BACKGROUND Splenosis is the ectopic autotrasplantation of splenic tissue that can follow trauma to the spleen or splenectomy and can occur anywhere in the peritoneal cavity or extraperitoneally. Splenosis can present incidentally without symptoms or with various symptoms depending on size and location. We describe a case of pelvic splenosis mimicking endometriosis in presentation. CASE REPORT A 37-year-old woman presented with dyspareunia, dysmenorrhea, and infertility >
10 years after a motor vehicle accident requiring splenectomy. Examination revealed suprapubic and uterine tenderness with no retrocervical tenderness or palpable nodularity. Imaging (ultrasound, computed tomography, and magnetic resonance) revealed multiple pelvic masses of unknown etiology concerning for endometriosis, malignancy, or splenosis. Diagnostic laparoscopy with surgical resection of the cul-de-sac masses was performed and pathology confirmed splenosis. The patient reported resolution of her complaints postoperatively, resulting in improved quality of life. CONCLUSIONS Although splenosis is a known condition that can occur after trauma, pelvic splenosis is less often described in the gynecologic literature, leading to diagnostic ambiguity with uterine and ovarian masses as well as endometriosis. We describe a case of splenosis presenting similarly to endometriosis with the aim to improve awareness and diagnostic accuracy of these confounding conditions.