Gastric emphysema and pneumatosis intestinalis in two common marmosets with duodenal dilation syndrome.

BACKGROUND: Common marmosets (Callithrix jacchus) are widely used as primate experimental models in biomedical research. Duodenal dilation with chronic vomiting in captive common marmosets is a recently described life-threatening syndrome that is problematic for health control. However, the pathogenesis and cause of death are not fully understood. CASE PRESENTATION: We report two novel necropsy cases in which captive common marmosets were histopathologically diagnosed with gastric emphysema (GE) and pneumatosis intestinalis (PI). Marmoset duodenal dilation syndrome was confirmed in each case by clinical observation of chronic vomiting and by gross necropsy findings showing a dilated, gas-filled and fluid-filled descending duodenum that adhered to the ascending colon. A diagnosis of GE and PI was made on the basis of the bubble-like morphology of the gastric and intestinal mucosa, with histological examination revealing numerous vacuoles diffused throughout the lamina propria mucosae and submucosa. Immunostaining for prospero homeobox 1 and CD31 distinguished gas cysts from blood and lymph vessels. The presence of hepatic portal venous gas in case 1 and possible secondary bacteremia-related septic shock in case 2 were suggested to be acute life-threatening abdominal processes resulting from gastric emphysema and pneumatosis intestinalis. CONCLUSIONS: In both cases, the gross and histopathological findings of gas cysts in the GI tract walls matched the features of human GE and PI. These findings contribute to clarifying the cause of death in captive marmosets that have died of gastrointestinal diseases.

Point-of-care ultrasound evaluation of suspected necrotizing enterocolitis in the ED.

Necrotizing enterocolitis (NEC) is a rare but life-threatening diagnosis in infants presenting with bilious emesis, abdominal distension, or bloody stools. Ultrasonography has been advocated as an alternative initial imaging modality to abdominal radiography, and may be superior in the evaluation of NEC. We describe the use of point-of-care ultrasound (PoCUS) in the evaluation of suspected NEC in the emergency department (ED) when the ability to obtain immediate abdominal x-ray (AXR) was delayed due to pandemic conditions. A pre-term infant with history of bowel resection presented with non-bilious emesis, bloody stools, and slight abdominal distension. Evaluation with PoCUS identified pneumatosis intestinalis and pneumoperitoneum, which were confirmed on subsequent AXR. Pneumatosis intestinalis in a neonate is highly suggestive of NEC, but seen by itself, can be associated with milk protein allergy and Food Protein Induced Enterocolitis syndrome (FPIES). Pneumoperitoneum is considered an indication for operative intervention for NEC. The infant was re-admitted to the NICU for suspected NEC. NEC is a rare, but potentially surgical diagnosis in infants as can be FPIES, but not milk protein allergy. NEC can be identifiable using PoCUS to search for a constellation of findings that include pneumatosis intestinalis, pneumoperitoneum, free peritoneal fluid, and portal venous gas. These findings have been previously described in the PoCUS literature for other diseases, but not for a case of suspected NEC presenting to the ED.

Low-risk pneumatosis intestinalis in the pediatric surgical population.

BACKGROUND: Pneumatosis intestinalis (PI, presence of air in bowel wall) develops in a variety of settings and due to a variety of insults which is then characterized by varying severity and clinical course. Anecdotally, many of these cases are benign with few clinical sequelae; however, we lack evidence-based guidelines to help guide management of such lower-risk cases. We aimed to describe the clinical entity of low-risk PI, characterize the population of children who develop this form of PI, determine if management approach or clinical outcomes differed depending on the managing physician's field of practice, and finally determine if a shortened course of NPO and antibiotics was safe in the population of children with low-risk PI. METHODS: We performed a retrospective review of all children over age 1 year treated at Children's Hospital Colorado (CHCO), between 2009 and 2019 with a diagnosis of PI who did not also have a diagnosis of cancer or history of bone marrow transplant (BMT). Data including demographic variables, clinical course, and outcomes were obtained from the electronic medical record. Low-risk criteria included no need for ICU admission, vasopressor use, or urgent surgical intervention. RESULTS: Ninety-one children were treated for their first episode of PI during the study period, 72 of whom met our low-risk criteria. Among the low-risk group, rates of complications including hemodynamic decompensation during treatment, PI recurrence, Clostridium difficile colitis, and death did not differ between those who received 3 days or less of antibiotics and those who received more than 3 days of antibiotics. Outcomes also did not differ between children cared for by surgeons or pediatricians. CONCLUSIONS: Here, we define low-risk PI as that which occurs in children over age 1 who do not have a prior diagnosis of cancer or prior BMT and who do not require ICU admission, vasopressor administration, or urgent surgical intervention. It is likely safe to treat these children with only 3 days of antibiotic therapy and NPO. LEVEL OF EVIDENCE: Level III.

