Endometriosis of the duplex appendix: A case report and review of the literature

Table 1 New classification of appendiceal anomalies

Number anomalies
Agenesis: Absence of appendix
Duplex appendix
Type A: Partial duplication with both appendices sharing a common base like ‘’ Y-shaped’’ on a single cecum
Type B: Complete duplication of the appendix on a single cecum
B1 avian type: Two appendices symmetrically placed on either side of the ileocecal valve
B2 tenia coli cecum type: One appendix arising from the usual site of the cecum and the other arising from the cecum along the tenia
B3 tenia coli hepatic flexure type: One appendix arising from the usual site of the cecum and the other arising from the hepatic flexure of the colon along the tenia
B4 tenia coli splenic flexure type: One appendix arising from the usual site of the cecum and the other arising from the splenic flexure of the colon along the tenia
Type C: Duplication of the cecum, each having its own appendix
Triplex appendix: Complete triplication of appendix on the cecum
Horseshoe appendix
With sagittal disposal: The bases of the appendix are along the tenia in sagittal direction
With frontal disposal: The bases of the appendix are not on the tenia

Data from these studies[4,10-13].

Table 2 Clinical features of patients with appendix endometriosis

Ref.	Year	Age	Symptoms	Previous history	Episode time	Hemoperitoneum
Uncu et al[25]	2008	45	Abdominal pain and nausea	Not described	The second day of menstruation	Yes
Akbulut et al[26]	2009	40	Lower right quadrant pain	Lower right abdominal pain before every menstrual period for 8 or 9 yr	The third day of menstruation	Not described
Uwaezuoke et al[23]	2013	29	Right iliac fossa pain	One-year history of recurrent lower abdominal pain	The second day of menstruation	Yes
Curbelo-Peña et al[24]	2015	39	Right iliac fossa pain	Not described	Be menstruating at the time	Yes
Shen et al[27]	2016	34	Right iliac fossa pain	Repeated abdominal pain associated with menstruation for several months	The second day of menstruation	Yes
St John et al[19]	2018	29	Migratory lower right quadrant pain	Not described	The second day of menstruation	Yes
Our case	2019	44	Migratory lower right quadrant pain	Eight-year history of repeated lower abdominal pain	Five days after the last menstrual period ended	Yes