digestive pneumatosis

Digital cases

 Case 226: Parietal pneumatosis in neonatal necrotic enterocolitis

Definition: Pneumatosis intestinalis is characterized by the accumulation of gas in the gastrointestinal wall.

The histopathologic diagnosis is easily made on resection specimens in which the presence of submucosal or subserosal empty spaces lined by histiocytes and giant cells presents little diagnostic dilemma.

In biopsy material, though, the diagnosis is more challenging, as giant cells and histiocytes can be interpreted as granulomatous inflammation indicative of other conditions such as infection or Crohn disease.

Synopsis

 pseudo-polyps
 raised mucosal folds
 submucosal cystic spaces lined by giant cells
 giant cells lining a rounded or cleftlike space
 pseudolipomatosis
 round empty spaces in the submucosa resembling fat
 nonspecific findings

• variable inflammation
• eosinophilia
• mild gland disarray
• vascular ectasia
• edema
• mild melanosis coli

Differential diagnosis

 granulomatous inflammation

• granulomatous colitis
  • Crohn disease

Etiology

 acquired immunodeficiency syndrome (AIDS)
 ischemic colitis
 cytomegalovirus colitis

Localization

 intestinal pneumatosis
 colonic pneumatosis

Synopsis

 cryptitis
 crypt abscesses
 mucosal chronic inflammation
 mucosal granulomas
 crypt dilation
 partial crypt rupture
 intramucosal cysts
 clusters of small gas cysts in the lamina propria.

Etiology

 neonatal necrotizing enterocolitis (NNEC)
 anaerobial bacterial enterocolitis
 high intraluminal pressure

• cystic fibrosis (16702447, 9530294)
• chronic digestive obstruction
  • adhesional obstruction (16420873)
  • motility disorders (12.5%)
    • sclerodermy (15981628)
    • primary intestinal pseudo-obstruction (16271330)
    • acute colonic pseudo-obstruction (Ogilvie syndrome) (14650951)

Associations

 healthy children (22%)
 organ and bone marrow transplant (22%)
 decompensated congenital heart disease (12.5%)

 gastroschisis (9%)
 short bowel syndrome (6%)

 most common events immediately preceding

• noninfectious colitis (32%)
• acute enteric infection or toxin (27%)
• bowel ischemia (20%)
• gastrointestinal dysmotility (17%)
• graft versus host disease colitis

See also

 Pneumatosis

• hepatic pneumatosis
• cerebral pneumatosis

References

 Koreishi A, Lauwers GY, Misdraji J. Pneumatosis intestinalis: a challenging biopsy diagnosis. Am J Surg Pathol. 2007 Oct;31(10):1469-75. PMID: 17895747

 Pieterse AS, Leong AS, Rowland R. The mucosal changes and pathogenesis of pneumatosis cystoides intestinalis. Hum Pathol. 1985 Jul;16(7):683-8. PMID: 4007844