An omphalomesenteric duct cyst, also known as a vitelline duct cyst, Meckel’s diverticulum, is a type of congenital abnormality that affects the small intestine. This condition occurs when a small portion of the embryonic tissue from which the intestine develops fails to disappear during fetal development. Instead, it forms a sac-like structure that protrudes from the wall of the small intestine, known as the Meckel’s diverticulum.
During fetal development, the yolk sac forms a connection between the embryo and the developing placenta. This connection is known as the omphalomesenteric duct, and it normally disappears by the 10th week of gestation. However, in some cases, the duct does not completely disappear, leaving a remnant that can develop into an omphalomesenteric duct cyst.
The omphalomesenteric duct cyst can be classified into three types based on their location and presentation:
- Meckel’s diverticulum: This type of cyst is connected to the ileum, which is the last part of the small intestine, and can cause symptoms such as abdominal pain, nausea, vomiting, and bleeding. Meckel’s diverticulum is the most common type of omphalomesenteric duct cyst.
- Umbilical cyst: This type of cyst is located at the site where the omphalomesenteric duct originally connected to the abdominal wall. It can present as a painless lump or a fluid-filled sac at the belly button, and can sometimes become infected.
- Mesenteric cyst: This type of cyst is located within the mesentery, which is the tissue that connects the intestine to the abdominal wall. It can cause symptoms such as abdominal pain, bloating, and constipation.
In addition to the three types of omphalomesenteric duct cysts, there are also different classifications based on the size and contents of the cyst. These include:
- Simple cyst: This type of cyst is filled with clear fluid and has a smooth surface. It is usually asymptomatic and does not require treatment.
- Complex cyst: This type of cyst is filled with a combination of fluid, mucus, and debris, and can have an irregular surface. It may cause symptoms and requires treatment.
- Hemorrhagic cyst: This type of cyst contains blood and may cause pain and discomfort. It may require treatment if it does not resolve on its own.
- Infected cyst: This type of cyst can occur when bacteria enter the cyst and cause an infection. It can cause symptoms such as redness, warmth, and pain in the affected area.
Causes
The following are causes of omphalomesenteric duct cysts:
- Congenital malformations: The most common cause of omphalomesenteric duct cysts is a congenital malformation, where the duct fails to close completely during embryonic development.
- Hereditary factors: Certain genetic conditions such as Gardner’s syndrome and Familial Adenomatous Polyposis (FAP) have been linked to the formation of omphalomesenteric duct cysts.
- Abnormalities in the vitelline duct: Sometimes the omphalomesenteric duct cysts may arise due to abnormalities in the vitelline duct, which is the structure that connects the yolk sac to the midgut.
- Umbilical cord infections: In some cases, infections in the umbilical cord may lead to the formation of omphalomesenteric duct cysts.
- Trauma to the umbilical region: Any injury or trauma to the umbilical region may cause omphalomesenteric duct cysts to form.
- Malignancy: In rare cases, omphalomesenteric duct cysts may be associated with malignancy, such as carcinoma of the colon.
- Hormonal imbalances: Hormonal imbalances during pregnancy may contribute to the development of omphalomesenteric duct cysts in the fetus.
- Polyhydramnios: The presence of excess amniotic fluid in the uterus has been linked to the development of omphalomesenteric duct cysts.
- Maternal diabetes: Maternal diabetes has been shown to increase the risk of omphalomesenteric duct cysts in the fetus.
- Fetal distress: Fetal distress during pregnancy may cause the omphalomesenteric duct to remain open, leading to the formation of cysts.
- Maternal drug use: Certain drugs taken during pregnancy, such as cocaine and heroin, have been linked to the development of omphalomesenteric duct cysts in the fetus.
- Maternal infections: Maternal infections during pregnancy, such as rubella and cytomegalovirus, have been associated with the formation of omphalomesenteric duct cysts in the fetus.
- Premature birth: Premature birth has been linked to an increased risk of omphalomesenteric duct cysts.
- Twin-to-twin transfusion syndrome: Twin-to-twin transfusion syndrome, where one twin receives more blood flow than the other, has been associated with the development of omphalomesenteric duct cysts in the affected twin.
- Umbilical hernia: An umbilical hernia, where a portion of the intestine protrudes through the umbilical ring, may be associated with omphalomesenteric duct cysts.
- Meckel’s diverticulum: Meckel’s diverticulum is a congenital abnormality of the small intestine that may lead to the formation of omphalomesenteric duct cysts.
- Inflammatory bowel disease: Inflammatory bowel disease, such as Crohn’s disease, has been associated with the development of omphalomesenteric duct cysts.
Symptoms
While some individuals with Meckel’s diverticulum may not experience any symptoms, others may experience a range of symptoms depending on the size and location of the cyst. Here are common symptoms associated with Omphalomesenteric duct cysts, along with explanations of their causes and potential treatments.
- Abdominal pain – One of the most common symptoms of Meckel’s diverticulum is abdominal pain, which is caused by the cyst pressing on the surrounding tissues. Treatment options for abdominal pain may include pain relievers or surgery.
