Pneumatosis cystoides intestinalis mimicking free intraabdominal air following chemotherapy for relapsed acute myeloblastic leukemia in a transplanted neutropenic child: a case report

BACKGROUND

Pneumatosis cystoides intestinalis (PI) is a rare but important condition in which widespread air sacs are found in the submucosa, and subserosa of the bowel wall. Although it has several etiologies, children receiving chemotherapy are at risk for PI. Preferred imaging tools for the diagnosis are abdominal direct radiography and computed tomography. In patients with PI, rupture of intramural air sacs is the source of benign pneumoperitoneum, causing free air without true intestinal perforation. Intestinal perforation or obstruction are indications for surgical intervention.

CASE

Here, we present a 4-year-old patient diagnosed with acute myeloblastic leukemia (AML), who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a matched sibling donor (MSD) and developed PI after HSCT. The patient was consulted to the pediatric surgery department, and her oral feeding was stopped. Broad spectrum antibiotics (teicoplanin, metronidazol and vancomycin) were initiated. Her fever increased during the 24-hour monitoring, there was no stool passage, CRP ( > 25 mg/dL, normal value < 1 mg/dL) and abdominal distension increased and there was prolonged neutropenia and radiologic investigations could not rule out intestinal perforation, so the patient underwent exploratory laparotomy. No intestinal perforation was found. There was no sign in the intestinal wall and numerous gas-filled cysts of various sizes.

CONCLUSIONS

PI is an uncommon complication, and direct radiography/computed tomography scans are very helpful in making the diagnosis in suspicious cases. PI, should be kept in mind, especially in transplanted or relapsed leukemia patients receiving intensive chemotherapy.

Prednisolone induced pneumatosis coli and pneumoperitoneum

Pneumatosis intestinalis (PI) is defined as the presence of gas within the submucosal or subserosal layer of the gastrointestinal tract. It is a radiologic sign suspicious for bowel ischemia, hence non-viable bowel must be ruled out in patients with PI. However, up to 15% of cases with PI are not associated with bowel ischemia or acute abdomen. We described an asymptomatic patient with prednisolone-induced PI and modified the Naranjo score to aid in a surgeon’s decision-making for emergency laparotomy vs non-operative management with serial assessment in patients who are immunocompromised due to long-term steroid use.

[Diagnosis of Serous Adenocarcinoma following Pneumatosis Intestinalis Development during Bevacizumab Therapy for Cancer of Unknown Primary-A Case Report]

A 75-year-old woman was treated with TC plus Bev for cancer of unknown primary. During treatment, she presented to the clinic with chief complaints of general malaise and anorexia. On presentation, abdominal distention and upper abdominal tenderness were noted, and sepsis was suspected. A thoracoabdominal CT scan revealed prominent intramural emphysema and mesenteric gas in the ascending colon. An emergency laparotomy was performed for suspected pneumatosis intestinalis non-obstructive intestinal ischemia. However, no intra-abdominal contamination or ischemic changes were observed intraoperatively. Histological examination revealed a small adenocarcinoma on the serous surface of the ascending colon, and immunochemical staining confirmed the diagnosis of serous adenocarcinoma as the patient's primary cancer. This report describes a case in which the patient achieved long-term survival after diagnosis. It also emphasizes the importance of identifying the subset of patients with cancer of unknown primary who have a good prognosis in order to provide appropriate treatment.

[A Case of Colorectal Cancer with Asymptomatic Idiopathic Pneumatosis Intestinalis during Bevacizumab Administration]

We present the case of a 75-year-old woman who received CapeOX plus Bmab therapy(capecitabine, oxaliplatin, and bevacizumab)after primary excision for an unresectable advanced sigmoid colon cancer with remote metastasis. Pneumatosis intestinalis(i.e., the presence of isolated gas in the abdominal cavity)was revealed accidentally during a periodical imaging examination in the small intestine and transverse colon, albeit no subjective symptoms were reported. Owing to the absence of definitive evidence of pneumatosis intestinalis and gastrointestinal perforation, the patient was diagnosed with idiopathic pneumatosis intestinalis. Bmab was discontinued, and CapeOX therapy alone was continued after follow-up. Approximately 4 months later, pneumatosis intestinalis had completely disappeared. Bmab is a vascular endothelial growth factor antibody with well-known side effect of gastrointestinal-perforation. However, there have been few reports on pneumatosis intestinalis; to our knowledge, there have been no reports on pneumatosis intestinalis associated with colorectal cancer in Japan. Further, the report suggests the need for appropriate and immediate management of pneumatosis intestinalis following diagnosis.

