Incidental Abdominal Wall Mass Diagnosed As Endometriosis: A Rare Finding in an Increasingly Common Pathology

Endometriosis is becoming a well-discussed topic in the medical field of women's health, but rare and uncommon pathologic cases such as abdominal wall endometriosis are often overlooked in a patient's differential diagnoses. This is likely due to the need for greater awareness of its diverse clinical presentations, its impact on patient well-being, and the limitations in clinical suspicion, imaging accuracy, and treatment approaches. Although abdominal wall endometriosis is increasingly diagnosed, healthcare providers remain hesitant to prioritize it - along with endometriosis in general - as a primary diagnosis. In this paper, we discuss a case of a 51-year-old perimenopausal G2P2 female who presented to the emergency department with chief complaint of heavy vaginal bleeding for the past week. Physical exam revealed mild tenderness in the suprapubic area with notable diffuse masses, but was otherwise normal with no mass felt on abdominal palpation. Initial lab results at admission showed hemoglobin at a critical value of 5.4, for which the patient was immediately started on red blood cell transfusion. A transvaginal pelvic ultrasound resulted in fibroid uterus, normal sonographic appearance of endometrial complex, and nonvisualization of either ovary. Given the patient's extensive reproductive history and the need to rule out common causes of abnormal uterine bleeding, such as fibroids, adenomyosis, endometrial hyperplasia, and malignancy, the decision was made to proceed with a supracervical subtotal hysterectomy with bilateral salpingo-oophorectomy. During the procedure, an incidental abdominal mass was discovered and partially resected to allow for further investigation. After being reviewed by pathology, a rare finding was revealed, that is, abdominal wall endometriosis. The emphasis of this case is to describe the rarity of abdominal wall endometriosis, the clinical significance of early recognition by including abdominal wall endometriosis in the differential list, and to explore the different diagnostic and treatment modalities available, and all with the goal of providing further awareness for clinicians to consider abdominal wall endometriosis as a diagnosis in women premenarche, perimenopause, and postmenopause.