Pneumatosis cystoides intestinalis is characterised by the presence of multiple gas-filled cysts in the submucosa and/or gastrointestinal subserosa of the small intestine. It is a subtype of pneumatosis with specific features, which can occur anywhere along the gastrointestinal tract, including the colon, rectum, and mesentery. When associated with the colon it is known as pneumatosis cystoides coli. It is one of the non-surgical cause of pneumoperitoneum in neonates ¹⁴.

Epidemiology

Pneumatosis cystoides intestinalis is an uncommon entity found in all age groups. It occurs most commonly in adults in their 5th-8th decades and has an estimated incidence of ~0.03% ^11,12. This could actually be an underestimation, as most cases are asymptomatic.

Associations

About 15% of the cases have no known causes, while 85% of the cases are associated with other conditions, including ¹¹:

• inflammatory bowel disease ¹²

  • Crohn disease

  • ulcerative colitis ^9,10

• necrotising enterocolitis ¹³

• sigmoid volvulus ¹²

• COPD ¹³

• progressive systemic sclerosis ¹³

• gastrointestinal hypermobility

Pathology

When the cysts rupture it may cause “benign pneumoperitoneum” as there is an absence of peritoneal irritation.

Radiographic features

Depending on the degree of gastrointestinal involvement, pneumatosis cystoides intestinalis may be diffuse, segmental, or localised.

It is typically characterised by well-circumscribed cysts/”bubbles” within the walls of the hollow gastrointestinal viscera. These cysts are surrounded by regular and non-inflamed mucosa. A small volume pneumoperitoneum may be present.

If diffuse, it may appear to occupy large areas of the abdomen with a honeycomb pattern that appears similar to that of interstitial lung disease.

History and etymology

Pneumatosis cystoides intestinalis was first decribed by DuVernoi in 1783. The disease was further subcategorised by Koss in 1952 ¹¹.

See also

• intramural bowel gas