Listeria monocytogenes septicemia and meningoencephalitis associated with relapsed and refractory follicular lymphoma.

Listeria monocytogenes is a foodborne pathogen which causes life-threatening septicemia and meningoencephalitis. Defective cell-mediated immunity is a well-known risk factor of human listeriosis. We herein present a case of 64-year-old Japanese woman with relapsed and refractory follicular lymphoma (FL). Salvage chemoimmunotherapy with cyclophosphamide, vincristine, prednisolone, and obinutuzumab was followed by obinutuzumab maintenance therapy, when a follow-up computed tomography scan revealed recurrent lymphadenopathy. One month later, the patient presented with fever and headache. L. monocytogenes was recovered from an anaerobic blood culture. Cerebrospinal fluid analysis confirmed the presence of meningoencephalitis. The invasive listeriosis was successfully treated with meropenem for three weeks. There were several predisposing factors of invasive listeriosis in our case. Cell-mediated immunity was severely impaired by prior cytotoxic chemotherapy and low-dose prednisolone. Use of a proton pump inhibitor facilitated entry of the microorganism into the host. Under these circumstances, patients with relapsed and refractory FL are susceptible to invasive listeriosis even if they avoid high-level contaminated food products. Of note, physical examination at initial presentation detected periorbital vesiculopustular eruptions with surrounding erythema. Cutaneous listeriosis is a rare but recurrent manifestation which might be occasionally overlooked. Skin eruptions should be carefully examined for early diagnosis.