Unique radiological features of two cases of primary pulmonary diffuse large B-cell lymphoma

Radiographic infiltration of the lungs by malignant lymphoma is often observed, with a reported frequency of approximately 25%. On the other hand, primary pulmonary lymphoma (PPL) is very rare. According to previous reports, PPL was observed in only 3% of patients with extranodal lymphoma, and in less than 1% of patients with non-Hodgkin's lymphoma. Most cases of PPL (58%–87%) are marginal zone lymphomas of the mucosa-associated lymphoid tissue (MALT) type.1 However, primary lung diffuse large B-cell lymphoma (DLBCL) is rare (10%).2 Here we present two cases of primary lung DLBCL displaying unique imaging. ### Case 1 A 56-year-old woman complaining of dyspnoea and fever was admitted to our hospital. Consolidation in the bilateral upper fields on chest radiological examination and multiple pulmonary nodules on CT were the only abnormalities detected by radiography (Figure 1A). Upper and lower endoscopy showed no evidence of gastrointestinal cancer. A trans-bronchial lung biopsy (TBLB) was subsequently performed for histopathological analysis. Haematoxylin and eosin staining of tissue sections showed diffuse and monotonous proliferation of large round cells, in the form of sheets within interstitial lung tissue (Figure 1B). Immunohistochemical staining demonstrated that the …