Extra-Pelvic Endometriosis

Common types and locations include abdominal wall endometriosis, which often develops at surgical scar sites, particularly following cesarean sections. This scar endometriosis typically presents as a painful, cyclical mass at the incision site that becomes more symptomatic during menstruation. It affects approximately 0.03-0.45% of women who have undergone cesarean delivery, though actual numbers may be higher due to underdiagnosis.

Thoracic endometriosis represents another significant category, affecting the chest cavity, including the diaphragm, pleural surfaces, and lung tissue. This form predominantly affects the right side of the chest, but occasionally the left side. One of the most common symptoms of diaphragmatic endometriosis is cyclical shoulder tip pain that can radiate to the neck. Less commonly, thoracic endometriosis can cause catamenial pneumothorax (a collapsed lung during menstruation), chest pain coinciding with menstrual periods, and, in rare cases, coughing up blood during menstruation.

Diagnosing extrapelvic endometriosis requires high clinical suspicion, especially in women with cyclical symptoms occurring at surgical sites or in distant organs. MRI provides excellent soft tissue contrast and is the imaging modality of choice for evaluating suspected extrapelvic endometriosis.  Ultrasound can be useful for superficial abdominal wall lesions, particularly when performed during menstruation, when lesions may be more prominent. CT scans may be employed when evaluating thoracic or abdominal organ involvement. However, a definitive diagnosis ultimately requires histopathological confirmation of endometrial glands and stroma within the affected tissue.