Eosinophilic Gastroenteritis

Case: 40Y Male patient presented with abdominal pain and diarrhoea. 

Plain CT image shows thickened appearing colon (orange arrows) with surrounding fat stranding. Thickening of anterior pararenal fascia is also seen bilaterally (blue arrows). 

Contrast CT images showed edematous thickening of the terminal ileum (not shown) and large bowel upto distal descending colon. Peri-colonic inflammatory fat stranding is noted. The SMA-SMV, IMA-IMV showed normal contrast opacification. 

Contrast CT images showing mild right pleural effusion (yellow arrow) and ascites (green arrows). 

Differential Leukocyte count revealed Eosinophil count of 18% initially and rose upto 68% within 3 days. Peripheral smear showed normocytic normochromic picture with marked eosinophilia. 

Colonic biopsy showed dense chronic inflammation with predominance of eosinophils - features compatible with Eosinophilic enterocolitis.

Patient was treated with Steroids and Azathioprine, improved and was asymptomatic with normalized lab parameters in the last visit.  

Eosinophilic gastroenteritis  is a rare inflammatory disorder of the gastrointestinal tract, characterized by focal or diffuse eosinophilic infiltration of the gastrointestinal tract. Clinical features and radiological findings are non-specific, so a high index of suspicion is needed, in cases of peripheral eosinophilia (seen in >60%). This usually presents with dyspepsia and diarrhoea. It may rarely cause GOO / SBO and pancreatitis. This disease was first described by Kaijser in 1937.

Although any age group can be affected, majority of patients are in the 3rd to 5th decades, with a slight male preponderance. Most patients have history of seasonal allergies, asthma, food sensitivity, eczema, elevated IgE levels. 

EG is a self-limiting disorder in most cases and usually responds well to steroids. 

Three types of EG have been mentioned, 

1. Mucosal EG (most common) : presents with fecal blood loss, anemia, weight loss due to malabsorption or protein losing enteropathy.
2. Muscularis EG : presents with obstruction (GOO/SBO).
3. Subserosal EG : manifests as eosinophilic ascites. 

Definitive diagnosis of EG requires bowel biopsy correlation demonstrating the eosinophil infiltration. In cases of the subserosal EG, high eosinophil count in a sterile ascitic fluid by paracentesis can also be demonstrated. 

Major DD would be a intestinal parasites, which necessitates stool examination to look for ova and parasites. 

Hypereosinophilic syndrome (HES) is an idiopathic condition associated with marked peripheral eosinophilia (>1500/uL for >6months) and gastroenteritis. Heart, lungs, brain and kidneys are also affected in HES. 

Imaging features are non-specific, can show edematous wall thickening. Ascites and pleural effusion can be seen. Esophagus, stomach, small bowel and also colon can be affected. 

References:

• A Review of Eosinophilic Gastroenteritis.
• Radiopaedia. 

Thanks to Dr. GP. 

Radiation enteritis

Below are the CT images of a 60y female patient, post surgery, post chemo-radiotherapy for Ca Rectum 3 months before the CT. 

CT images show 'long segment, contiguous, mild circumferential wall thickening of distal and terminal ileum, measuring length of ~30cm and maximum wall thickness of ~6mm. No peri-enteric fat stranding or lymph node enlargement seen'.  There were no sinuses or fistulae or any features of bowel stricture or obstruction.  

The blue arrows point to the thickened ileal loops. 

Radiation induced enteritis, especially of the small bowel is less often seen even though small bowel is very radiosensitive, because of its relatively increased mobility. Among small bowel the terminal ileum is the most sensitive, as it is more or less fixed. Fixation due to adhesions from a previous surgery or previous inflammation (including PID) can increase the risk of radiation induced bowel damage. Thin habitus, diabetes and hypertension can also influence the post radiation injury. 

Radiation doses >50Gy administered over 6 weeks can produce radiation induced bowel injury, which in 10% of cases might require surgical intervention. ~5-15% patients receiving >45Gy develop chronic radiation enteropathy.

