Atypical Neurotoxoplasmosis in an Hiv-Negative Patient: A Case Report

Neurotoxoplasmosis (NTX) typically occurs in patients with uncontrolled human immunodeficiency virus (HIV) infection and is rare in seronegative individuals, even under other forms of immunosuppression. In such cases, it presents in a distinct and atypical manner, and diagnosis is challenging. Classically, it presents with headache, confusion, fever, and focal neurological deficit, but may be pauci-symptomatic. Diagnosis is based on clinical, serologic, and radiologic criteria. Doubtful cases require lesion biopsy for confirmation. To present and discuss the diagnostic challenge of atypical NTX. A 65-year-old woman with a history of pulmonary non-Hodgkin lymphoma in remission for 20 years and currently on the 6th cycle of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) for newly diagnosed diffuse large B-cell leg-type cutaneous lymphoma. She presented with sudden onset paresis and paresthesia of the left upper limb, with a T2 and FLAIR hyperintense lesion and perilesional edema on brain MRI, suggestive of fungal infection or secondary lymphoma implant. CSF was normal with negative serologies, and she had partial response to dexamethasone. To define the etiology, a lesion biopsy was performed. In the immediate postoperative period, she developed non-convulsive status epilepticus and septic shock. Follow-up CT showed findings suggestive of a meningovascular process. Two days later, biopsy results unequivocally confirmed NTX and appropriate treatment was initiated, but she died the following day. NTX in HIV-negative immunosuppressed patients is rare and more commonly associated with transplant recipients or patients with hematologic, ocular, or brain neoplasms. It usually occurs by reactivation of latent infection and is atypical and severe. There is no classic association with chemotherapy, but R-CHOP suppresses T-cell-mediated immunity, which is responsible for keeping Toxoplasma under control, and may predispose to reactivation. The meningovascular pattern is a rare and poorly predictable complication after biopsy and is often fatal. Our case illustrates the diagnostic and management challenges of NTX in complex patients, and its severity even in paucisymptomatic presentations. The literature lacks epidemiologic data in this population, and further studies are needed to better understand its relationship with immunosuppression.