Primary pulmonary diffuse large B cell lymphoma presenting as a left lower lobe mass: A case report and literature review

Introduction: Primary pulmonary diffuse large B cell lymphoma (PPDLBCL) is extremely rare neoplasm representing only 0.5–1% of primary pulmonary malignancies. Patients usually have non-specific clinical presentation and radiologic findings which makes it a challenging diagnosis. Case Report: We report the case of an 82-year-old man presenting with cough and unintentional weight loss. Chest computed tomography (CT) showed an infra-hilar left lower lobe mass with a mediastinal subcarinal lymph node. Tissue sampling by endobronchial ultrasound (EBUS) resulted in the diagnosis of primary pulmonary diffuse large B cell lymphoma. He was started on R-CHOP chemotherapy regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) and attained complete remission after 2 cycles. Conclusion: The findings from this case indicate that primary pulmonary diffuse large B cell lymphoma should be considered in the differential diagnosis of primary pulmonary masses.