Abstract
A 33-year-old woman, para 1001, had pain in the inner right thigh and proximal right leg weakness. At surgery a locally invasive, fibrotic lesion was found encircling the right ureter, right internal iliac vein and obturator nerve. It extended to the periosteum of the ilium. The lesion was dissected successfully without damage to vital structures, and endometriosis was confirmed histologically.