[Cytomegalovirus meningoencephalitis in a diffuse large B-cell lymphoma patient undergoing salvage chemotherapy].

A 63-year-old woman was admitted to our hospital to receive a fourth course of modified rituximab-ESHAP chemotherapy for relapsed primary breast diffuse large B-cell lymphoma. She developed hemophagocytic lymphohistiocytosis (HLH) 20 days after admission. Polymerase chain reaction (PCR) detected cytomegalovirus (CMV) DNA in her peripheral blood; therefore, she was diagnosed with CMV-associated HLH and consequently treated with foscarnet (FCN). Her general condition and pancytopenia soon improved, and the antiviral drug was stopped for 1 week. However, she suddenly became disoriented 10 days later, and this condition rapidly worsened. Cerebrospinal fluid (CSF) examination revealed an elevated white blood cell count with lymphocytic predominance and a high CMV DNA load, prompting a final diagnosis of CMV meningoencephalitis. We began intravenous combination therapy with FCN and ganciclovir (GCV), and her conscious state gradually improved. CMV DNA sequencing did not reveal drug resistance associated with mutations, and intravenous GCV was stopped for 1 week. FCN treatment was then continued until CMV DNA was no longer detected in her CSF samples via PCR. CMV meningoencephalitis is a rare neurological infection complicated with hematological malignancy in non-transplant patients and can be serious and life-threatening with a high mortality rate. This infection requires a differential diagnosis of consciousness impairment that develops in a patient with lymphoid malignancy during chemotherapy.