A rare case of primary pulmonary diffuse large B cell lymphoma with CD5 positive expression.

Primary pulmonary diffuse large B-cell lymphoma (PPDLBCL) is extremely rare. Its clinical symptoms and signs are nonspe cific, and imaging features also have not yet been well-defined. Further description is important for the diagnosis and treatment of PPDLBCL. Herein, we reported a case of a patient who suffered from bilateral chest pain and dyspnea. Computed tomography (CT) of chest demonstrated bilateral lung mass, consolidations and reverse halo sign, while consolidations and reverse halo sign are uncommon according to previous reports. Tissue samples were taken by CT guided needle biopsy. The histological samples showed PPDLBCL. This case was special in view of positive expression of CD5. After the case was treated by cyclophosphamide pirarubicin vindesine dexamethasone (CHOP) chemotherapy for six courses, her clinical symptoms were partially alleviated, while CT showed progression disease. This case report highlights different imaging features and characteristics of molecular biology, and reviews study progress of PPDLBCL.