Gastrointestinal duplication, which may occur throughout the alimentary tract, is a rare congenital anomaly[1
]. More than 80% of the cases present before the age of 2 years, as acute abdomen or bowel obstruction[1,2
]. Most duplication is located in the ileum and presenting symptoms are bowel obstruction, intestinal bleeding and/or even perforation[3,4
]. Apart from ileal duplication, colonic duplication is a rare abnormality. A thorough review of the international literature since 1950 has revealed 83 cases of colonic duplication to date, and only 4%-18% of all gastrointestinal duplications have been reported in the cecum[5–7
Inclusion of the urogenital tract by an intestinal duplication has been reported in two cases[8,9
]. Duplication of the tubular colon and vermiform appendix causing hydronephrotic atrophic kidney in adults has not previously been reported.
Preoperative diagnosis of colon duplication is often difficult. Symptoms usually include abdominal pain, nausea and/or vomiting, palpable mass, weight loss, and bleeding, which often confuses colon duplication with other more common diagnoses. The pathogenesis of these lesions has not yet been well characterized. One of the most widely accepted theories is an abnormality of the embryonic gut that results in the formation of a diverticulum, a cyst, or twinning of a bowel segment[10
]. Environmental factors such as trauma or hypoxia during early fetal development have also been suggested to play a role[11
]. Although intestinal duplication is considered to be a benign lesion and mostly asymptomatic, they may result in significant morbidity and mortality if left untreated[12
]. Indications for surgical intervention often arise in an acute setting, in the form of complications. Specifically, patients with previously undetected duplication may present with bowel obstruction or severe gastrointestinal hemorrhage (i.e., ulcerating gastric mucosa within a duplication cyst)[5
]. If encountered incidentally, these lesions should be surgically addressed to avoid any future complication, including the possibility of malignant degeneration within the duplication cyst[5,12
Duplication of the vermiform appendix is extremely rare. It is found in only 1/25 000 patients (0.004%) operated on for acute appendicitis[13
]. The clinical presentation can vary depending on the location of the appendices in the colon. Cave and Wallbridge have classified the observed variants into several types: type A has incomplete duplication with both appendices having a common base; type B has complete duplication with the first appendix arising from its usual location at the confluence of the teniae coli, and the second appendix is located at various sites along the colon; and type C has complete duplication of the cecum, with each part having its own appendix[14,15
]. Our case was diagnosed as type B.
Although preoperative diagnosis has been made with the aid of radiological studies such as a barium enema, the majority of cases have been diagnosed at surgery or upon pathological examination. Barium enema studies are considered essential for the diagnosis of tubular colonic duplication, with opacification of two colons being the diagnostic sign. However, in certain cases, barium enema apparently does not show positive findings. A case has been reported in which a barium follow-through study established a complete diagnosis of duplication of the colon and terminal ileum. The findings were confirmed by laparotomy. Although the diagnosis of appendix duplication is a rarity, surgeons should be aware of the possibility, especially when clinical signs and symptoms point to appendicitis, although at laparotomy the appendix looks normal. Routine exploration for a second appendix is definitely not indicated because of its rarity and increased complication rate.
Although duplication of the alimentary tract is rare, the possibility of congenital lesions of the alimentary tract should not be overlooked, even in adults presenting with vague or no gastrointestinal symptoms.