- Diarrhea – Diarrhea is another common symptom of Meckel’s diverticulum, and is caused by inflammation of the intestinal lining. Treatment may include anti-inflammatory medications and/or changes in diet.
- Constipation – While diarrhea is a common symptom of Meckel’s diverticulum, some individuals may experience constipation instead. This can be caused by a blockage of the intestinal tract, which may require surgical intervention.
- Nausea and vomiting – Nausea and vomiting may occur in individuals with Meckel’s diverticulum due to the inflammation and irritation of the intestinal lining. Treatment options may include anti-nausea medications or surgery.
- Bleeding from the rectum – Bleeding from the rectum may occur in individuals with Meckel’s diverticulum due to inflammation or ulceration of the cyst. Treatment may include medication or surgery.
- Anemia – Anemia may occur in individuals with Meckel’s diverticulum due to chronic bleeding. Treatment may include iron supplements or blood transfusions.
- Fatigue – Fatigue is a common symptom of anemia and may be alleviated with iron supplements or blood transfusions.
- Weight loss – Weight loss may occur in individuals with Meckel’s diverticulum due to chronic diarrhea or other digestive symptoms. Treatment may include changes in diet or surgical intervention.
- Malnutrition – Malnutrition may occur in individuals with Meckel’s diverticulum due to chronic diarrhea or other digestive symptoms. Treatment may include changes in diet or surgical intervention.
- Intestinal obstruction – Intestinal obstruction may occur in individuals with Meckel’s diverticulum due to a blockage of the intestinal tract. Treatment options may include surgery or medication.
- Fever – Fever may occur in individuals with Meckel’s diverticulum due to inflammation and infection of the cyst. Treatment may include antibiotics or surgical intervention.
- Infection – Infection may occur in individuals with Meckel’s diverticulum due to bacteria or other microorganisms that enter the cyst. Treatment may include antibiotics or surgical intervention.
- Abdominal distention – Abdominal distention may occur in individuals with Meckel’s diverticulum due to the cyst pressing on the surrounding tissues. Treatment options may include surgery or medication.
- Peritonitis – Peritonitis is a serious complication that can occur in individuals with Meckel’s diverticulum due to rupture of the cyst. Treatment may include antibiotics and emergency surgical intervention.
- Appendicitis-like symptoms – Meckel’s diverticulum may present with symptoms that mimic appendicitis, including abdominal pain and tenderness, nausea and vomiting, and fever. Treatment may include surgical intervention.
Diagnosis
Diagnosis of omphalomesenteric duct cysts typically involves a combination of imaging studies and histopathological examination. Here are diagnostic tests and procedures that may be used to diagnose omphalomesenteric duct cysts:
- Ultrasound: Ultrasonography is often the first imaging modality used to evaluate a suspected omphalomesenteric duct cyst. Ultrasound can help visualize the location, size, and internal characteristics of the cyst.
- Computed tomography (CT): CT scan may be ordered to further evaluate the cyst and its relationship to surrounding structures. CT can provide more detailed information about the cyst’s size, shape, and location, and can also help identify any complications such as perforation, abscess formation, or obstruction.
- Magnetic resonance imaging (MRI): MRI may be used to better characterize the cyst and its relationship to adjacent organs. MRI can provide information on the cyst’s composition, fluid content, and potential for malignancy.
- Endoscopy: Endoscopic evaluation may be useful in cases where there is suspicion of an obstructing cyst or when biopsy is needed. Endoscopy can help determine the location and extent of the cyst and can also help evaluate for associated abnormalities such as gastrointestinal bleeding.
- Barium enema: Barium enema is a radiographic study that uses contrast material to evaluate the colon and rectum. It may be used to identify any abnormalities associated with the cyst such as bowel obstruction or colonic duplication.
- Upper gastrointestinal (GI) series: An upper GI series involves swallowing a contrast material to visualize the esophagus, stomach, and small intestine. It can help identify any obstruction or mass effect caused by the cyst.
- Radionuclide imaging: Radionuclide imaging involves the use of radioactive tracers to evaluate organ function and blood flow. This may be useful in identifying any associated malignancy or inflammatory changes.
- Angiography: Angiography is a radiographic study that uses contrast material to evaluate blood vessels. It may be used to evaluate any vascular abnormalities associated with the cyst.
- Blood tests: Blood tests may be ordered to evaluate for signs of infection or inflammation. Elevated white blood cell count, C-reactive protein, and erythrocyte sedimentation rate are common findings in patients with infected or inflamed cysts.
- Biopsy: Biopsy may be necessary to confirm the diagnosis and to evaluate for any malignancy. This is typically performed using a fine needle aspiration or core needle biopsy under imaging guidance.
- Histopathological examination: Histopathological examination of the cyst is often necessary to confirm the diagnosis and to evaluate for any malignant changes. This involves examining the tissue under a microscope to evaluate for any abnormal cells or structures.