[A Case of Pneumatosis Cystoides Intestinalis Secondary to Gefitinib Therapy for Lung Adenocarcinoma]

Pneumatosis cystoides intestinalis (PCI) is a relatively rare condition, characterized by subserosal or submucosal air within the bowel wall. Herein, we report a rare case of PCI secondary to treatment with an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). A 71-year-old man, who had received gefitinib therapy for 2 years and 5 months for lung adenocarcinoma with metastases to the bones and brain, presented with abdominal pain, diarrhea, and vomiting. Computed tomography of the abdomen revealed intramural air in the small bowel, free air in the abdomen, and moderate ascites. A diagnosis of PCI was made, and the patient was managed conservatively by discontinuing gefitinib treatment, because his vital signs were stable and there was no sign of peritonitis. The patient's symptoms gradually improved, and follow-up CT after 1 week revealed that the initial findings had almost completely resolved. Clinicians should note that treatment with gefitinib might cause PCI.

[Case of portal venous gas and pneumatosis cystoides intestinalis occurring during chemotherapy for a castration-resistant prostate cancer]

Portal venous gas is a rare complication. We present a case of hepatic portal venous gas (HPVG) and pneumatosis cystoides intestinalis (PCI) in a patient treated with docetaxel for prostate cancer. An 80-year-old man with castration-resistant prostate cancer received 5 cycles of docetaxel. Diarrhea and vomiting appeared on the 4th day of the 5th cycle. An abdominal computed tomography (CT) scan revealed HPVG and PCI. Since there were neither peritoneal irritation signs nor intestinal necrosis, we performed conservative management. The HPVG and PCI were no longer detected in the abdominal CT scan on the 18th day. Mucosal injury of the bowel wall by docetaxel might have caused HPVG and PCI. This case report is the first description of HPVG and PCI in a patient with castration-resistant prostate cancer in Japan.

[A case of pneumatosis cystoides intestinalis after neoadjuvant chemotherapy for esophageal cancer]

A man in his 60s was diagnosed with esophageal cancer (T3, N0, StageII) and treated with 5-fluorouracil and cisplatin as neoadjuvant chemotherapy (NAC). On day 18 of the second NAC course, the patient developed febrile neutropenia, and a computed tomography (CT) scan showed pneumatosis cystoides intestinalis (PCI) of the ascending and transverse colon, free air around the ascending colon, thickening of the gallbladder wall, pleural effusion, and ascites. Because there were no signs of peritoneal irritation and intestinal perforation was ruled out, conservative treatment was selected. Seven days after PCI was diagnosed, CT showed improvement in PCI and the free air had disappeared, and 26 days after the diagnosis, a subtotal esophagectomy was performed. Observation of the abdomen did not show a thickened wall or stenosis of the ascending or transverse colon. PCI could be treated conservatively, even with free air in the abdominal cavity, by comprehensively assessing not only the imaging but also the physical findings. We were able to perform radical resection of the esophageal cancer without excessive treatment for PCI.

[A case of pneumatosis cystoides intestinalis secondary to sunitinib treatment for renal cell carcinoma]

A 78-year-old man was diagnosed as having right renal cell carcinoma (RCC) with metastasis to the right lung. He received sunitinib and the treatment reduced the size of both RCC and lung metastasis. Then he received right radical nephrectomy. The pathological diagnosis was clear cell RCC. After the initial surgery, he was diagnosed with polymyalgia rheumatic and steroid therapy was started. During follow-up, local recurrence was discovered and sunitinib was then started at a dose of 25 mg/day. Two months after the treatment, abdominal computed tomography (CT) revealed colonic pneumatosis cystoides intestinalis. Administration of sunitinib was stopped and the patient was observed carefully without pursuing surgical intervention. A follow-up CT demonstrated resolution of the colonic pnumatosis.

