Abstract
INTRODUCTION: Accessory Spleen (AS) is a very rare entity and usually near the spleen's hilum and in the tail of the pancreas. Pelvis reported as an atypical and a rare localization. AS may be formed during embryonic life, they rise from the left side of the dorsal mesogastrium as a result of imperfect fusion of separate splenic masses. PRESENTATION OF CASE: We report a case of an AS presenting as an left adnexal mass in a middle-aged woman. Transvaginal ultrasonography and magnetic resonance imaging (MRI) revealed a left adnexial mass. Laparatomy was performed, and histological examination revealed that resected mass was splenic tissue. DISCUSSION: An AS is an incidental finding of no clinical significance in most patients. AS are generally determined during radiological investigations or during open or laparoscopic surgeries. When, the AS settle in the adnexal area; the differential diagnosis could include the causes of adnexal masses like enlarged lymph nodes, subserous fibroid, ovarian tumors, organized hematoma, tuboovarian abscess. CONCLUSION: Althought pelvic accessory spleen is a rare condition, should be considered in the differential diagnosis of adnexal masses.