Pneumatosis intestinalis in a radioactive iodine-refractory metastasic thyroid papillary carcinoma with BRAF(V600E) mutation treated with dabrafenib–trametinib: a case report

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. CASE PRESENTATION: A 59-year-old caucasian female with radioactive iodine-refractory metastatic thyroid papillary carcinoma with BRAF(V600E) 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.