Do alpha-glucosidase inhibitors have the potential to induce portal venous gas? -Two clinical case reports

We herein report two cases of portal venous gas (PVG) following alpha-glucosidase inhibitor (α-GI) therapy for diabetes mellitus. Anti-diabetic treatment with voglibose was commenced in the first case, while the second case was treated with miglitol. Both patients recovered without intensive treatment after discontinuing the α-GI therapy. α-GI medications may increase internal intestinal tract pressure by releasing carbon dioxide and hydrogen gas, potentially causing pneumatosis cystoides intestinalis (PCI) or PVG. Our experience suggests that α-GI therapy is an important potential cause of portal venous gas that can be treated conservatively.

[A case of pneumatosis cystoides intestinalis receiving chemotherapy for esophageal and tonsillar cancers]

A man in his 50, underwent chemotherapy for esophageal and tonsillar cancers. Diarrhea appeared on the 4th day and worsened daily. On the 12th day, free air was pointed out on abdominal X-ray and he consulted our department. At that time, there was no peritoneal irritation sign. Though CT showed pneumatosis and free air, there were neither perforation nor intestinal necrosis, therefore we diagnosed pneumatosis cystoides intestinalis (PCI). Conservative management was performed. He could ingest orally on the 14th day and was discharged on the 37th day. After that, chemotherapy was performed on several occasions for cancer, but there was no recurrence of PCI.

Intestinal alpha-glucosidase inhibitors: abdominal gas cysts

Detailed imaging studies of gas cysts in the intestinal mucosa (pneumatosis cystoides intestinalis) have been reported in around 20 patients taking acarbose, miglitolor voglibose, i.e. intestinal alpha-glucosidase inhibitors used as hypoglycaemic agents. Almost all the patients had nonspecific abdominal symptoms such as abdominal pain, abdominal distension, rectal bleeding or loss of appetite. They underwent multiple diagnostic tests before a role of the drug was raised. The disorders resolved completely when the drugs were withdrawn. In practice, as acarbose and miglitol have no proven impact on morbidity or mortality, and as they have multiple adverse effects, including gas cysts, they should not be used to treat diabetic patients.

Case report of pneumatosis intestinalis secondary to sunitinib treatment for refractory gastrointestinal stromal tumor

Pneumatosis intestinalis (PI) occurs when inter-luminal air enters the bowel wall of the gastrointestinal tract via a mucosal defect. The condition is caused by numerous disease states, direct trauma, and various drugs. When PI is secondary to drug therapy, discontinuation of the offending agent results in the resolution of PI. We report on the case of a 73-year-old male with a history of refractory gastrointestinal stromal tumor experiencing PI while on sunitinib treatment. PI was noted via computed tomography (CT) scans 68 days after starting sunitinib therapy and showed near complete resolution on a follow up CT performed one month after discontinuing sunitinib. Given that a CT scan performed five months prior to the initiation of sunitinib did not show PI, lack of abdominal symptoms in our patient, and resolution of PI after discontinuing sunitinib, the cause of PI in our patient was likely due to sunitinib treatment.

[A case of pneumatosis cystoides intestinalis induced by steroid pulse therapy for severe acute hepatitis B]

A 26-year-old Japanese woman was admitted to the hospital because of fever and general fatigue. A diagnosis of acute hepatitis B was given because of high levels of transaminase and positivity for HBs-Ag, HBe-Ag and HBc-IgM. On the 2nd day progression to fulminant hepatitis was suspected, and steroid pulse therapy, cyclosporin, entecavir, and interferon-β were started. Her laboratory data improved until transaminase showed an increase on 18th day, and steroid was once again administered. Abdominal CT scan and plain abdominal X-ray showed pneumatosis cystoides intestinalis (PCI) mainly along the ascending colon without any symptoms. After discontinuation of steroid therapy, abnormal gas gradually disappeared. This is a very rare case of PCI, which may have been caused by short-term steroid pulse therapy.

