E. Ramsay Camp, Department of Surgical Oncology; George J. Chang, Department of Surgical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX
E. Ramsay Camp, MD
Department of Surgical Oncology
George J. Chang, MD, MS
Department of Surgical Oncology The University of Texas M.D. Anderson Cancer Center Houston, TX
ABSTRACT Introduction: Pneumatosis cystoides intestinalis (PCI) is defined as bowel wall gas that presents as submucosal or subserosal cysts. A variety of conditions and treatments can lead to this complication, including chemotherapy.
Results and discussion: The authors describe a case of PCI in a patient who had undergone systemic chemotherapy for squamous cell carcinoma of the tongue. The patient's PCI was treated successfully with bowel rest, total parenteral nutrition, and broad-spectrum antibiotics. The presentation, diagnosis, and treatment of this complication are discussed.
Conclusion: PCI is an uncommon complication of chemotherapy, but it should be considered in any cancer patient who presents with vague gastrointestinal or obstructive symptoms. Plain abdominal radiographs and computed tomography scanning are the best modalities for visualizing this condition. Conservative management is possible in clinically stable patients whose PCI does not result from an underlying life-threatening condition, such as ischemic intestinal necrosis.
Pneumatosis cystoides intestinalis (PCI) is an uncommon complication in which submucosal or subserosal gas cysts form in the bowel wall. Because PCI is associated with a variety of treatments and both benign and life-threatening conditions, its cause must be identified to ensure that the patient receives proper treatment. We report the case of a patient who developed PCI shortly after receiving chemotherapy for squamous cell carcinoma of the tongue. We also discuss the etiology, diagnosis, and treatment of PCI.
A 44-year-old man was referred to our institution after complications following treatment for bilateral neck recurrences of a T2 N0 M0 squamous cell carcinoma of the tongue. The carcinoma had been treated with partial glossectomy, postoperative radiation administered at 60 Gy to the oral cavity and level I and II lymph node basins, and concurrent chemotherapy with cisplatin and 5-fluorouracil. The cancer metastasized to the patient's neck 6 months later, and he received cisplatin, docetaxel, and erlotinib chemotherapy, followed by comprehensive bilateral lymph node dissections. Six weeks postoperatively, the patient underwent intensity-modulated external beam radiation therapy, administered at 60 to 66 Gy.
The patient presented to the emergency department after 10 days of radiation therapy and reported a 4-day history of nausea and vomiting. He had also experienced watery diarrhea and excessive flatulence the week before and was unable to tolerate any oral intake during the previous 24 hours. He noted no recent abdominal pain, fever, or other symptoms.
After presenting to the emergency department, the patient rested comfortably and he was in no apparent distress. His heart rate and blood pressure were normal. His abdomen was soft, nondistended, and nontender to palpation. He had normal white blood cell, hemoglobin, and platelet counts and no electrolyte abnormalities. An abdominal radiograph revealed PCI extending from the proximal colon to the splenic flexure and evidence of pneumoperitoneum (Figure 1). A subsequent computed tomography (CT) scan showed diffuse colonic wall thickening, PCI extending from the cecum to the splenic flexure, and associated free intra-abdominal air (Figure 2).
The patient was admitted to the hospital and treated with bowel rest, total parenteral nutrition, and broad-spectrum antibiotics. Hs condition progressively improved, and radiographs obtained on hospital day 6 showed resolution of his PCI. At that time, his diet was steadily advanced, which he tolerated well. The patient was discharged to home on hospital day 10.
PCI is a rare, benign disease that is characterized by subserosal or submucosal gas-filled cysts within the intestinal wall and may be associated with free intraabdominal air. PCI usually involves the small intestine, and colonic involvement is evident in 40% of cases.1 PCI has been associated with multiple medical disorders, including chronic obstructive pulmonary disease and ischemic bowel disease; immunosuppressive drugs; and some chemotherapeutic agents.2,3
The exact etiology of PCI is unknown, but the mechanical theory and the bacterial theory are two leading hypothesis.2 The mechanical theory suggests that PCI arises when gas is forced into the bowel wall as a result of trauma, obstruction, increased intra-luminal pressure, or increased peristalsis.2 Mucosal alterations or injuries provide pathways for gas and bacteria to enter the intestinal wall and have been implicated in PCI formation. Medical therapies such as corticosteroids or cytotoxic chemotherapy can impact the integrity of the intestinal wall; and chronic obstructive lung disease may cause alveoli rupture, facilitating dissection of gas along the great vessels to the mesentery and into the bowel serosa.