Pneumomediastinum, pneumatosis intestinalis and pneumoperitoneum in a patient with polymyositis: case-based review.

Pneumomediastinum (PnM), pneumatosis intestinalis (PI), and pneumoperitoneum (PP) are rare complications of inflammatory myositis. We present a 59-year-old polymyositis (PM) patient who experienced all three complications simultaneously. The patient who presented with proximal muscle weakness, dysphagia, and weight loss was diagnosed with PM due to elevated muscle enzymes and consistent electromyography and muscle biopsy with inflammatory myopathy. On the 45th day of her immunosuppressive treatment, PnM, PI, and PP were detected incidentally in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan performed for severe weight loss and treatment-resistant severe disease. Since the patient had no symptoms or signs of PnM and PP, no additional intervention was applied to the current treatment, and spontaneous regression was observed in the follow-up. In addition to this case, we reviewed patients with PM who developed PBM, PP, and PI in the literature.

What is the role of neutropenia in pediatric cancer patients with pneumatosis intestinalis?

BACKGROUND: We aimed to identify prognostic indicators in pneumatosis intestinalis (PI) in a pediatric oncology population. We hypothesized that neutropenia would be an independent risk factor for adverse outcomes, including the need for abdominal operation to treat PI and for the development of recurrent PI. METHODS: We performed a retrospective review of all patients treated for PI between 2009 and 2019 with a diagnosis of cancer or history of bone marrow transplant (BMT). RESULTS: Sixty-eight children were treated for their first episode of PI; 15 (22%) were not neutropenic at presentation; eight underwent urgent abdominal operation (12%). Patients with neutropenia were more likely to receive TPN, had a longer course of NPO, and received a longer course of antibiotics. Neutropenia at presentation was associated with a decreased risk of PI recurrence (40% vs 13%, p = 0.03). Children who required an abdominal operation were more likely to require vasopressors at diagnosis (50% vs 10%, p = 0.013). CONCLUSIONS: Among pediatric cancer patients, need for vasopressors at the time of PI is a marker of severe PI, with increased likelihood of requiring operative intervention. The presence of neutropenia is associated with lower rates of PI recurrence. LEVEL OF EVIDENCE: Level III.

Pneumatosis intestinalis in the pediatric oncology population: An 11-year retrospective review at Memorial Sloan Kettering Cancer Center.

BACKGROUND: Pneumatosis intestinalis (PI) is characterized by the presence of intramural gas in the gastrointestinal (GI) tract. The overall aim of this study was to review risk factors and outcome of pediatric oncology patients at our institution who developed PI. PROCEDURE: Patients diagnosed with PI between 2007 and 2018 were identified from ICD-10 coding of radiology reports at Memorial Sloan Kettering Kids, a tertiary pediatric oncology center. Outcomes of interest were (a) resolution and time to resolution of PI, (b) surgical intervention within 2 weeks of diagnosis of PI, or (c) death secondary to PI. To capture the resolution of PI, we defined the "time to recovery (TTR)" as the time elapsed between date of PI diagnosis and the date of recovery. RESULTS: Forty-two patients were identified. Within 30 days of diagnosis of PI, three patients had surgical intervention for PI (7%) and two patients died (5%) due to non-PI causes. Median TTR of PI was 4.5 days (95% CI: 3-7 days). In univariable and multivariable analyses, only steroid use in the prior 30 days was significantly associated with a faster TTR of PI (HR = 2.27 [95% CI: 1.17-4.41], p = .02). CONCLUSIONS: This is the largest case series of patients with PI in the pediatric oncology population, which reveals significantly lower surgical and mortality rates than other published PI series. For the majority of patients, conservative medical management is indicated. A prospective study is warranted to define diagnosis and management guidelines for PI in the pediatric oncology population in a cooperative group setting.