Pneumatosis intestinalis (PI) following severe traumatic brain injury

PRIMARY OBJECTIVE

To report a case of pneumatosis intestinalis complicated with sorbitol containing medicines.

RESEARCH DESIGN

Case report.

METHODS AND PROCEDURES

Clinical course and literature review.

EXPERIMENTAL INTERVENTIONS

Chart review.

MAIN OUTCOMES AND RESULTS

Large amount of sorbital may cause a reversible gastrointestinal complication, pneumatosis intestinalis.

CONCLUSIONS

In the assessment of enteral abnormalities, all components of medications, active and 'inactive', must be evaluated as possible aetiological factors of pneumatosis intestinalis.

Gas in portal circulation and pneumatosis cystoides intestinalis during chemotherapy for advanced rectal cancer

OBJECTIVES

Acute abdominal symptoms with CT scan evidence of intramural gas in bowel walls (pneumatosis cystoides intestinalis, PCI) and of gas in the portal venous blood (PBG) in patients undergoing chemotherapy may represent a worrisome picture, suggestive of bowel necrosis. This picture remains a major clinical clue and the reporting of new cases may help to share awareness and experience on management. We describe a patient with acute abdominal symptoms and evidence of PCI with PBG under cetuximab, oxaliplatin, tegafur-uracil and folinic acid chemotherapy for metastatic adenocarcinoma of the rectosigmoid junction.

METHODS

After admission for mucositis with diarrhea and profound dehydration, and subsequent emergency laparotomy for derotation of an intestinal volvulus, on the tenth postoperative day the patient developed fever and abdominal pain, with CT scan evidence of PCI with PBG. The exam of the abdomen did not suggest major problems requiring emergency surgery, and antibiotic treatment with close monitoring were performed, followed by rapid improvement.

RESULTS

Twelve days later, after resumption of oral diet, the patient unexpectedly suffered a spontaneous jejunal microperforation, requiring emergency laparotomy and bowel resection. Pathology showed that the perforation was within an area of ulceration involving the inner superficial layer of the bowel. Subsequently recovery was normal and at present, after 15 months, the patient is well and continuing chemotherapy.

CONCLUSIONS

This is probably the first report of PCI with PBG related to intestinal toxicity during cetuximab, oxaliplatin, tegafur-uracil and folinic acid chemotherapy in a patient with advanced rectal carcinoma, followed by delayed small bowel perforation. It provides an example of the challenges involved in the management of this type of patient.

Pneumatosis cystoides intestinalis induced by the α-glucosidase inhibitor miglitol

Pneumatosis cystoides intestinalis (PCI) is a rare condition in which pneumocysts develop in the submucosa or subserosa of the colon. We report herein a case of PCI induced by the alpha-glucosidase inhibitor (alphaGI) miglitol. There have been 9 recorded cases of PCI induced by other alphaGIs, but this is the first report of miglitol causing PCI. The PCI lesions in our case were smaller than those induced by voglibose or acarbose. The possibility of PCI should be considered in diabetic patients on alphaGI therapy who complain of gastrointestinal symptoms, and the gastrointestinal tract should be thoroughly investigated in these patients.

Pneumatosis intestinalis and portal venous gas without bowel ischemia in a patient treated with irinotecan and cisplatin

Pneumatosis intestinalis and gas within the portal venous system are findings predictive of bowel ischemia. The etiologies of these alarming radiographic signs are diverse and not all causes require emergent surgical intervention. The combination of pneumatosis intestinalis, portal venous gas, and acidosis typically portends bowel ischemia and inevitable necrosis. This case report is the first description of benign pneumatosis and portal venous gas secondary to irinotecan and cisplatin.

