Sonographic Differential Diagnosis in Deep Infiltrating Endometriosis: The Bowel

Table 1

Characteristics of all cases of Figure 1 at a glance.

Organ	Sonographic diagnosis			Differential diagnosis
	Case number	US suspect	Appearance	US suspect	Differences
Rectum	#1, #2, #3, #4,; #5, #6, #7, #8	Rectal endometriosis (confirmed diagnosis)	Lesions can present with different shapes, but they have always an anechoic appearance without posterior enhancement, can encroach the bowel lumen and their limits can be digitiform (#1), irregular (#2, #3), or smooth (#4, #5); very often the “sliding sign” is negative	Rectal polyp (see case #18 of Figure 4); Rectal diverticula (see cases #16 and #17 of Figure 3); Rectal cancer (see cases #19 and #20 of Figure 4)	(i) Age; (ii) Family history; (iii) Rectal bleeding; (iv) Recta polyps and cancer grow from inside outwards while endometriosis starts from the serosa and encroaches the bowel; (v) Only advanced rectal cancer can invade the serosa and pararectal tissue