The three stages of radiation enteritis are acute, subacute (2-12 months) and late phase. Acute phase is usually the mucosal inflammation, crypt abscesses, superficial ulcerations. Subacute phase, is a phase of regeneration, arteriolar sclerosis. Late phase is usually due to fibrosis. This phase can result in strictures, obstruction, fistula and sinus formation. 

👉  Point to remember : Keep in mind the differential of radiation induced bowel injury, in cases of bowel wall thickening. Especially in a post op patient, ask for history of radiotherapy. 

Ogilvie Syndrome or Acute Colonic Pseudo Obstruction

Ogilvie Syndrome

Also known as Acute Colonic Pseudo Obstruction, Ogilvie syndrome is a potentially fatal clinico-radiological conditon with features akin to large bowel obstruction without any mechanical obstruction. 

It is most commonly seen in elderly and usually unwell patients, with multiple probable or causative factors like electrolyte imbalances, diabetes mellitus, uremia (renal failure), recent surgery, medications (eg: Opioids) etc. Pathological analysis of resected specimens showed reduced intramural ganglion cells in most cases.

Even though there is no mechanical obstruction  this condition can lead to bowel gangrene and subsequent peritonitis, increasing the mortality risk. Therefore early identification of this entity and nasogastric suction, medical management (anticholinesterases), decompression by rectal tube, colonoscopic exsufflation is needed. Sometimes cecostomy under fluroscopic guidance and rarely cecectomy might be required.

Patients usually present with abdominal pain and distension with preserved bowel sounds on auscultation.

A plain abdominal radiograph usually shows dilated colonic loops (presence of haustra), more often the right colon and transverse colon, with relative lack of air fluid levels (which are more commonly seen with SBO). Rectal gas is usually seen in radiographs, indicating lack of mechanical obstruction.

CT is performed to rule out mechanical obstruction and to assess in detail the location, cause, length of obstruction, presence of vascular compromise, bowel wall thickening if any.

Ogilvie syndrome is characterized by dilated colonic loops, without any significant transition points in CT. An intermediate or gradual transition point may be seen close to the splenic flexure region. Bowel walls are not thickened. Small bowel loops are usually collapsed or non-dilated (In contrast adynamic ileus usually has dilated small bowel loops).

If the caecal diameter is <9cm, medical / conservative management  with anticholinesterases like neostigmine, nasogastric aspiration, rectal tube may suffice to relive the condition. CT enema can sometimes be therapeutic.

Caecal perforation risk is more with diameters >9cm, where a decompressive caecostomy may be required to prevent formation of gangrene and eventual perforation peritonitis.

Acute and chronic forms are recognized, with acute form being transient and associated with acute severe illness. Acute forms respond to neostigmine. Chronic forms rarely perforate, but are usually refractory, sometimes requiring subtotal colectomy for relief.

Differential considerations include Adynamic Ileus, Mechanical obstruction, pseudomembranous colitis, toxic megacolon, ischemic colitis and caecal / sigmoid volvulus.


Below is a case of Ogilvie syndrome in a 78yr old male with multiple co-morbidities and electrolyte imbalances, presenting with abdominal distension.

Here a gradual 'transition' point was seen in the proximal sigmoid colon.

The maximal caecal dimension in this case was 8.0cm (not shown).

 

The small bowel loops are seen collapsed. However in some cases of Ogilvie syndrome, due to incompetence of ileo-caecal valve, the distension can extend into the small bowel loops also.

What's your diagnosis? : Case 4 [June 25th, 2017]

25y female, feeling of mass in abdomen.

Post your answers as comment. Case answer and discussion will be posted in few days.

Click here for the ANSWER.

Neuroblastoma vs Wilm's Tumor

NB Vs Wilm's Tumor


"Calcification, suprarenal location with a displaced but normal ipsilateral kidney, vessel encasement, retrocrural adenopathy, and extension across the midline are features that allow a confident diagnosis of neuroblastoma. Paraspinal tumor may invade the spinal canal via extension through adjacent neural foramina is s/o NB."