- Cyst fluid analysis: Analysis of the fluid within the cyst may be helpful in determining its composition and potential for malignancy. Cyst fluid can be obtained either by fine needle aspiration or during surgical excision.
- Laparoscopy: Laparoscopy is a minimally invasive surgical technique that allows direct visualization of the abdominal cavity. It may be used to evaluate the cyst and its relationship to surrounding structures and to perform a biopsy or excision.
Treatment
Observation For patients who are asymptomatic, simple observation may be the preferred treatment option. Many people with omphalomesenteric duct cysts may never experience any symptoms, and their condition may be discovered incidentally during imaging studies for other medical reasons. In such cases, no intervention may be necessary, and the patient can be monitored periodically for any changes or progression of the cyst. Regular follow-up imaging studies may be recommended to ensure that the cyst does not grow or become symptomatic over time.
Medications
- Antibiotics If a patient with an omphalomesenteric duct cyst develops an infection, antibiotics may be prescribed to treat the infection and prevent further complications. Infection of an omphalomesenteric duct cyst is known as Meckel’s diverticulitis and can be caused by a variety of bacteria, including Escherichia coli, Klebsiella, and Streptococcus. Symptoms of Meckel’s diverticulitis may include abdominal pain, fever, nausea, and vomiting. Antibiotics may be administered orally or intravenously, depending on the severity of the infection.
- Antibiotics: Antibiotics are often used to treat infected OMCs or those associated with peritonitis. The choice of antibiotics depends on the organism causing the infection and the sensitivity of the organism to different antibiotics. The duration of treatment usually ranges from 7 to 14 days.
- Proton pump inhibitors: Proton pump inhibitors (PPIs) are a class of drugs used to reduce the production of stomach acid. They are often used to treat symptoms of gastroesophageal reflux disease (GERD), but they can also be used to treat symptoms associated with OMCs. PPIs are usually prescribed for a short period (1-2 months) to reduce acid secretion and prevent further damage to the cyst.
- H2 blockers: H2 blockers are another class of drugs that reduce the production of stomach acid. They are less potent than PPIs but can be used as an alternative or in combination with PPIs. H2 blockers are usually prescribed for a short period (1-2 months) to reduce acid secretion and prevent further damage to the cyst.
- Analgesics: Analgesics are pain-relieving drugs that can be used to alleviate abdominal pain associated with OMCs. The choice of analgesic depends on the severity of pain and the patient’s medical history. Commonly used analgesics include nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids.
- Antiemetics: Anti-emetic drugs are used to control nausea and vomiting associated with OMCs. These drugs are usually prescribed for a short period to relieve symptoms and prevent further damage to the cyst. Commonly used antiemetics include metoclopramide and ondansetron.
- Corticosteroids: Corticosteroids are a class of drugs that have anti-inflammatory properties. They are sometimes used to treat OMCs associated with inflammation or as an alternative to surgical intervention in patients who cannot undergo surgery. Corticosteroids are usually prescribed for a short period (1-2 weeks) to reduce inflammation and relieve symptoms.
- Octreotide: Octreotide is a synthetic analogue of somatostatin, a hormone that inhibits the secretion of growth hormone and other hormones. Octreotide can be used to treat OMCs associated with diarrhea, particularly those caused by hormonal imbalances. Octreotide is usually prescribed for a short period (1-2 weeks) to reduce hormone secretion and relieve symptoms.
Surgery
For patients with symptomatic or complicated omphalomesenteric duct cysts, surgical intervention may be necessary. Surgery is also indicated if the cyst is suspected to be cancerous or if there is a risk of bowel obstruction. The type of surgical procedure used will depend on the size, location, and characteristics of the cyst, as well as the age and overall health of the patient. Some surgical options include:
- Laparoscopic resection – Laparoscopic resection is a minimally invasive surgical procedure that involves making small incisions in the abdomen and using a laparoscope to remove the cyst. This approach is preferred in cases where the cyst is small and easily accessible. The advantage of laparoscopic resection is that it results in less scarring, shorter hospital stays, and faster recovery times compared to traditional open surgery.
- Open resection – Open resection is a more invasive surgical procedure that involves making a larger incision in the abdomen to access the cyst. This approach is preferred in cases where the cyst is large, located in a difficult-to-reach area, or associated with other complications. The advantage of open resection is that it allows for more thorough examination and removal of the cyst, and may be necessary in cases where laparoscopic resection is not feasible.
- Bowel resection – In some cases, the cyst may be located in close proximity to the small intestine, and surgical removal of the cyst may require removal of a portion of the small intestine. This procedure, known as bowel resection, may be necessary if the cyst is causing a blockage or if there is a risk of bowel perforation. Bowel resection may be performed using either laparoscopic or open surgical techniques.
- Symptomatic treatment – If surgery is not feasible or if the patient is not a suitable candidate for surgery, symptomatic treatment may be recommended to manage any symptoms associated with the cyst. This may include pain management
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