Advocates of the bacterial theory report that the cystic structures associated with PCI contain abnormally high levels of hydrogen (as high as 50%), a byproduct of certain bacteria, which supports the theory that bacteria cause PCI.4 Injecting bacteria into the intestinal wall of laboratory animals during preclinical investigations induced PCI,5 and PCI patients have been observed to have increased exhaled hydrogen levels, further supporting a bacterial etiology.
Patients with PCI are often asymptomatic but may present with obstructive symptoms or nonspecific gastrointestinal symptoms. PCI cannot be definitively diagnosed based on clinical or laboratory findings. Radiographic studies, such as plain abdominal radiographs or CT scans, can suggest the diagnosis in the appropriate clinical setting, but these modalities are not definitive, and diagnosing PCI based solely on radiographic findings is discouraged. It is critical for clinicians to consider the patient's complete clinical presentation when entertaining a diagnosis of PCI. If a patient's clinical presentation warrants endoscopy or laparoscopy, clinicians can expect to encounter intramural gas collections in the form of cystic structures when PCI is present.
Identifying and treating the underlying cause of a patient's PCI and addressing suspected contributing factors (like steroid use) may help resolve the condition. When PCI is discovered incidentally during laparotomy, the affected bowel does not require resection, but surgeons must rule out obstruction and confirm that the integrity of the bowel wall is not compromised. Once life-threatening causes of PCI have been ruled out, such as ischemic intestinal necrosis, severe infectious colitis, or acute inflammatory bowel disease, treatment is supportive: intravenous hydration, electrolyte repletion, pain management, and close observation.
In the rare instance when a clinically stable patient presents with few or no symptoms but demonstrates radiographic evidence of free intra-abdominal air and PCI, the combination of close observation and nonsurgical management constitute the most prudent course of action. Patients with PCI have been treated successfully using both hyperbaric oxygen and high-flow oxygen.6,7 The elevated oxygen partial pressure results in diffusion of the cystic gas and resolution of PCI. Patients with PCI have also been treated with administration of an elemental diet.8 An elemental diet is one that is completely absorbed before reaching the colon, which minimizes gas formation and decreases hydrogen levels. When a nonsurgical approach is used, clinicians should consider obtaining an interval follow-up radiograph to confirm that the PCI has resolved.
PCI is unlikely to recur following nonoperative management. Although serious complications are rare, intestinal obstruction, bleeding, and perforation may occur in patients with PCI, and close clinical observation is essential. Surgeons should remain alert for a failure to improve or abrupt changes in the patient's clinical presentation, including worsening abdominal pain, distension, nausea, vomiting, and fever. Any ongoing clinical problems may indicate the need for additional medical intervention.
PCI is a rare but benign condition that is characterized by the formation of subserosal or submucosal gas-filled cysts within the intestinal wall. PCI can result from conditions that are true surgical emergencies, such as ischemic intestinal necrosis, and it is imperative that clinicians identify what caused the patient's PCI. PCI can also mimic a surgical emergency due to the presence of free intra-abdominal air, which is why it is sometimes discovered incidentally during laparoscopy. PCI should be considered in the differential diagnosis of any asymptomatic patient who demonstrates signs of pneumatosis. If the patient is clinically stable, nonsurgical treatment of PCI is generally successful. In many cases, PCI resolves spontaneously after treating the patient for any contributory, underlying medical problem.
The authors have no relationship with any commercial entity that might represent a conflict of interest with the content of this article and attest that the data meet the requirements for informed consent and for the Institutional Review Boards.