Occam's Razor Need Not Apply: A Case of Concurrent Cryptococcal Meningitis and Primary Central Nervous System Lymphoma in an Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome Patient

Abstract

A 28-year-old man with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) (CD4 cells 4/1%) was diagnosed and treated for cryptococcal meningitis (CM) 3 weeks before admission with a 14-day course of amphotericin and flucytosine and subsequently discharged on oral fluconazole. However, surveillance of cerebrospinal fluid (CSF) cultures collected before discharge later turned positive for Cryptococcus neoformans and he was called back for evaluation. On admission, the patient reported headache, diplopia, and overall malaise. A head computed tomography showed new enhancing mass lesions in the left and right caudate nuclei with vasogenic edema (Figure 1). Repeat lumbar puncture showed a high opening pressure of 35 mmH2O and C neoformans detected by antigen and CSF culture. He was resumed on amphotericin and flucytosine induction therapy for presumed relapsed CM with possible cryptococcoma. A magnetic resonance imaging (MRI) of the brain was obtained and showed 2 different lesions with increased density, restricted diffusion, and low T2 signal relative to normal brain parenchyma, which were most concerning for central nervous system (CNS) lymphoma or toxoplasmosis and less concerning for cryptococcoma by radiographic appearance (Figure 2). Further CSF studies ruled out toxoplasmosis but showed positive Epstein-Barr virus DNA polymerase chain reaction, again concerning for CNS lymphoma. A brain biopsy could not be obtained due to the location of lesions. Therefore, MRI spectroscopy was performed and showed an increase in the size of both masses suggestive of malignancy (Figure 3) and an elevated choline peak with decreased N-acetylaspartate (NAA) peak, consistent with high-grade CNS lymphoma (Figure 4). The patient was started on antiretroviral therapy and steroids with initial improvement in symptoms, but he subsequently developed acute neurologic decompensation requiring emergent whole brain radiation therapy, which was complicated by hemodynamic instability and hypothermia. He eventually stabilized and was discharged on oral fluconazole and to complete radiation as an outpatient followed by high-dose methotrexate therapy (Figure 5).