Concurrent Non Hodgkin lymphoma and Pneumocystis jiroveci pneumonia in an AIDS patient: a diagnostic challenge

Abstract

Lymphoma and Pneumocystis jiroveci infection are well-described entities in Human immunodeficiency/Acquired immunodeficiency syndrome (HIV/AIDS) patients. They are both AIDS defining diseases according to the World Health Organization (WHO). Although they are known to occur frequently in this patient population, concurrent B cell lymphoma and Pneumocystis jiroveci pneumonia, has not been reported in the literature. We describe the case of an HIV/AIDS patient with no history of anti-retroviral therapy, previously diagnosed lymphoma or treatment with chemotherapy, who was diagnosed with HIV during a recent incarceration, during which he developed fever, shortness of breath and fatigue. Due to the complex nature of his clinical presentation, a pulmonary lobectomy was performed. Grossly, there was an ill-defined, friable, necrotic mass. Microscopically, there was an exudate consistent with Pneumocystis jiroveci and atypical lymphoid cells scattered throughout the necrotic tissue. Immunohistochemical stains demonstrated positivity of these lymphoid cells with CD20, PAX5, BCL2 and MUM1 with a diagnosis of large B cell lymphoma, activated type. A case of concurrent Pneumocystis and B cell lymphoma developing in an HIV/AIDS patient with no history of chemotherapy has not been reported to our knowledge.