Pneumatosis cystoides intestinalis in relapsing polychondritis

Relapsing polychondritis (RP) is a rare systemic disease characterized by an inflammatory process involving predominantly cartilaginous structures. Pneumatosis cystoides intestinalis (PCI) in RP has not been reported previously. We report a case of PCI in RP that was successfully treated with high oxygen and antibiotics.

Pneumatosis coli induced by acarbose administration for diabetes mellitus. Case report and literature review

The authors report a case report of rare disease interesting the digestive tract and often associated to the other gastrointestinal pathologies and/or pulmonary diseases and can be also associated to not gastrointestinal conditions such as collagen-vascular disease, transplantation, AIDS, use of corticosteroid and chemotherapy; other causes can be iatrogenic such as traumatic gastrointestinal endoscopy (a mucoses biopsy, a polipectomy) or the assumption of lattulosio; in 15-20% of cases the pneumatosis cystoides intestinalis is considered primitive. In the our case the Pneumatosis coli was associated to administration of acarbose; in international literature only four papers in the English language were reported. Our patient showed a strongly aspecific symptomatology and easily attributable in first line or to the pathology of base (diabetic patient) or to the assumption of the acarbose; from about 7-8 months she showed unexplained episodes of crampy abdominal pain, diarrhea with 3-4 defecations/die with semiliquid and normochromic stools, tenesmus and a not better specified loss of weight. The diagnosis was been performed by colonoscopy and confirmed by abdominal CT scan with water enema and histologically; we have used the traditional radiology only to exclude the involvement of other gastroenteric districts. The patient was been treated with O2-therapy associated to antibiotics treatment; the suspension of the causal factor, the acarbose, has been of not secondary importance; the complete resolution of disease was obtained after 15 days of therapy.

[Chloral hydrate and diarrhea. A 76-year-old retired administration employee]

Ein 76-jähriger Patient klagte über eine seit zwei Monaten andauernde Diarrhoe mit schmerzlosem wässrigen Stuhlgang. In der Koloskopie fanden sich polypoide ödematöse Aufwerfungen und in der Abdomenleeraufnahme gasgefüllte Zysten. Die in diesem Fall diagnostizierte Pneumatosis intestinalis (PI) wurde auf die Einnahme von Chloralhydrat zurückgeführt. Das Absetzen führte zur vollständigen Rückbildung der Symptomatik und der beschriebenen pathologischen Befunde.

Pneumatosis intestinalis associated with immune-suppressive agents in a case of minimal change disease

We report treatment of a 38-year-old man with minimal change disease (MCD) who developed pneumatosis intestinalis (PI) during administration of immune-suppressive agents. His immunosuppressive medication had been tapered to 15 mg/day of prednisolone. MCD was steroid-resistant type. Abdominal examination and laboratory studies were not clinically remarkable. Radiologic findings were consistent with PI. Abnormal air accumulation was noted in the bowel, peritoneum, mediastinum and retroperitoneum. Conservative therapy with oxygen and metronidazole improved the PI symptoms. In 1993, a case of PI with nephrotic syndrome following steroid treatment was reported in Japan. However this is only the second case reported in the literature, and the first in English.

Gastrointestinal pneumatosis after docetaxel chemotherapy

Breast cancer is one of the most frequent neoplasms in women. New drugs, including taxanes, have improved survival in patients with metastatic disease. Quality of life and efficacy are important goals during treatment of these women. Herein, we report a 51 year-old woman with metastatic breast cancer who developed gastrointestinal pneumatosis (GIP) after the first cycle of treatment, which consisted of docetaxel and pamidronate. The symptoms disappeared after 7 days with supportive management, nasogastric intubation, parenteral fluids, and wide-spectrum antibiotics. Thereafter, weekly fractionated chemotherapy with an initial 50% dose reduction was administered. Because of adequate tolerance, the dose was increased by 25% after the second cycle, and full-dose docetaxel was administered after the third cycle. After 6 months of follow-up, the patient remained under treatment, with an Eastern Cooperative Oncology Group performance status of 1. Gastrointestinal pneumatosis has been reported in association with chemotherapy. In most patients, it is reported to be associated with neutropenia, which was not present in this patient.

