Atypical Borrelia garinii infection in an immunocompromised patient mimicking high-grade lymphoma.

We report an atypical Borrelia garinii infection in a patient who was immunocompromised. It was first suspected as a transformation of follicular lymphoma into high-grade lymphoma. Spirochetes were directly observed on a peripheral blood smear and the diagnosis was confirmed using molecular methods. The clinical presentation and the diagnosis are unique and contrast with the cases described in the literature in patients who are immunocompromised.