Granulomatous Pneumocystis jiroveci pneumonia in a patient with diffuse large B-cell lymphoma: case report and review of the literature.

Here we report a case of diffuse large B-cell lymphoma who developed granulomatous Pneumocystis jiroveci pneumonia (PJP) after rituximab and combination chemotherapy. The infection presented as a solitary pulmonary nodule (SPN) instead of the commonly seen diffuse ground-glass infiltrates. The diagnosis was made by wedge resection of the nodule. Both the CD4+ lymphocyte count and immunoglobulin level were low. A literature search revealed 14 granulomatous PJP patients with hematological neoplasms, including the present case, which was the first with diffuse large B-cell lymphoma and the only patient receiving rituximab before PJP development. In addition to our report, only one case had previously presented with an SPN. Our experience suggests that granulomatous PJP should be considered a possible etiology when immunocompromised patients develop fever and SPNs.