Abstract
INTRODUCTION: An accessory spleen (AS), a common condition, is usually located in the hilar region of the spleen. ASs are not often large; however, after splenectomy, the initially inactive AS may become reactive and hypertrophic. Therefore, an AS can be misdiagnosed as a neoplastic tumor and removed unnecessarily. An undiagnosed abdominal mass located in the spleen site in a patient who has had a splenectomy must be managed carefully. Computed tomography (CT) scanning and magnetic resonance imaging (MRI) may provide useful information for the diagnosis, preventing unnecessary surgery. CASE PRESENTATION: Herein, we report the case of a 38-year-old female with an enlargement of AS after splenectomy that was misdiagnosed as a primary tumor of the pancreas and managed by a nonessential surgery. CONCLUSION: An AS should be added to the differential diagnosis of a pancreatic tail tumor for patients with prior splenectomy in order to avoid nonessential surgery to ensure the patient's safety.