Disseminated Marginal Zone Lymphoma in a Patient with Lyme Neuroborreliosis: A Case Report.

Introduction: Lyme borreliosis has been associated with lymphoma, particularly cutaneous lymphomas. The literature is conflicted regarding the effect of antibiotic therapy in cutaneous marginal zone lymphomas (MZLs) in individuals with Lyme borreliosis. We present a patient diagnosed with Lyme neuroborreliosis (LNB) and disseminated MZL.

Case presentation: A 67-year-old man was seen due to 6 weeks of neuropathic pain with nightly worsening, headache, and 5 kg weight loss. Two weeks prior to symptom debut, he had a tick bite in the left groin, no subsequent rash. A lumbar puncture revealed mononuclear pleocytosis and elevated CSF protein. The patient was admitted and started on ceftriaxone. The Borrelia burgdorferi intrathecal test showed intrathecally produced Borrelia antibodies, and treatment was changed to doxycycline with a total treatment duration of 21 days. A PET/CT revealed enlarged lymph nodes with increased FDG uptake. On pathological examination, the CSF showed 62% clonal B cells - compatible with low-grade B-cell lymphoma. Examination of bone marrow and an inguinal lymph node confirmed disseminated MZL. A control lumbar puncture 8 weeks later showed declining pleocytosis and clonal B cells. At last follow-up 20 months later, he was still asymptomatic and had not required antineoplastic treatment.

Conclusion: To our knowledge, this is the first published case of LNB with non-cutaneous B-cell lymphoma treated and remitting on antibiotics alone. Antibiotic treatment for Borrelia-positive lymphomas has yet to be investigated with high-evidence study designs, so clinicians are encouraged to publish both positive and negative findings relevant to this. We believe this case brings new perspectives to future diagnosis and treatment of lymphomas in patients with verified Lyme borreliosis.