Necrotic herpes simplex lymphadenitis imitating Richter's transformation in a patient with chronic lymphocytic leukemia - A case report.

Richter Transformation (RT) is the phenomenon of progression from Chronic Lymphocytic Leukemia (CLL) into an aggressive Large-Cell Lymphoma and is typically characterized by diffuse lymphadenopathy combined with the classical "B symptoms". While rare, other causes of sudden onset diffuse lymphadenopathy in patients with CLL can occur; one of the rarest being necrotic herpes simplex lymphadenitis. We report a case that presented similarly to Richter Transformation including PET-CT scan findings consistent with RT but was histologically proven to be necrotic herpes simplex lymphadenitis. We identified less than 20 reported cases of this phenomenon in English language literature. Our patient was successfully treated with appropriate antiviral therapy due to timely recognition of the correct disease process. Our case reinforces the importance of maintaining diagnostic suspicion when approaching sudden onset lymphadenitis in this patient population.