Pneumatosis intestinalis following cytotoxic or immunosuppressive treatment

Pneumatosis intestinalis (PI) is an uncommon condition characterized by the presence of gas within the bowel wall. We describe 5 cases of PI that occurred after cytotoxic or immunosuppressive treatment for hematological disorders. All patients were neutropenic shortly before or at the time of diagnosis of PI, but did not show specific symptoms. The diagnosis was made by conventional X-ray and confirmed by abdominal computed tomography. Since there were no signs of secondary complications such as peritonitis, ischemia, or perforation, conservative treatment with broad-spectrum antibiotics and parenteral nutrition was initiated. All patients but 1 achieved complete resolution of PI after recovery from myelosuppression. Benign pneumoperitoneum due to PI should be considered in the differential diagnosis of free intra-abdominal air after chemotherapeutic or immunosuppressive therapy. It can be managed successfully by conservative treatment in the absence of secondary complications, if there is recovery of myelopoiesis.

Lactulose-induced pneumatosis intestinalis and pneumoperitoneum

A case of PI in a 57-year-old patient with colonic inertia treated with lactulose for PSE secondary to cirrhosis is described. The colonic inertia led to longer transit time. Retained lactulose and a build-up of carbon dioxide and hydrogen gas occurred in the setting of altered bacterial flora deficient in hydrogen metabolism. The increased gas pressure caused extravasation of air into the intestine, causing PI with pneumoperitoneum. They both resolved with discontinuation of lactulose.

A severe case of pneumatosis cystoides intestinalis with massive accumulation of gas outside the gastrointestinum

We report an unusually severe case of pneumatosis cystoides intestinalis in an adult female patient undergoing chemotherapy for lymphoblastic crisis in chronic myelogenous leukemia. An impressive accumulation of gas was not only detected within the intestinal wall and mesentery but also in the peritoneum, retroperitoneum, mediastinum and cervical subcutaneous tissue. The patient was almost asymptomatic and fully recovered within a few days of treatment. In addition to chemotherapy, the patient was receiving trimethoprim/sulfamethoxazole for pneumocystis carinii pneumonia and lactulose for constipation. Mucosal damage due to chemotherapy and depletion of tetrahydrofolic acid, changes in bowel flora induced by antibiotic treatment, and the intake of unabsorbable carbohydrates may be responsible for the severity of the disease.

Paralytic ileus accompanied by pneumatosis cystoides intestinalis after acarbose treatment in an elderly diabetic patient with a history of heavy intake of maltitol

An 87-year-old woman, diagnosed with diabetes mellitus at age 73, exhibited abdominal distention and appetite loss in March 1998. She had received acarbose as well as 5 mg per day of glibenclamide and had habitually used about 100 g of maltitol daily from 1997. She was diagnosed as having paralytic ileus accompanied by pneumatosis cystoides intestinalis (PCI). This condition subsided quickly with discontinuation of diet or cessation of acarbose and maltitol usage. The patient's condition appears to be attributable to increased gas levels produced by fermentation of disaccharides and maltitol. Decreased intestinal motility may be a result of pre-existing diabetic autonomic neuropathy and hypothyroidism. The patient's clinical course suggests that paralytic ileus and PCI should be listed as rare side effects of alpha-glucosidase inhibitors and that the drug should be used with great caution for those who consume non-digestive sugar substitutes.

Pneumatosis cystoides intestinalis: an unexpected finding in intestinal bleeding under therapy with phenprocoumon

Pneumatosis cystoides intestinalis is a rarely observed disorder on plain abdominal X-ray or colonoscopy examination. Although causing few complaints in adults, it can nevertheless lead to gastrointestinal bleeding. In the reported case, gastrointestinal bleeding was observed with coinciding pneumatosis and phenprocoumon therapy. After stopping anticoagulant therapy, pneumatosis vanished completely, thus suggesting that phenprocoumon is probably a further cause of the cystic disease. In the known list of drugs able to provoke pneumatosis, this case adds a new mechanism of affliction different to either immunosuppression or gas production.

