We describe an unusual case of pneumatosis cystoides intestinalis (PCI) in a patient with chronic pulmonary disease. A 79-year-old woman was hospitalized due to abdominal fullness and bowel habit change. Colonoscopy revealed numerous round cystic lesions in the sigmoid colon, which bled easily on contact. Due to persistent local peritonitis, a left hemicolectomy with primary anastomosis was performed. The patient has done well in the 12 months following surgery. (Chang Gung Med J 2003;26:144-7)

Key words:
pneumatosis cystoides intestinalis.

CASE REPORT

A 79-year-old woman was admitted due to left lower quadrant pain and abdominal fullness for 3 days. She had developed a bowel habit change with mucoid diarrhea for several months. She had previously been diagnosed as having congestive heart failure, bilateral pulmonary emphysematous lesions, and a suspicious tuberculotic lesion over the right upper lobe of the lung. On gross physical examination, she was malnourished. The abdomen was distended and tympanic to percussion. The bowel sounds were hypoactive. On palpation, no palpable mass was noted. Tenderness over the left lower abdominal quadrant was also noted. Laboratory values on admission were as follows: hemoglobin 13.7 g/dl, hematocrit 41.6%, white cell blood count (WBC) 4400/mm3, neutrophils 69.0%, monocytes 11.4%, lymphocytes 18.5%, alkaline phosphatase 30 U/L, albumin 2.7 g%, and carcinoembryogenic antigen (CEA) 2.98 ng/dl. Abdominal computed tomography showed segmental narrowing of the sigmoid colon. A lower gastrointestinal series revealed long segmental multiple radiolucent cystic filling defects in the sigmoid colon. Colonoscopic examination revealed numerous round cystic lesions in the sigmoid colon, which bled easily on contact (Fig. 1). A biopsy was not performed due to concern about the local peritonitis. Due to persistent local peritonitis and the symptom occurring off and on for several months, she did not receive high-flow oxygen inhalation therapy. An exploratory laparotomy showed multiple cystic lesions protruding into the serosal layer of the sigmoid and descending colon, with an air-tight sensation. The mesentery was not involved.
A left hemicolectomy with primary anastomosis was carried out. Pathological analysis revealed multiple cobblestone-like lesions apparently associated with gas-filled cysts distributed within the mucosa and submucosa (Fig. 2). Microscopically, the cysts were mainly distributed within the submucosa and muscularis propria and were lined by multinucleated giant cells. The overlying mucosa revealed chronic inflammatory cell infiltration in the lumina propria (Fig. 3). The postoperative course was uneventful, and there has been no recurrence during the 12-month follow-up period.

DISCUSSION

PCI is characterized by the presence of gas-filled cysts in the wall of the small bowel or colon, and the left side of the colon is usually affected. Clinical manifestations are non-specific with various presenting symptoms that include: diarrhea, mucoid discharge, rectal bleeding, and constipation. The etiology of PCI is not clear, and several theories have been proposed, among which the mechanical hypothesis may have been the most likely in our case. Increased intraluminal air pressure pushes through tears in the mucosa, and air is entrapped within the lymphatic channel and bowel wall. These events might occur during partial colonic obstruction, colonoscopic complications,(5) or with excessive colonic gas production in patients with chronic obstructive pulmonary disease who are unable to excrete gas via the lungs.
Plain abdominal films may show the "stripe sign due to overlapping of the cyst walls, producing a thin line of increased density in the middle of the empty bowel lumen.(6) Barium enema examination of the lower gastrointestinal portion of the abdomen in PCI usually reveals clusters of translucent lesions along the margin of the bowel wall or multiple, smooth, filling defects throughout the colon wall that mimic either polyps or cancer. Visualization of the gas-filled cysts on colonoscopy often confirms the diagnosis of PCI in the hands of an experienced endoscopist. The disease is benign and can be managed conservatively since some lesions disappear spontaneously within months or years. The high recurrence rate (50%-78%)(4) may be due to an underlying disease such as psychiatric disorders, chronic pulmonary diseases, colitis, or the inability to completely eradicate anaerobic bacteria within the colonic mucosa.(2) Since the mortality is very high (up to 75%)(7) once these patients develop bowel obstruction or ischemia, it is advisable to perform surgical resection of the involved segment of the bowel before such conditions develop.

REFERENCES

1. Forgacs P, Wright PH, Wyatt AP. Treatment of intestinal cysts by oxygen breathing. Lancet 1973;1:579-82.
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3. Van der Linden W, Marsell R. Pneumatosis cystoides coli associated with high H2 excretion. Treatment with an element diet. Scand J Gastroenterol. 1979;14:173-4.
4. Gagliardi G, Thompson IW, Hershman MJ, Forbes A, Hawley PR, Talbot IC. Pneumatosis coli: a proposed pathogenesis based on study of 25 cases and review of the literature. Int J Colorectal Dis. 1996;11:111-8.
5. Heer M, Altorfer J, Pirovino M, Schmid M. Pneumatosis cystoides coli: a rare complication of colonoscopy. Endoscopy 1983;15:119-20.
6. Kenney JG. Pneumatosis intestinalis. Radiology 1963;14: 70-6.
7. Knechtle SJ, Davidoff AM, Rice RP. Pneumatosis intestinalis: surgical management and clinical outcome. Ann Surg. 1990;212:160-5.

From the Department of General Surgery, Tainan General Hospital, Department of Health, the Executive Yuan, Tainan; 1Department of Colon and Rectal Surgery, 2Department of Pathology, Chang Gung Memorial Hospital, Kaohsiung.
Received: Mar. 20, 2002
Accepted: Jun. 12, 2002
Address for reprints: Dr. Hong Haw Chen, Department of Colon and Rectal Surgery, Chang Gung Memorial Hospital. 123, Ta-Pei Road, Niaosung, Kaohsiung 833, Taiwan, R.O.C.
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