EBV+ B-cell polymorphic lymphoproliferative disorder of the lip in a patient with advanced chronic lymphocytic leukemia

Introduction: Polymorphic B-cell lymphoproliferative disorders (B-LPDs) are a rare, morphologically heterogeneous, and diagnostically challenging group of neoplasms that occur in the setting of immunosuppression. Associated lesions are almost uniformly Epstein-Barr virus-positive (EBV+) and can cause destructive masses that may mimic more aggressive lymphomas. Clinical outcomes are highly variable, ranging from resolution with withdrawal of immunosuppression to fatal dissemination of disease.
Clinical case: A 77-year-old white male with a history of advanced chronic lymphocytic leukemia (CLL) presented with a six-week history of a tender sore on his right lower lip. He had previously been treated with acyclovir without improvement. Physical exam revealed a 1 cm firm tender nodule with overlying crusted erosion on the right lower lip. A deep saucerization biopsy was performed which showed a dense lymphoplasmacytic infiltrate composed primarily of plasmacytoid cells extending into the subcutis. In-situ hybridization for EBV (EBER) was diffusely positive, while CD30, CD20, and Pax-5 immunostains showed only rare clusters of positive cells. The kappa/lambda ratio was 1:10, consistent with lambda light chain restriction. IGH clonality assay failed to detect a monoclonal population. On the basis of these results, a diagnosis of EBV+ polymorphic B-LPD was favored. Unfortunately, the patient expired a few weeks after presentation as a result of complications from his CLL.
Conclusion: We report a rare case of cutaneous EBV+ polymorphic B-LPD. Prompt and accurate diagnosis of this entity is important to avoid pursuit of unnecessarily aggressive therapies, prompt workup for undiagnosed immunodeficiency, and minimize the risk of fatal progression.