A Rare Case of Sigmoid Colonic Duplication Causing Fistula to Caecum in an Adult Woman

Abstract

This is a case report about colonic duplication in a 43-year-old woman who presented with acute onset of pain in the lower abdomen and RIF, associated with constipation. She was treated as TB abdomen with partial intestinal obstruction. She was admitted repeatedly for similar complaints with additional nutritional problems developing later. CECT (whole abdomen) revealed a fistulous tract between the caecum and native sigmoid colon. Exploratory laparotomy was done. The finding was a retroperitoneal colonic duplication tract connecting the medial pole of caecum and native sigmoid colon. Limited right hemicolectomy including duplicated colon was done. Histopathology revealed normal colonic mucosa. The postoperative period was uneventful and improvement was seen on regular follow-up.

Introduction

Gastrointestinal tract duplication is a rare congenital anomaly that can occur anywhere along the alimentary tract. Approximately 80% of duplications occur inside the abdomen, while others occur in the chest. For digestive duplications, the ileum is the most common site (30%–35%) and the colon is the least common (7%–20%)1. The duplication can vary widely in size and shape; Cystic type accounts for more than 80% of incidence and tubular type makes up the rest¹.

Gastrointestinal tract duplication usually manifests during early childhood; and most patients (67%–80%) are diagnosed before the age of 2 years¹. Few patients remain asymptomatic until adulthood. Complications such as volvulus, bleeding, intussusception, perforation, and malignant transformation are typically the first clinical manifestations of gastrointestinal tract duplication¹. It is difficult to make a preoperative diagnosis. Surgery is usually performed to treat complications, and duplication is diagnosed intraoperatively in most of the cases.

This is a case of a 43-years-old woman who presented with repeated abdominal pain formerly treated as TB abdomen, and was diagnosed intra-operatively as tubular colonic duplication. The rarity of this case is reflected in three aspects: adult age at onset, retroperitoneal location, and tubular subtype. The most astonishing finding was fistulation between caecum and duplicated colon.

Case report

A 43-year-old Burmese woman from Myan-Aung came to our hospital to consult for her repeated attacks of abdominal pain, constipation, with loss of appetite and significant weight loss. She has had appendicectomy and right salpingectomy 20 years ago, normal GI endoscopy (OGDS + colonoscopy) 5 years ago, no abnormal finding on CECT (whole abdomen) 2 years ago (according to her history but no records available) with similar presentation. She was given anti -TB for 2 times (first time one and half years for TB intestine and next time for 6 months). At first, she was diagnosed as tuberculous abdomen which is common in our country. But investigations including GI endoscopy, did not support TB intestine nor fistula. So CECT with enema contrast was done, revealed diverticulum like outpouching from medial pole of caecum connecting to native sigmoid colon resembling a fistula tract. So, exploratory laparotomy was done. Intraoperatively, we didn’t find any abnormal connection between caecum and sigmoid colon, otherwise normal intraperitoneal structures. After thorough examination, hard globular mobile mass was felt in retroperitoneum, just above the pelvic brim. Retroperitoneum was opened and the mass was identified. Surprisingly it was a fecal mass within lumen of tubular structure which connected caecum and distal part of sigmoid colon (we have to appreciate our senior radiologist for her finding in computed tomogram). So, the entire tract was dissected and cut, and closure of the duplicated colon near the junction of the native sigmoid colon and limited right hemicolectomy was done. The patient’s postoperative period was uneventful and discharged from hospital after 7 days. On follow up, she had improved her symptoms and appetite, even gained weight.

Fig1: Specimen description of colonic duplication

Fig2: Picture of colonic duplication

Fig3: CT image of duplicated colon with enema contrast (yellow arrow – fistulation to caecum, green arrow – duplicated colon, red arrow – sigmoid side of duplicated colon)

Fig4: Histopathology of duplicated colon

Discussion

Gastrointestinal tract duplication is defined by three features: (1) encircling, well-formed smooth muscular layers, (2) a mucosal layer, and (3) association with some part of the gastrointestinal tract2. Communication between the anomalous and actual enteric lumens may or may not be present. The classification system for gastrointestinal tract duplications generally depends on the morphology and origin. McPherson and colleagues described their classification for colonic duplication in 1969 as follows: type I – simple cyst; type II – diverticula; and type III- tubular colonic duplication².

Several theories have been proposed to explain the formation of duplications, such as aberrant luminal recanalization, embryonic diverticula, a split notochord, partial twinning, and environmental factors3. But no single theory has perfectly explained all types of duplications; many different factors might be involved in the formation of gastrointestinal tract duplication. According to our review, gastrointestinal tract duplication in adults is rare and mostly described in case reports.

