The clinical implications of retroperitoneal endometriosis.

Over the past 10 years five patients with endometriosis involving only retroperitoneal structures in the pelvis without intraperitoneal involvement have been managed at the University of California-Los Angeles Hospital. These patients have presented difficult diagnostic and therapeutic problems. Moreover, this interesting but uncommon distribution of the disease has led to speculation concerning its pathogenesis. The substantial threat to the urinary tract and rectosigmoid colon is noted. Although a concurrent study at this hospital indicates a low incidence of endometriosis involving pelvic lymph nodes, it is quite apparent from the distribution of these instances of retroperitoneal involvement that its spread from the endometrium very likely takes place through pelvic lymphatics.