3. Classification: extrinsic versus intrinsic

Endometriosis can infiltrate the ureter intrinsically or extrinsically. When extrinsic – 80–90% of such cases – the endometriosis infiltrates the adventitia and/ or submucosa. When intrinsic (the remainder of cases), the disease infiltrates the mucosa and submucosa and may present as ureteral stenosis [5, 7].
