Primary Pulmonary Diffuse Large B-Cell Lymphoma on FDG PET/CT-MRI and DWI.

Primary pulmonary diffuse large B-cell lymphoma (PPDLBCL) directly arising from lung tissue is extremely rare. It may usually be misdiagnosed as inflammation including pulmonary tuberculosis, even lung cancer, because its clinical symptoms and signs are often nonspecific. The final diagnosis usually depends on lung biopsy. Herein, we report a case of PPDLBCL and review of diagnosis of this disease, particularly in radiology. A 44-year-old man presented with cough, sputum, and intermittent chest pain for 4 weeks. Multiple radiological examinations showed an irregular mass in the right upper lobe with ground-glass opacities around it and air-filled bronchi in the consolidation. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography-magnetic resonance imaging (MRI) detected positive FDG uptake, and diffusion-weighted imaging indicated abnormal hyperintension in the lesion. Inflammation was suspected, but malignance cannot be excluded. Finally, ultrasound-guided fine-needle aspiration cytology was performed for histological examination and definitive diagnosis yielded lymphomatous cells infiltration in the right upper lobe. This report emphasizes the significance of multimodality radiological examinations. Multimodality imaging contributes to proper diagnosis, staging, and management of lymphomas.