Discussion
Alimentary tract duplications are spherical or tubular structures, one
of the rare developmental anomalies that can occur anywhere in the
intestinal tract from the tongue to the anal canal. Most of the
duplications are found in the pediatric population and involve the small
bowel. On the other hand, colonic duplication cysts represent 6.8% of
gastrointestinal duplication cysts (6). The definition
was proposed that it is covered by flat muscles, has a gastrointestinal
mucosa on the inner surface, and is in close contact with the part of
the gastrointestinal tract (1). However, there are
some cases reported as gastrointestinal duplication even if all three
conditions are not met. This case met all of the above three items.
The shape of the alimentary tract duplications is roughly classified
into tubular and spherical. The colon as a whole has many tubular
overlapping intestines, but the rectum has many spheres. In the rectum,
it is said to occur frequently in the posterior wall.
The first symptoms of rectal duplication are often constipation and
abdominal distension, probably because of the exclusion of the
intestinal tract. In some cases, it escapes outside the anus(7, 8). Overlapping ureters, bladder malformations,
fistulas with the urethral system, and pyuria may be present(7). There are also cases of multiple intestinal
infections and bleeding. The epithelium of duplication cyst is usually
the colonic mucosa (9), but in rare cases, ectopic
gastric mucosa may be present. It causes ulcers and bleeding.
Surgical resection is the main treatment of choice(5). If the main intestine and the wall of the
duplication tract share a muscular layer, a method of removing only the
mucosa may be used. There is also a report that malignancy is observed
when asymptomatic progresses despite the presence of ectopic gastric
mucosa (10). We chose robot-assisted rectal resection
as the surgical procedure.