An Unusual Case of Concurrent Herpes Simplex Virus Type 1 and Cytomegalovirus Encephalitis Complicated by Primary Central Nervous System Lymphoma as an Initial Presentation of Acquired Immunodeficiency Syndrome

Primary central nervous system lymphoma (PCNSL) is an uncommon brain tumor with a puzzling diagnosis. It has an incidence of seven cases per 100,000,000 people in the United States, which is further lower in immunocompromised patients. Cytomegalovirus (CMV) is a common cause of various malignancies, notably Burkitt’s lymphoma, nasopharyngeal carcinoma, Hodgkin’s lymphomas, and non-Hodgkin’s lymphomas (NHL) including PCNSL. Cases with PCNSL can vary in presentation with either focal or non-focal manifestations progressively worsening over a period that could last up to a few months. In this report, we discuss the case of a 39-year-old woman with a past medical history of bipolar disorder who presented with PCNSL as the initial presentation of acquired immunodeficiency syndrome (AIDS). This case report emphasizes the importance of a multidisciplinary team (MDT) approach for the interpretation as well as for correlating the laboratory and imaging results with clinical findings given the challenging diagnosis, to choose an appropriate management approach that is tailored to the patient's presentation.