Multicenter epidemiological survey of pneumatosis intestinalis in Japan.

BACKGROUND: Pneumatosis intestinalis (PI) is a rare condition characterized by gas collection in the intestinal wall. We aimed to determine the etiology and affected segments associated with complications, treatment, and outcome. METHODS: We conducted a multicenter epidemiological survey using a standardized data collection sheet in Japan. Complicating PI was defined as strangulation or bowel necrosis, bowel obstruction, adynamic ileus, sepsis, shock, and massive gastrointestinal bleeding requiring blood transfusion. RESULTS: We enrolled 167 patients from 48 facilities. Multivariate analysis revealed that older age (adjusted OR, 1.05 and 95% confidence intervals [CI], 1.02-1.09, P = 0.0053) and chronic kidney disease (adjusted OR, 13.19 and 95% CI 1.04-167.62, P = 0.0468) were independent predictors of the small-bowel-involved type. Complicating PI was associated with the small-bowel-involved combined type (adjusted OR, 27.02 and 95% CI 4.80-152.01, P = 0.0002), the small-bowel-only type (adjusted OR, 3.94 and 95% CI 1.02-15.27, P = 0.0472), and symptomatic PI (adjusted OR, 16.24 and 95% CI 1.82-145.24, P = 0.0126). Oxygen therapy was performed in patients with a past history of bowel obstruction (adjusted OR, 13.77 and 95% CI 1.31-144.56, P = 0.0288) and surgery was performed in patients with complicating PI (adjusted OR, 8.93 and 95% CI 1.10-72.78, P = 0.0408). Antihypertensives (adjusted OR, 12.28 and 95% CI 1.07-140.79, P = 0.0439) and complicating PI (adjusted OR, 11.77 and 95% CI 1.053-131.526; P = 0.0453) were associated with exacerbation of PI. The complicating PI was the only indicator of death (adjusted OR, 14.40 and 95% CI 1.09-189.48, P = 0.0425). DISCUSSION: Small-bowel-involved type and symptomatic PI were associated with complications which were indicators of poor prognosis.

Severe small intestinal bacterial overgrowth syndrome after jejunal feeding requiring surgical intervention: a case report and review of the literature.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) is a condition of unknown prevalence characterized by an excessive amount of bacteria in the small bowel, typically resulting in vague gastrointestinal symptoms with bloating being most commonly reported. Here we describe a severe case of SIBO leading to small bowel necrosis requiring surgical intervention. CASE PRESENTATION: A 55-year-old Hispanic female with gastric outlet obstruction secondary to a newly diagnosed gastric adenocarcinoma, receiving neoadjuvant chemotherapy, developed bloody gastrostomy output and rapidly progressing nausea and abdominal distention 3 days after jejunostomy tube placement and initiation of jejunal enteral nutrition. Imaging revealed diffuse pneumatosis and portal venous gas. Surgical exploration confirmed segmental bowel necrosis requiring resection. Histologic findings were consistent with SIBO. CONCLUSIONS: Presentation of severe SIBO in the setting of intestinal stasis secondary to gastric outlet after initiation of enteral feeds is a rare phenomenon. Early recognition and diagnosis of SIBO is critical in minimizing patient morbidity and mortality.

Prognostic factors in patients with acute mesenteric ischemia-novel tools for determining patient outcomes.

