Splenunculus mimicking splenomegaly in a patient with synchronous herpes simplex 1 viremia and myelosuppression

Abstract Splenunculus, or congenital accessory spleen, is a benign anatomical variation, and is rarely of clinical consideration in routine clinical practice. We describe a patient who presented with synchronous herpes simplex 1 viraemia and myelosuppression, with a splenunculus mimicking splenomegaly, and we discuss the implications on clinical practice, investigations, and management.