Borrelia burgdorferi-associated lymphocytoma cutis simulating a primary cutaneous large B-cell lymphoma.

The distinction between primary cutaneous B-cell lymphoma and B-cell pseudolymphoma on a histologic basis may be difficult, particularly in some cases of Borrelia burgdorferi-associated lymphoid proliferations. We report two cases of B. burgdorferi-associated pseudolymphoma that showed a dense infiltrate with a predominance of large atypical B cells.