As the clinical presentation, radiographic appearances and differential diagnosis vary with the location of involvement these are discussed sequentially by region (see below)
Smooth muscle atrophy and fibrosis are thought to be the chief underlying mechanism which leads to luminal dilatation, reduced motility and reduced sphincter tone.
The esophagus is affected in 80% of scleroderma cases. Symptoms include heartburn and dysphagia.
- dilatation of distal two-thirds of the esophagus 1
- apparent shortening of length due to fibrosis
- dysmotility of lower esophagus (normal peristalsis above aortic arch)
- gastro-esophageal reflux due to reduced sphincter tone
- air-fluid level in esophagus when supine (CT)
The differential diagnosis includes other causes of a dilated esophagus (see achalasia pattern) and includes:
- achalasia: distal segment of narrowing is less than 3.5cm
- central and peripheral neuropathy
- esophageal malignancy
- esophageal stricture
Gastric involvement is relatively uncommon but can result in delayed gastric emptying with or without gastric dilatation. Gastric vascular antral ectasia (dilated submucosal capillaries), often known as watermelon stomach, may also occur.
The small bowel is affected in more than 60% of scleroderma patients, the duodenum most frequently. Patients may be asymptomatic or may present with bloating or malabsorption due to bacterial overgrowth.
- luminal dilatation (can be massive)
- reduced peristalsis / delayed contrast transit
- mucosal folds appear relatively normal despite dilatation
- hidebound bowel sign (crowding of valvulae conniventes): thought to be pathognomonic of scleroderma
- accordion sign: well seen evenly spaced mucosal folds in duodenum
- sacculation (antimesenteric border, focal dilatations, pseudo-diverticula)
The large bowel is affected in ~40% of patients and may cause constipation or diarrhea. Reduced anal sphincter tone can result in fecal incontinence.
- loss of haustration
- colonic dilatation
- reduced colonic transit time
- 1. Bhalla M, Silver RM, Shepard JA et-al. Chest CT in patients with scleroderma: prevalence of asymptomatic esophageal dilatation and mediastinal lymphadenopathy. AJR Am J Roentgenol. 1993;161 (2): 269-72. AJR Am J Roentgenol (abstract) - Pubmed citation
- 2. Pickhardt PJ. The "hide-bound" bowel sign. Radiology. 1999;213 (3): 837-8. Radiology (full text) - Pubmed citation
- 3. Katzka DA, Reynolds JC, Saul SH et-al. Barrett's metaplasia and adenocarcinoma of the esophagus in scleroderma. Am. J. Med. 1987;82 (1): 46-52. Pubmed citation