Cystic fibrosis (abdominal manifestations)

Abdominal manifestations in cystic fibrosis (CF) are common, varied and nearly all organ systems can be affected, and it should be remembered that only 39% of patients with cystic fibrosis have pulmonary symptoms as their sole complaint ¹. Not only that, but 7% of cystic fibrosis patients do not present until adulthood. 

This article focuses on abdominal manifestations of cystic fibrosis. For general discussion of cystic fibrosis, and a discussion of its other manifestations, please refer to:

• cystic fibrosis (parent article)

  • pulmonary manifestations of cystic fibrosis

  • head and neck manifestations of cystic fibrosis

  • musculoskeletal manifestations of cystic fibrosis

Pancreatic manifestations

The pancreas is the most commonly involved abdominal organ in cystic fibrosis. Exocrine gland insufficiency affects 85-90% of all cystic fibrosis patients and results from inspissated secretions leading to proximal duct obstruction with subsequent acinar disruption and replacement by fibrous tissue and fat.

Endocrine dysfunction occurs in ~40% (range 30-50%) of cystic fibrosis patients ^ref:

• fatty replacement

  • most common manifestation of the pancreas

  • can progress to complete pancreatic lipomatosis

  • mean age is 17 years ⁶

• acute pancreatitis: occurs in patients with residual pancreatic exocrine function

• pancreatic calcifications: occur in 7% of patients

• pancreatic cysts: typically microscopic 3 mm diameter ^ref

• pancreatic cystosis

• pancreatic duct stricture

Hepatobiliary manifestations

Liver parenchymal disease

• up to 72% of adult cystic fibrosis patients will develop liver disease ⁶

• focal biliary cirrhosis (pathognomonic for cystic fibrosis and present in 78%): focal portal fibrosis and cholestasis; thickened hyperechoic periportal tissue on ultrasound (>2 mm thickness)

• up to 12% progress to multilobular cirrhosis ⁵, but the development of hepatocellular carcinoma (HCC) is unusual

• 1-8% progress to portal hypertension

• hepatic steatosis (23-67% ⁶; seen in 30% of cystic fibrosis patients at biopsy, 30-50% at imaging and 60% at autopsy ²)

• pathophysiology is multifactorial

Biliary tree

• gallstones: 12-24% of cystic fibrosis patients

• sclerosing cholangitis

• intrahepatic ductal strictures are seen in 100% of patients with cystic fibrosis and liver disease and may correspond histologically to focal biliary fibrosis seen in 78% of patients >24 years old

• microgallbladder: seen in up to 30% of cystic fibrosis patients at autopsy ³

Gastrointestinal manifestations

• gastro-esophageal reflux and associated complications such as Barrett esophagus: thought to be secondary to chronic cough, hyperinflation, and diaphragmatic depression

• gastric and duodenal ulcerations: likely related to impaired bicarbonate secretion

• distal intestinal obstruction syndrome (DIOS)

• intussusception: typically ileocolic and may result from adherent fecal residue or enlarged lymphoid follicles ⁴; a chronically distended appendix may be the lead point

• despite the common distention of the appendix by inspissated secretions, the reported prevalence of acute appendicitis in cystic fibrosis patients is lower than that in the general population

• colon: often abnormal, with proximal colonic wall thickening, pericolonic fat proliferation, and mesenteric fat infiltration

• pneumatosis intestinalis: confined to the colon and typically coincides with the development of obstructive lung disease

• rectal mucosal prolapse: typically in young children in whom a diagnosis of cystic fibrosis has not yet been made or young adults that are noncompliant with treatment

• gastrointestinal tract malignancies, of which colorectal carcinoma is most common

Renal manifestations

• renal stones: symptomatic stones are twice as common in cystic fibrosis patients (~4.5%) compared to the general population (2%) ⁶

• nephrotic syndrome from secondary amyloidosis (poor prognostic sign) ⁶