Endometriosis Mimicking a Gynecologic Cancer Presentation

CASE DESCRIPTION: A 44-year-old premenopausal woman with acute abdominal pain, a pelvic mass detected on imaging and microcytic anemia was transferred to Gynecologic Oncology service due to clinical suspicion for pelvic neoplasm. Pelvic exam was notable for a palpable cervical mass, enlarged left adnexa, and nodularity of the parametrium. Computed Tomography demonstrated a 17.6X15.5X13.2cm, complex left adnexal mass with small volume ascites and omental thickening and nodularity, suggesting carcinomatosis. Patient underwent supracervical abdominal hysterectomy, bilateral salpingo-oophorectomy (BSO), omentectomy and radical excision of broad ligament pelvic mass. Intraoperative findings were consistent with large endometrioma. Pathology confirmed the large endometrioma in the broad ligament and endometriosis in the vagina. The ovaries, uterus, and fallopian tubes were negative for endometriosis. The uterine final pathology also demonstrated leiomyomas and an endometrial polyp. Three months after excision, the patient had no other symptoms of endometriosis. \n \nCONCLUSIONS: Endometriosis classically presents with symptoms of dysmenorrhea, dyspareunia, or infertility; however, up to 25% of patients remain asymptomatic. Only a few prior case reports have documented acute presentations of endometriosis. In this case, the presentation of fever, atypical laboratory values, pelvic exam findings and suspicious imaging (pelvic mass with omental thickening) led to a differential prioritizing malignancy. Patient underwent surgical resection, with intraoperative pathology consistent with an endometrioma. \n \nCLINICAL SIGNIFICANCE: This case of an atypical presentation of endometriosis in a previously asymptomatic patient mimicked a malignant process. Final pathological diagnoses of an endometrioma, endometriosis, leiomyomas, and an endometrial polyp highlight the importance of maintaining a broad differential that includes benign pathology and reliance on histopathological investigation.