BACKGROUND: Acute mesenteric ischemia (AMI) is a devastating disease with poor prognosis. Due to the multitude of underlying factors, prediction of outcomes remains poor. We aimed to identify factors governing diagnosis and survival in AMI and develop novel prognostic tools. METHODS: This monocentric retrospective study analyzed patients with suspected AMI undergoing imaging between January 2014 and December 2019. Subgroup analyses were performed for patients with confirmed AMI undergoing surgery. Nomograms were calculated based on multivariable logistic regression models. RESULTS: Five hundred and thirty-nine patients underwent imaging for clinically suspected AMI, with 216 examinations showing radiological indication of AMI. Intestinal necrosis (IN) was confirmed in 125 undergoing surgery, 58 of which survived and 67 died (median 9 days after diagnosis, IQR 22). Increasing age, ASA score, pneumatosis intestinalis, and dilated bowel loops were significantly associated with presence of IN upon radiological suspicion. In contrast, decreased pH, elevated creatinine, radiological atherosclerosis, vascular occlusion (versus non-occlusive AMI), and colonic affection (compared to small bowel ischemia only) were associated with impaired survival in patients undergoing surgery. Based on the identified factors, we developed two nomograms to aid in prediction of IN upon radiological suspicion (C-Index = 0.726) and survival in patients undergoing surgery for IN (C-Index = 0.791). CONCLUSION: As AMI remains a condition with high mortality, we identified factors predicting occurrence of IN with suspected AMI and survival when undergoing surgery for IN. We provide two new tools, which combine these parameters and might prove helpful in treatment of patients with AMI.

Current approaches to the management of pneumatosis intestinalis: an American Pediatric Surgical Association membership survey.

PURPOSE: Pneumatosis intestinalis (PI) remains difficult to treat as it can lead to a broad range of clinical sequalae and there are little published data available to guide management. Our aim was to evaluate how pediatric surgeons currently manage children with PI, how treatment varies based on etiology, and to identify opportunities to optimize current PI management strategies. METHODS: We administered a web-based survey of practicing pediatric surgeons in the United States and Canada. The survey was distributed to all members of the American Pediatric Surgical Association. RESULTS: Of 1508 distributed surveys, 333 responses were received (22% response rate); 174 were complete and included in analysis (12% analyzed). For all scenarios, respondents recommended treatment for PI include a median 7 days of bowel rest and 7 days antibiotics. Only 41% reported their approach to PI management was optimal. Ways to optimize care include treatment based on etiology (83%), decreased number of repeat images (64%), shorter NPO course (49%), and shorter antibiotic course (47%). CONCLUSION: Pediatric surgeons manage PI similarly regardless of etiology but most report this is suboptimal. Future work is needed to prospectively evaluate management protocols that consider etiology.

Pneumatosis intestinalis in children beyond the neonatal period: is it always benign?

PURPOSE: The significance and management of pediatric pneumatosis intestinalis (PI) remains poorly defined. We sought to add clarity in children beyond the neonatal period. METHODS: Pediatric patients 3 months-18 years admitted to a quaternary children's hospital with a diagnosis of PI were included in this retrospective study. Pathologic PI was defined as irreversible, transmural intestinal ischemia. RESULTS: 167 children were identified with PI. Of these children, 155 (92.8%) had benign PI and 12 (7.2%) developed pathologic PI. The most common underlying diagnosis for pathologic PI was global developmental delay (75%), although we identified a spectrum of underlying diagnoses at risk for PI. Physical exam notable for abdominal distension (p = 0.023) or guarding (p = 0.028), and imaging with portal venous gas (p < 0.001) or bowel distension (p = 0.001) were significantly associated with pathologic PI. Only 6.6% of all children underwent an operation. For those undergoing non-surgical management of benign PI, 75% of children received antibiotics and average duration of bowel rest was 6.8 days. CONCLUSIONS: PI in children is primarily a benign phenomenon and often does not warrant surgical intervention. Bowel rest and antibiotics are therapeutic strategies frequently used in the treatment of this finding.

The effect of single ventricle congenital heart disease on recurrence risk of pneumatosis intestinalis in neonates.

