Golgi-to-ER transport

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65a

CASE 65

History

A 45-year-old female presented with per rectal bleeding.

66a

CASE 66

History

A 42-year-old smoker with a family history of bowel cancer.

ANSWER 65

Observations (65a)

Single image from a double contrast barium enema examination shows abnormality of the colon that extends from the rectum to the mid transverse colon. There are features of luminal narrowing with mucosal irregularity, granularity and shallow ulceration. The disease process appears continuous along the affected segments with no further lesions seen. Normal appearances of the ileocaecal region. Normal sacroiliac joints. The appearances are in keeping with a colitis, most likely ulcerative colitis.

Diagnosis

Ulcerative colitis (UC).

Discussion

Ulcerative colitis is an idiopathic inflammatory bowel disease with involvement predominantly of the mucosa and submucosa of the large bowel. There are two peaks of presentation – 3rd–5th decades and 7th–8th decades. The most common presentation is with bloody diarrhoea and abdominal pain.

The rectum is almost always involved (96% of cases) with continuous, concentric and symmetric involvement of the colon more proximally. The terminal ileum is involved in 10–25% due to backwash ileitis. In acute inflammation there are findings of:

• Thickening of bowel wall (65b).

• Significant bowel wall thickening can lead to the classical ‘thumb-printing’ appearance.

• Widening of the presacral space. • Fine mucosal granularity. • Superficial ulceration.

• Pseudopolyps – islands of oedematous mucosa. • Collar button ulcers (65c).

Appearances in the chronic stage:

• Colon becomes rigid with luminal narrowing due to chronic inflammation, and loss of haustrations – ‘leadpipe’ colon.

• Coarse granular mucosa. • Inflammatory polyps. • Backwash ileitis.

65c Single image from a barium enema examination

shows multiple shallow barium-filled ulcers in the left sided colon.

65b Single axial CT image shows continuous

thickening of the colonic wall involving sigmoid colon. The surrounding fat is ‘dirty’ (increased attenuation) due to inflammatory change. Appearances are of an acute active colitis though the appearances here are not specific for an underlying cause.

65b

Answer 65

Abdominal Imaging

transmural, skip lesions; preferential involvement of terminal ileum. Fistulae and deep ulcers are common features.

• UC characteristically has a continuous, concentric, symmetric involvement that extends proximally from the rectum and only occasionally involves the terminal ileum. Fistulae, fissures and deep

ulceration are not features.

• Remember that although the rectum is always involved in UC, it may appear spared if steroid enemas have been used.

• Look for intestinal complications of UC including malignancy, toxic megacolon, pneumatosis intestinalis and perforation.

• Look for extraintestinal complications of UC such as sacroiliitis.

• Look for complications of treatment, e.g. steroids causing avascular necrosis (AVN) or osteoporosis.

Further management

A combined medical/surgical approach to disease manage - ment should be taken.

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65d Abdominal radiograph with features of toxic

megacolon and perforation.

65e Pelvic radiograph shows bilateral early sclerosis

of both sacroiliac joints. The condition is complicated by:

• Perforation from toxic megacolon in 5–10% – the most common cause of death (65d).

• Colonic adenocarcinoma – this complicates up to 5% of UC patients with risk highest when there is pancolitis or onset at a young age(<15 years) and increases with chronicity of disease. The rectosigmoid is the most common location for neoplastic

transformation.

• Colonic strictures – usually a single, short, smooth stricture is found, most commonly in the

rectum/sigmoid.

In addition, as with Crohn’s disease, there are a variety of extracolonic complications which include iritis, pyoderma gangrenosum, chronic active hepatitis, sclerosing cholangitis and seronegative arthritis (Figure 65e demonstrates sacroiliitis with early sclerosis of both sacroiliac joints).

Practical tips

• Differentiation of Crohn’s from UC is often possible from the imaging findings:

• Crohn’s characteristically has multiple, eccentric,

ANSWER 66

Observations (66a)

Single image from a double contrast barium examination is shown. There are multiple submucosal lesions seen scattered throughout the colon with no regional predominance. Close inspection shows that these are due to gas-filled cysts in the bowel wall. No free intra- abdominal gas is seen to suggest perforation. No linear gas collections are seen. No portal vein gas is seen.

Diagnosis

Pneumatosis cystoides intestinalis.

Discussion

Pneumatosis cystoides intestinalis is usually a benign condition of middle aged people who tend to be asymptomatic but can present with symptoms of vague abdominal pain, diarrhoea and mucous discharge. Radiological findings are of multiple small 1–5 mm gas- filled cysts in a subserosal/submucosal distribution. They are more commonly found on the mesenteric rather than antimesenteric side of the colon. The cysts can rupture

leading to pneumoperitoneum but with no symptoms of peritonitis. This cystic pneumatosis is usually a benign, innocuous condition and is associated with chronic obstructive pulmonary disease, perhaps due to air tracking from ruptured alveoli and along the mesentery via the retroperitoneum. There is also an association with mucosal disruption elsewhere in the GI tract, e.g. peptic ulcer disease.

Practical tips

Air in the bowel wall due to infarction typically appears more linear (66b) and may be associated with portal vein gas in premorbid cases.

Further management

Pneumatosis of the colon is usually not clinically significant – the importance here is to treat the patient, not the x-ray.

Further reading

Pear BL (1998). Pneumatosis intestinalis: a review.

Radio lo gy 207: 13–19.

66b Abdominal radiograph shows linear gas

opacity within the wall of the transverse colon in a patient with ulcerative colitis.