diverticulum

Small pouch or sac formed in the wall of a major organ, usually the esophagus, small intestine, or large intestine (the most frequent site of problems). In the large intestine, feces pushed into a pouch can make it bulge out from the colon wall, a condition known as diverticulosis, which has no symptoms. In the more serious condition called diverticulitis, those sacs become inflamed, causing pain and tenderness, chills, and sometimes fever. Mild cases need only bed rest and antibiotics. In severe cases, perforation or rupture of the colon wall at the diverticulum can cause peritonitis. Rupture may require colostomy. Meckel diverticulum, a congenital malformation of the upper intestine that causes bleeding and inflammation, may require surgical removal.

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A diverticulum (plural: diverticula) is medical term for an outpouching of a hollow (or a fluid filled) structure in the body. It usually implies that the structure is not normally present, i.e. pathological. However, embryologically, some normal structures begin development as a diverticulum arising from another structure.

An alphabetical listing of some frequently encountered diverticula follows:

Pathological

• Bladder diverticulum: Balloon-like growths on the bladder commonly associated with a chronic outflow obstruction, such as benign prostatic hypertrophy in older males. Usually found in pairs on opposite sides of the bladder, bladder diverticula are often surgically removed to prevent infection, rupture, or even cancer.
• Cardiac diverticulum: A very rare congenital malformation of the heart that is usually benign
• Colonic diverticula: These can become infected (see diverticulitis) and can perforate, requiring surgery
• Diverticulum of Kummerall: unusual nomenclature, in that focal dilatations of a blood vessel are properly referred to as aneurysms
• Duodenal & Jejunal diverticul(um|a): congenital lesions, may be a source of bacterial overgrowth, may perforate and may result in abscesses
• Epiphrenic diverticulum: due to dysfunction of the lower esophageal sphincter, as in achalasia
• Killian-Jamieson diverticulum
• Meckel's diverticulum: a persistent portion of the omphalomesenteric duct present in 2% of the population
• Rokitansky-Aschoff sinuses: in the gallbladder due to chronic cholecystitis
• Traction esophageal diverticulum: due to scarring from mediastinal or pulmonary tuberculosis
• Urethral diverticulum: congenital in males, post-infectious in females
• Zenker's diverticulum: a diverticulum of the mucosa of the pharynx affecting adults

Embryological

• The Kidneys, originally diverticula in the development of the urinary and reproductive organs
• The lungs, originally diverticula forming off of the ventral foregut.
• The thymus appears in the form of two flask-shape diverticula, which arise from the third branchial pouch (pharyngeal pouch)of the endoderm.

Footnotes