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Gastrointestinal system

Peritoneum and peritoneal cavity disorders



Upper gastrointestinal tract disorders

Cleft lip and palate

Congenital diaphragmatic hernia

Esophageal web

Tracheoesophageal fistula

Pyloric stenosis



Oral candidiasis

Ludwig angina

Aphthous ulcers

Temporomandibular joint dysfunction

Dental abscess

Gingivitis and periodontitis

Dental caries disease

Oral cancer

Warthin tumor

Mallory-Weiss syndrome

Boerhaave syndrome


Eosinophilic esophagitis (NORD)

Plummer-Vinson syndrome

Zenker diverticulum

Diffuse esophageal spasm

Gastroesophageal reflux disease (GERD)

Barrett esophagus

Esophageal cancer


Gastric dumping syndrome

Peptic ulcer


Cyclic vomiting syndrome


Gastric cancer

Lower gastrointestinal tract disorders


Imperforate anus


Meckel diverticulum

Intestinal atresia

Hirschsprung disease

Intestinal malrotation

Necrotizing enterocolitis


Tropical sprue

Small bowel bacterial overgrowth syndrome

Celiac disease

Short bowel syndrome (NORD)

Lactose intolerance

Whipple's disease

Protein losing enteropathy

Microscopic colitis

Crohn disease

Ulcerative colitis

Bowel obstruction

Intestinal adhesions


Gallstone ileus

Abdominal hernias

Femoral hernia

Inguinal hernia

Small bowel ischemia and infarction

Ischemic colitis

Familial adenomatous polyposis

Peutz-Jeghers syndrome

Gardner syndrome

Juvenile polyposis syndrome

Colorectal polyps

Colorectal cancer

Carcinoid syndrome

Irritable bowel syndrome


Diverticulosis and diverticulitis


Anal fissure

Anal fistula


Rectal prolapse

Liver, gallbladder and pancreas disorders

Crigler-Najjar syndrome

Biliary atresia

Gilbert's syndrome

Dubin-Johnson syndrome

Rotor syndrome



Portal hypertension

Hepatic encephalopathy


Wilson disease

Budd-Chiari syndrome

Non-alcoholic fatty liver disease

Cholestatic liver disease

Hepatocellular adenoma

Autoimmune hepatitis

Alcohol-induced liver disease

Alpha 1-antitrypsin deficiency

Primary biliary cirrhosis

Primary sclerosing cholangitis


Neonatal hepatitis

Reye syndrome

Benign liver tumors

Hepatocellular carcinoma


Biliary colic

Acute cholecystitis

Ascending cholangitis

Chronic cholecystitis

Gallstone ileus

Gallbladder cancer


Acute pancreatitis

Pancreatic pseudocyst

Chronic pancreatitis

Pancreatic cancer

Pancreatic neuroendocrine neoplasms

Zollinger-Ellison syndrome

Gastrointestinal system pathology review

Congenital gastrointestinal disorders: Pathology review

Esophageal disorders: Pathology review

GERD, peptic ulcers, gastritis, and stomach cancer: Pathology review

Inflammatory bowel disease: Pathology review

Malabsorption syndromes: Pathology review

Diverticular disease: Pathology review

Appendicitis: Pathology review

Gastrointestinal bleeding: Pathology review

Colorectal polyps and cancer: Pathology review

Neuroendocrine tumors of the gastrointestinal system: Pathology review

Pancreatitis: Pathology review

Gallbladder disorders: Pathology review

Jaundice: Pathology review

Viral hepatitis: Pathology review

Cirrhosis: Pathology review




0 / 6 complete

USMLE® Step 1 questions

0 / 1 complete

High Yield Notes

11 pages



of complete


USMLE® Step 1 style questions USMLE

of complete

A 26-year-old woman, G2P1, comes to the emergency department in active labor. She has not received prenatal care during this pregnancy. A 3500g boy is delivered by an uncomplicated vaginal delivery. His temperature is 36.7°C (98°F), pulse is 120/min, respirations are 40/min, and blood pressure is 85/60 mmHg. Physical examination shows low-set ears, micrognathia and clenched fingers. Abdominal examination shows a midline non-reducible mass covered by a whitish membrane. Which of the following is the most likely cause of this patient's abdominal findings?  

External References

First Aid








Omphalocele p. 366


Content Reviewers

Rishi Desai, MD, MPH


Tanner Marshall, MS

With an omphalocele, omphalo- refers to the naval, also known as the bellybutton—or more formally the umbilicus—which is the attachment site of the umbilical cord, and -cele relates to hernia or swelling.

Omphalocele, therefore, is when some of the bowels herniate out into the umbilical cord.

During the fourth week of fetal development, the embryo starts to change shape from a flat, three-layer disc to something more shaped like a cylinder, a process called embryonic folding.

In the horizontal plane, the two lateral folds eventually come together and close off at the midline, except for at the umbilicus, where the umbilical cord connects the fetus to the placenta.

This folding allows for the formation of the gut within the abdominal cavity.

During around the sixth week of development, the liver and intestines grow really quickly, and because the abdominal cavity’s still pretty small, there’s limited space, which causes the midgut to herniate through the umbilical ring into the umbilical cord, and this happens normally.

At about week 10, though, the abdominal cavity typically has grown enough to allow the midgut to come back from the umbilical cord.

With omphalocele, the midgut—along with potentially other organs from the abdominal cavity—fail to return back to the abdominal cavity, and therefore stay in the umbilical cord all the way through fetal development and even after birth.

Now, since the intestines and potentially other organs aren’t meant to be in the umbilical cord, there can be complications like the abdominal cavity not growing to its normal size, as well as pinched blood vessels and loss of blood flow to an organ.

So with an omphalocele, after birth the abdominal organs protrude out of the body, but are contained within the umbilical cord, meaning the organs are sealed by a peritoneal layer.


An omphalocele is an abdominal wall birth defect in which the intestines, liver, and occasionally other organs remain outside of the abdomen in a sac, as a result of a defect in the development of the muscles of the abdominal wall. The sac, which is formed from an outpouching of the peritoneum, protrudes in the midline through the umbilicus.

Omphalocele shouldn't be confused with another condition called gastroschisis, which also involves the herniation of abdominal contents out of the abdominal cavity. Unlike in omphalocele, herniated bowels in gastroschisis lack a peritoneal layer covering.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Prenatal and postnatal management of omphalocele" Prenatal Diagnosis (2008)
  6. "Early development of the abdominal wall, stomach and heart from 7 to 12 weeks of gestation: a longitudinal ultrasound study" Ultrasound in Obstetrics and Gynecology (1995)

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