PURPOSE: Congenital heart disease (CHD) is a risk factor for the development of pneumatosis intestinalis (PI). Patients with single ventricle physiology (SVP) may be at higher risk of developing PI secondary to variations in systemic blood flow which affect bowel perfusion when compared to patients with biventricular physiology (BVP). We hypothesized that patients with SVP would have increased risk of recurrent PI. METHODS: A retrospective review was done from 10/2014 through 05/2020 with patients that met the following criteria: CHD, radiographic evidence of PI, and less than 1 year of age. Groups were divided based on ventricular physiology. Primary outcome was radiographic recurrence of PI and secondary outcomes were average antibiotic duration, NPO duration, median length of stay, need for GI operation, and death from PI. RESULTS: A total of 51 patients were included, 34 with SVP and 17 with BVP. 26.47% of SVP had recurrence of PI whereas no BVP experienced a recurrence of PI. There was no significant difference in any of the secondary outcomes. CONCLUSION: Our data suggest that patients with SVP are more likely to have recurrence of radiographic PI. We may need to consider patients with SVP that get PI as their own separate group.

Pneumatosis intestinalis and porto-mesenteric venous gas: a multicenter study.

BACKGROUND: Estimating the prognosis of patients with pneumatosis intestinalis (PI) and porto-mesenteric venous gas (PMVG) can be challenging. The purpose of this study was to refine prognostication to improve decision making in daily clinical routine. METHODS: A total of 290 patients with confirmed PI were included in the final analysis. The presence of PMVG and mortality (90d follow-up) were evaluated with regard to the influence of possible risk factors. Furthermore, a linear estimation model was devised combining significant parameters to calculate accuracies for predicting death in patients undergoing surgery by means of a defined operation point (ROC-analysis). RESULTS: Overall, 90d mortality was 55.2% (160/290). In patients with PI only, mortality was 46.5% (78/168) and increased significantly to 67.2% (82/122) in combination with PMVG (median survival: PI: 58d vs. PI and PMVG: 41d; p < 0.001). In the entire patient group, 53.5% (155/290) were treated surgically with a 90d mortality of 58.8% (91/155) in this latter group, while 90d mortality was 51.1% (69/135) in patients treated conservatively. In the patients who survived > 90d treated conservatively (24.9% of the entire collective; 72/290) PMVG/PI was defined as "benign"/reversible. PMVG, COPD, sepsis and a low platelet count were found to correlate with a worse prognosis helping to identify patients who might not profit from surgery, in this context our calculation model reaches accuracies of 97% specificity, 20% sensitivity, 90% PPV and 45% NPV. CONCLUSION: Although PI is associated with high morbidity and mortality, "benign causes" are common. However, in concomitant PMVG, mortality rates increase significantly. Our mathematical model could serve as a decision support tool to identify patients who are least likely to benefit from surgery, and to potentially reduce overtreatment in this subset of patients.

Blinatumomab-related pneumatosis intestinalis in a pediatric patient with relapsed acute lymphoblastic leukemia: A case report.

INTRODUCTION: Pneumatosis intestinalis is characterized by air in the subserosal or submucosal layer of the intestine, with the severity ranging from mild and asymptomatic to symptomatic with serious conditions such as intestinal ischemia and perforation requiring surgery. Although several etiologies, including those from conventional chemotherapy agents and molecular target agents, have been suggested, blinatumomab-related pneumatosis intestinalis is quite rare. CASE REPORT: An 11-year-old girl with history of B-cell ALL presented with bone marrow relapse 3 years after completion of initial chemotherapy. Reinduction chemotherapy and blinatumomab as post-reinduction consolidation were initiated. On day 28 of blinatumomab therapy, pneumatosis intestinalis from the ascending colon to the hepatic flexure was found incidentally on abdominal computed tomography.Management and outcome: After withholding blinatumomab therapy for 1 month, pneumatosis intestinalis improved significantly without abnormal gastrointestinal symptoms. Blinatumomab was resumed and safely completed. The computed tomography performed 4 months later showed complete resolution of pneumatosis intestinalis. The patient has been in good condition for over 1 year to date. DISCUSSION: To our knowledge, this is the first case report of pneumatosis intestinalis after blinatumomab therapy in a pediatric patient with relapsed precursor B-cell acute lymphoblastic leukemia. Herein, we highlight the importance of early detection of pneumatosis intestinalis through imaging follow-up during blinatumomab therapy.

