BLOG: 66-year-old female with an abnormal colonoscopy

She-Yan Wong, MD, is currently a third year fellow in the 3-year combined gastroenterology and transplant hepatology fellowship at Thomas Jefferson University. She completed her internal medicine training at Northwestern Memorial Hospital in Chicago, Ill., and medical school at Jefferson Medical College in Philadelphia, Penn.

She-Yan Wong

Case:

The patient is a 66-year-old female with history of non-alcoholic steatohepatitis cirrhosis who presents for average risk screening colonoscopy.

She is well-compensated without any overt complications of portal hypertension.

The patient denies any symptoms. This is her first colonoscopy.

Her past medical history, in addition to cirrhosis, includes diabetes mellitus, hypertension and hyperlipidemia. She denies any family history of colon cancer or polyps.

On physical exam, she is well appearing without jaundice, ascites or stigmata of liver disease.

During the colonoscopy, multiple smooth submucosal lesions were found in the sigmoid about 20 cm from the insertion site.

Question: What is your differential diagnosis? What is your next step?

A rectal endoscopic ultrasound was subsequently performed for further characterization of these submucosal lesions.

The mucosa and submucosa were normal

There was artifact consistent with air interface and there was no flow on Doppler to suggest the presence of varices. An injection needle was inserted into a lesion for aspiration. No material came out, but there was complete collapse of the lesion.

Question: What is your diagnosis?

Answer: Pneumatosis Cystoides Intestinalis

Discussion: Pneumatosis cystoides intestinalis is a rare condition that consists of gas-containing cysts in the submucosa or subserosa of the intestine. These cysts are made up of nitrogen, hydrogen and carbon dioxide. It can affect the small bowel, colon or both. Clinical presentation is variable and can range from being asymptomatic to causing abdominal pain, diarrhea, rectal bleeding or obstruction.

The etiology is unknown, but the literature reports associated factors such as colonoscopy, ileal surgery, chronic pulmonary disease, connective tissue disorders and ingestion of sorbitol or lactulose. The pathophysiology is also unclear. Theoretically, bowel gas can be pushed through a mucosal defect into the lymphatic channels and distributed through peristalsis, which may explain its association with colonoscopy and increased intraluminal pressure. Bacteria may also play a role as fermenting Clostridium and E. Coli can produce gas in the submucosa.

Diagnosis can be made by the appearance of submucosal lesions on colonoscopy that collapse when biopsied or injected. Endoscopic ultrasound can also be helpful as see in this case. Imaging with a CT scan on x-ray may be able to identify air in the bowel wall or radiolucent cysts.

There is no treatment necessary if the patient is asymptomatic. The literature suggests that humidified or hyperbaric oxygen may be a possible treatment. It works by increasing the partial pressure of oxygen in the blood, which increases pressure gradient of the gas in the cyst, resulting in the release of the gas and replacement with oxygen. Other treatments include antibiotics or surgical resection if these cysts cause obstruction.

In conclusion, pneumatosis cystoides intestinalis is an uncommon submucosal lesion that can be seen on colonoscopy. It is important to be familiar with this entity and distinguish it from colon polyps as there is a risk of perforation if polypectomy is performed.

References

Rodrigues-Pinto E, et al. Endoscopy. 2014; 46(S 01): E572-E573.

Azzaroli F, et al. World J Gastroenterol. 2011;17(44): 4932-4936.

Wu L, et al. World J Gastroenterol. 2013;19(30): 4973-4978.