Abdominal Cysts and Duplications

Abstract

Many intra-abdominal cystic masses are being detected by prenatal imaging. They are often asymptomatic but those that cause symptoms usually do so in the first year or two of life. Symptoms are usually the result of compression or obstruction due to enlargement of the cyst as it gradually fills with fluid, or bleeding and ulceration due to gastric or pancreatic lining of the cyst. Cysts can arise from solid or hollow organs and various imaging modalities can help to distinguish the specific site of origin. Enteric duplication cysts are sometimes associated with intestinal atresias whereas tubular colonic or rectal duplications are commonly associated with genitourinary malformations. Optimal treatment usually involves complete resection of the cyst; but in some situations asymptomatic cysts detected prenatally can be observed clinically and radiographically.

Appendices

Summary Points

Intestinal duplications are extremely rare, only about 1 in every 4,500 autopsy cases.

The majority of duplications are found in the jejuno-ileal region (44%); other areas more rare-stomach 7%, duodenum 5%, colon 15%, rectal 5%, thoracic 4%, cervical very rare.

Synchronous abdominal and thoracic cysts/duplications may occur (approximately 15%).

Many cysts and duplications are asymptomatic and are discovered by prenatal imaging.

Diagnosis can be made by radiographic imaging but often duplications are discovered intra-operatively.

Treatment goal is complete removal of cyst/duplication for gastric and small bowel duplications due to risk of bleeding. May need to consider mucosal stripping and/or marsupialization for longer duplications.

Prognosis – overall prognosis is excellent, especially for isolated, small duplication cysts. Malignant degeneration of duplication cysts is a rare but serious complication.

Editor’s Comment

Ovarian cysts identified antenatally or at birth are almost always the result of antenatal torsion. They are usually asymptomatic and can be safely observed but many will fail to resolve by serial US and should be removed. The contralateral ovary should be inspected, however oophoropexy is unnecessary and probably ineffective. Simple ovarian cysts in older girls should be excised if they are large, growing or symptomatic. The inner lining can usually be stripped cleanly, preserving the parenchyma and the ovarian capsule, where the ova reside. Simple unroofing or marsupialization results in a high recurrence rate and should only be done if stripping is impossible due to hemorrhage or inflammation.

Nearly every true cyst can be treated by stripping its epithelial lining, though complete excision is often easier and less morbid. By definition, enteric duplication cysts have a mucosal lining but removal of just the lining is a challenge. It is usually safer to simply excise it. Since they almost always arise from the mesenteric side of the bowel wall, this usually entails bowel resection. This approach is not used for long tubular duplications or duodenal duplications, which should be stripped, if possible, or the common wall between the cyst and the adjacent bowel lumen can be obliterated to create a single lumen. This is not ideal in that it essentially creates a diverticulum but it might be the only alternative to an extensive and dangerous bowel resection (Whipple procedure, esophagectomy).

A simple liver cyst should be observed and will usually remain stable, unless it represents an echinococcal cyst or abscess. Simple pancreatic cysts are rare and can be excised if located in the tail but should probably be treated like a pseudocyst if located in the head or neck of the pancreas. Splenic cysts must always be completely excised by partial or total splenectomy, as the lining is never able to be stripped or obliterated. Some have tried using sclerotherapy, the argon beam coagulator to destroy the epithelium, or marsupialization, but each of these techniques is associated with an unacceptable recurrence rate.

Omental cysts can torse, bleed or rupture, in some cases mimicking appendicitis. They can be simply excised by laparoscopic partial omentectomy. Mesenteric cysts are more difficult to deal with as they can insinuate extensively within the mesentery and retroperitoneum. Ideally they should be excised, but this might not be feasible, in which case the only option is partial excision and marsupialization.

Most abdominal cysts and duplications can and should be approached laparoscopically, at least at first. Preoperative planning must include high-resolution three-dimensional imaging such as a CT or MRI. The goal should be to effectively eradicate the cyst, either by excision, epithelial stripping, or marsupialization, in that order of preference, but to minimize postoperative discomfort and scarring.

Differential Diagnosis

• Mixed solid/cystic tumors

• Choledochal cysts

• Splenic cysts

• Genitourinary dilatation

• Pancreatic cysts/pseudocysts

• Dilatation of normal structures (hydroureter)

• Traumatic hematoma

• Ovarian cysts/tumors

Diagnostic Studies

• Plain radiographs

• Abdominal US

• Upper GI contrast study

• Contrast enema

• CT

• MRI

• ERCP/MRCP

Parental Preparation

• Possible bowel resection

• Possible stoma

• Risk of recurrence (lymphangioma)

• Possible oophorectomy or salpingectomy

Preoperative Preparation

• IV hydration

• Informed consent

• Foley catheter if pelvic cyst

Technical Points

Laparoscopy vs. open

Leave cyst intact if suspect malignancy

Bowel resection if cyst/duplication involves mesentery

Mucosal stripping if unable to remove entire cyst/duplication

Connect colonic duplications distally to normal colon

Exploration for synchronous duplications