Pseudo-pneumatosis of the gastrointestinal tract: its incidence and the accuracy of a checklist supported by artificial intelligence (AI) techniques to reduce the misinterpretation of pneumatosis.

PURPOSE: To assess the incidence of erroneous diagnosis of pneumatosis (pseudo-pneumatosis) in patients who underwent an emergency abdominal CT and to verify the performance of imaging features, supported by artificial intelligence (AI) techniques, to reduce this misinterpretation. METHODS: We selected 71 radiological reports where the presence of pneumatosis was considered definitive or suspected. Surgical findings, clinical outcomes, and reevaluation of the CT scans were used to assess the correct diagnosis of pneumatosis. We identified four imaging signs from literature, to differentiate pneumatosis from pseudo-pneumatosis: gas location, dissecting gas in the bowel wall, a circumferential gas pattern, and intramural gas beyond a gas-fluid/faecal level. Two radiologists reevaluated in consensus all the CT scans, assessing the four above-mentioned variables. Variable discriminative importance was assessed using the Fisher exact test. Accurate and statistically significant variables (p-value < 0.05, accuracy > 75%) were pooled using boosted Random Forests (RFs) executed using a Leave-One-Out cross-validation (LOO cv) strategy to obtain unbiased estimates of individual variable importance by permutation analysis. After the LOO cv, the comparison of the variable importance distribution was validated by one-sided Wilcoxon test. RESULTS: Twenty-seven patients proved to have pseudo-pneumatosis (error: 38%). The most significant features to diagnose pneumatosis were presence of dissecting gas in the bowel wall (accuracy: 94%), presence of intramural gas beyond a gas-fluid/faecal level (accuracy: 86%), and a circumferential gas pattern (accuracy: 78%). CONCLUSION: The incidence of pseudo-pneumatosis can be high. The use of a checklist which includes three imaging signs can be useful to reduce this overestimation.

Idiopathic pneumatosis intestinalis secondary to lactulose use in patients with cirrhosis.

BACKGROUND AND AIM: Few case reports exist that link lactulose use with pneumatosis intestinalis in cirrhotics. This study investigates the relationship between lactulose use and idiopathic pneumatosis intestinalis in a cohort of cirrhotic patients. METHODS: This case series considers several notable cases of patients with idiopathic pneumatosis intestinalis and concurrent lactulose use. Idiopathic pneumatosis intestinalis was defined as pneumatosis intestinalis with no identifiable etiology. A cohort of 119 patients with cirrhosis and pneumatosis intestinalis were identified in a tertiary care setting, via chart review by a multidisciplinary team. Eleven of these patients were found to have idiopathic pneumatosis intestinalis. Nine of these patients were being treated with lactulose. RESULTS: Six out of 9 patients with idiopathic pneumatosis intestinalis that were being treated with lactulose saw resolution of pneumatosis intestinalis following discontinuation of treatment. CONCLUSIONS: The etiology of idiopathic pneumatosis intestinalis is likely multifactorial, but lactulose might play a preventable role in its formation.

Branch-like gas in a commercial diver's liver: a case report.

We report the case of a 42-year-old commercial diver who presented with palpitations, arthralgia, tachypnea and vomiting after three hours of repetitive dives to 25-30 meters below sea level (msw). He was diagnosed with severe decompression sickness (Type II DCS) based on his dive history, his abrupt ascent to the surface within minutes, and systemic symptoms with mild hypovolemic shock. Besides remarkable cutis marmorata on the torso, the patient was also found positive for diffuse branch-like pneumatosis in the liver, mesentery and intestines on an abdominal computed tomography (CT). His vitals were relatively stable, with a soft distended abdomen and mild tenderness over the right upper quadrant. He was treated with hyperbaric oxygen (HBO2) treatment in addition to essential crystalloid resuscitation. The abdominal pneumatosis resolved completely after two HBO2 sessions. Post-diving intra-abdominal pneumatosis is a rare complication of DCS. In our case it was difficult for dive doctors to diagnose promptly because an emergency abdominal CT was not a routine for potential DCS cases. We propose that a contrast-enhanced abdominal CT, which usually involves a intravenous injection of imaging agent, should be considered in emergency management of these patients, especially when they present with gastrointestinal symptoms.

