BACKGROUND: Pneumatosis intestinalis (PI) is a rare entity which refers to the presence of gas within the wall of the small bowel or colon which is a radiographic sign. The etiology and clinical presentation are variable. Patients with PI may present either with chronic mild non-specific symptoms or with acute abdominal pain with peritonitis. Some cases of intestinal pneumatosis have been reported as adverse events of new oncological treatments such as targeted therapies that are widely used in multiple tumors.
METHODS: A 59-year-old caucasian female with radioactive iodine-refractory metastatic thyroid papillary carcinoma with BRAFV600E mutation was treated with dabrafenib and trametinib as a compassionate use. After 4 months treatment, positron emission tomography-computed tomography (PET-CT) showed PI. At the time of diagnosis, the patient was asymptomatic without signs of peritonitis. The initial treatment was conservative and no specific treatment for PI was needed. Unfortunately, after dabrafenib-trametinib withdrawal, the patient developed tumor progression with significant clinical worsening.
CONCLUSIONS: This case report is, in our knowledge, the first description of PI in a patient treated with dabrafenib-trametinib. Conservative treatment is feasible if there are no abdominal symptoms.

Pneumatosis intestinalis (PI) is an uncommon medical condition in which gas pockets form in the walls of the gastrointestinal tract. The mechanism by which this occurs is poorly understood; however, it is often seen as a sign of serious bowel ischemia, which is a surgical emergency. Since the early days of solid organ transplantation, PI has been described in recipients of kidney, liver, heart, and lung transplant. Despite the dangerous connotations often associated with PI, case reports dating as far back as the 1970s show that PI can be benign in solid organ transplant recipients. This is an important observation, as operative intervention in these patients carries greater risk than surgical procedures in the general population. The higher operative risks in the transplant population are partly due to their immunosuppressed status and poor wound healing. Furthermore, no clear consensus exists on the optimal management of PI. Various treatment strategies such as bowel rest, antibiotics, and parenteral feeding have been implemented with similar levels of success. With the increasing use of solid organ transplantation, PI is being recognized with increasing frequency. In this review, we provide a summary of the incidence, presentation, diagnosis, and management of PI, particularly as it affects recipients of solid organ transplantation.

Pneumatosis intestinalis (PI) is a rare disorder characterized by the gas within the intestinal mucosa. This is the first report methotrexate (MTX) induced PI under hemodialysis (HD) patient. A 46-year-old man suffered rheumatoid arthritis and underwent HD at local HD center. After the initial induction of MTX, the patient showed epigastralgia and diarrhea. He was referred to our hospital and abdominal computed tomography showed significant large intestinal edema and free intraperitoneal air consistent with PI. Physicians should aware that MTX is contraindication drug for chronic kidney disease and high-flux HD may decrease MTX toxicity and oxidative stress, improving PI.

An 86-year-old man with extensive past medical history was referred to Emergency Department for evaluation of dehydration, hyperkalemia and worsening of mental status. In physical examination, abdomen was distended and tender with no bowel sounds. Abdominal computed tomographic imaging revealed pneumatosis intestinalis (PI) and hepatic portal venous gas (HPVG) in presence of severe atherosclerotic calcification of abdominal aorta.