Adult patients’ symptoms were variable and nonspecific: acute or chronic abdominal pain, abdominal mass, bloody stools, bowel obstruction, diarrhoea, and weight loss^{2, 3}.The cause of this pain might be distension of the duplicated segment or compression of the adjacent organs. Gastric mucosa exists in about 50.8% of cystic duplications, so ectopic gastric mucosa ulcerations are common. This might explain hemorrhage as a symptom of digestive duplications⁴.

It is not easy to diagnose gastrointestinal tract duplication preoperatively, and misdiagnosis is common. In our patient, she might have earlier presentation, but failed to diagnose, she might encounter unnecessary operation and medications including anti-TB treatment. The frequently used diagnostic modalities, such as plain abdominal radiography and ultrasonography, provide limited information; a gas-filled structure (for example). Useful, feasible diagnostic methods are barium enema, CT, and colonoscopy. Any of these methods can determine communication between the anomalous and native enteric lumen. In our patient, colonoscopy was normal. CT is the most suitable diagnostic method for detecting digestive duplication, because it is easy to perform. In our patient, CT report gave us very useful tip to look for the tract, it was near missed. Cystic duplication can be mistaken for a cystic tumor of adjacent organ, in patients in whom luminal communication does not exist^1,2. Mostly the final diagnosis can only be made during exploratory laparotomy.

Surgery is the treatment of choice for symptomatic digestive duplications. For asymptomatic patients, the management strategy is controversial, however, most authors advocate surgical resection to prevent future complications and to eliminate the risk of adenocarcinoma1. Generally, resection of the duplication and adjacent intestine should be performed. In our case, we excised the colonic tubular duplication and right side of the colon and caecum. Only some small cystic duplications can be excised without colonic resection.

Colonic duplication can be associated with abnormalities of other organs¹. Sometimes a colo-vesical or recto-vaginal fistula can coexist1. Some of the patients had other congenital malformations. Physicians should assess patients and look for other malformations when digestive duplication is diagnosed. In our patient, there was no coexisting congenital anomaly.

Histopathology analysis typically reveals at least one outer muscular layer with an inner gastrointestinal mucosal lining1. The mucosal lining does not necessarily correspond to that of the adjacent normal intestine and may be comprised several different types of gastrointestinal mucosa. Some ectopic gastric mucosa in duplicated intestine can cause ulceration, and it may be the cause of first complaint like bleeding per rectum4. In our case, duplicated tract composed of normal mucosa of the colon, lamina propria is infiltrated by lymphocytes and plasma cells, with no feature of dysplasia and malignancy.

In conclusion, colonic duplication is a rare congenital anomaly which is usually diagnosed and treated during childhood. Some adults can harbor a silent duplication of bowel for many years until complications occur. The clinical presentation can include abdominal pain, an abdominal mass, bloody stools, bowel obstruction, and diarrhea. It is difficult to make the preoperative diagnosis of colonic duplication, and CT is the most suitable diagnostic method. The transverse colon is the most common site of colonic duplication, and surgery is advocated for both symptomatic and asymptomatic patients.

Sources

1. Xin Wu, Xiequn Xu, Binglu Li, Tubular colonic duplication in an adult; Case report and brief literature review; Journal of International Medical Research; First published online May 15, 2018.
2. Heiss K, Oldham KT, Colombani PM, Foglio RP, et al, Intestinal duplication, Surgery of infant and children : Scientific principles and practice, Philadelphia: Lipponcott – Raven, 1997, PP, 1265 – 1276.
3. Poligandla DS, Ngoyen LT, ST-Vil D, et al, Gastrointestinal duplications, Journal of paediatric surgery 2003, 38, 740 – 744.
4. C Fotiadis, M Genetzakis, Papandreous, EP Miscakas, E Agapitos, and GC Zografos, Colonic duplication in adult : Report of two cases presenting with rectal bleeding, World journal of gastroenterology, 2005 Aug 28, 11 (32) : 5072 – 5074.

Author Information

1. Myo Kyi, Consultant general surgeon, Pun Hlaing Hospital, Yangon, Myanmar.
2. San SanOo, Consultant radiologist, Pun Hlaing Hospital, Yangon, Myanmar.
3. Soe Naung Win, General surgeon, Pun Hlaing Hospital, Yangon, Myanmar.
4. Aung Moe Hlaing, Consultant general surgeon, Pun Hlaing Hospital, Yangon, Myanmar.
5. Kyaw Htay Lwin, Consultant general surgeon, Pun Hlaing Hospital, Yangon, Myanmar.
6. Win Myint, Professor, Department of General surgery, Pun Hlaing Hospital, Yangon, Myanmar.