To our knowledge, this is the first report of PD-L1 expression in CBPB. This could lead to new treatment options based on new immunotherapy agents blocking the PD-1/PD-L1 pathway for this rare disease with poor prognosis.