Alkyl halides, super hydrogen production and the pathogenesis of pneumatosis cystoides coli

BACKGROUND AND AIMS

The colons of patients with pneumatosis cystoides coli produce excessive H2. Exposure to alkyl halides could explain this. Six consecutive patients who had pneumatosis cystoides coli while taking chloral hydrate (1-5+ g/day) are reported. Patients 2 and 3 were investigated after they had ceased chloral hydrate treatment. One produced methane, the other did not. (Pneumatosis cystoides coli patients are non-methanogenic according to the literature.) Both had overnight fasting breath H2 of less than 10 ppm. A literature review disclosed just one patient who was using chloral at the time of diagnosed pneumatosis cystoides coli, but an epidemic of the disease in workers exposed to trichloroethylene.

METHODS

(i) In vitro experiments with human faeces: chloral or closely related alkyl halides were added to anaerobic faecal cultures derived from four methane-producing and three non-methanogenic human subjects. H2 and CH4 gases were measured. (ii) In vivo animal experiment: chloral hydrate was added to drinking water of four Wistar rats, and faecal H2 compared with control rats.

RESULTS

Alkyl halides increased H2 up to 900 times in methanogenic and 10 times in non-methanogenic faecal cultures. The Ki of chloral was 0.2 mM. Methanogenesis was inhibited in concert with the increase in net H2. In the rat experiment, chloral hydrate increased H2 10 times, but did not cause pneumatosis.

CONCLUSIONS

Chloral and trichloroethylene are alkyl halides chemically similar to chloroform, a potent inhibitor of H2 consumption by methanogens and acetogens. These bacteria are the most important H2-consuming species in the colon. It is postulated that exposure to these alkyl halides increases net H2 production, which sets the scene for "counterperfusion supersaturation" and the formation of gas cysts. In recent times, very low prescribing rates for chloral have caused primary pneumatosis cystoides to become extremely rare. As with primary pneumatosis, secondary pneumatosis cystoides, which occurs if there is small bowel bacterial overgrowth distal to a proximally located gut obstruction, is predicted by counterperfusion supersaturation. "Inherent unsaturation" due to metabolism of O2 is a safety factor, which could explain why gas bubbles do not form more often in tissue with high H2 tension.

Pneumatosis cystoides intestinalis with pneumoperitoneum and pneumoretroperitoneum following chemotherapy

Pneumatosis cystoides intestinalis (PCI) is a relatively rare, mostly benign, condition. We report a case of chemotherapy-induced PCI with free retro- and intraperitoneal gas in a 17-year-old man with acute lymphoblastic leukemia. Chest radiography and upright abdominal radiography showed free intra- and retroperitoneal gas; computed tomography demonstrated subserosal gas collections. Conservative treatment with oxygen, metronidazol, and parenteral alimentation was performed, and PCI resolved within 2 weeks.

[Disseminated pneumoperitoneum during the therapy of lymphoma with methotrexate and cytosine arabinoside]

HISTORY AND CLINICAL FINDINGS

A 58-year-old man was treated for abdominal and inguinal recurrence of a centroblastic non-Hodgkin lymphoma with high doses of methotrexate and cytosine arabinoside. A chest radiogram, taken on the 18th day of chemotherapy to exclude pulmonary infiltration, revealed pneumoperitoneum. The patients's complaints were merely of abdominal fullness and persisting diarrhoea. His general state was hardly impaired, the abdomen soft on palpation with active peristalsis.

INVESTIGATIONS

There was aplastic anaemia (haemoglobin 9.9 g/dl, erythrocytes 3.4 x 10(6)/microliters, white cells 1000/microliters, platelets 20,000/microliters. Plain film of the abdomen and abdominal computed tomography confirmed pneumoperitoneum. Intraluminal air had caused wall dissection in the ascending and transverse colon (pneumatosis coli as cause of the pneumoperitoneum).

TREATMENT AND COURSE

There was complete absorption of the free abdominal air by the 29th day of chemotherapy under parenteral nutrition and metronidazole (3 x 500 mg daily).