Radiography and ultrasonography of pneumatosis intestinalis in a cat.

An adult cat was presented for acute history of vomiting and collapse. Radiographs showed the presence of air within small intestinal walls and arborizing gas patterns within the liver, compatible with pneumatosis intestinalis and presumed portal venous gas, respectively. An abdominal ultrasound the following day was suggestive of gas within the intestinal wall, however, gas within the hepatic vasculature, parenchyma, or biliary tree was not evident. Due to progressive clinical deterioration of the patient, the owners elected humane euthanasia. Necropsy revealed severe necrotizing hemorrhagic enterotyphlocolitis secondary to Clostridium difficile toxin.

Pneumatosis intestinalis induced by osimertinib in a patient with lung adenocarcinoma harbouring epidermal growth factor receptor gene mutation with simultaneously detected exon 19 deletion and T790 M point mutation: a case report.

BACKGROUND: Pneumatosis intestinalis is a rare adverse event that occurs in patients with lung cancer, especially those undergoing treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). Osimertinib is the most recently approved EGFR-TKI, and its usage is increasing in clinical practice for lung cancer patients who have mutations in the EGFR gene. CASE PRESENTATION: A 74-year-old woman with clinical stage IV (T2aN2M1b) lung adenocarcinoma was determined to have EGFR gene mutations, namely a deletion in exon 19 and a point mutation (T790 M) in exon 20. Osimertinib was started as seventh-line therapy. Follow-up computed tomography on the 97th day after osimertinib administration incidentally demonstrated intra-mural air in the transverse colon, as well as intrahepatic portal vein gas. Pneumatosis intestinalis and portal vein gas improved by fasting and temporary interruption of osimertinib. Osimertinib was then restarted and continued without recurrence of pneumatosis intestinalis. Overall, following progression-free survival of 12.2 months, with an overall duration of administration of 19.4 months (581 days), osimertinib was continued during beyond-progressive disease status, until a few days before the patient died of lung cancer. CONCLUSIONS: Pneumatosis intestinalis should be noted as an important adverse event that can occur with administration of osimertinib; thus far, such an event has never been reported. This was a valuable case in which osimertinib was successfully restarted after complete recovery from pneumatosis intestinalis, such that further extended administration of osimertinib was achieved.

Pneumatosis intestinalis and pneumoretroperitoneum post steroid use in a patient with superior mesenteric artery syndrome.

Pneumatosis intestinalis (PI) refers to the presence of gas within the wall of the small or large intestine. PI can be both asymptomatic and life-threatening. The patient was a 50-year-old man with previous cervical spine abscess and osteomyelitis post debridement 4 years ago, with a heroin abuse history. He presented with abdominal distension ongoing for 4 days and vomiting for 3 times with fluid content. Abdominal computed tomography revealed pneumatosis with pneumoretroperitoneum. A surgeon was contacted and antibiotic treatment was started. The patient was kept on nothing per os and intravenous fluid supply. A drainage tube was inserted into retroperitoneum space on the same day. Tracing back his history, our patient was discharged from the hospital recently with a diagnosis of superior mesenteric artery dyndrome (SMAS), hypersensitivity pneumonitis, and asbestosis with soft tissue pleural plaques and calcified pleural plaques. During the hospitalization period, hydrocortisone dexamethasone and methylprednisolone were prescribed for hypersensitivity pneumonitis. Steroid use and SMAS maybe the cause of PI. Finally, he was discharged 5 days later with a nasojejunal and drainage tubes and was arranged for OPD follow-up. PI can be asymptomatic or life-threatening, and patient management varies based on the clinical condition. Although in this case PI was found in the emergency department, a patient's past history of underlying disease and medication should be reviewed to find the most possible etiology.