Eosinophilic gastroenteritis (EG) is a rare disease characterized by the infiltration of one or more layers of the digestive tract by eosinophilic leukocytes. The diagnosis is confirmed by histological examination of a characteristic biopsy, but radiological features are useful for diagnostic suspicion. We report the case of an adolescent boy with recurrent epigastric pain, nausea and vomiting, in whom sonographic features and eosinophilia of the peripheral blood suggested the diagnosis of EG. Moreover, we reviewed the radiological features of EG with particular regard to the role of sonography in the diagnosis and follow-up of EG, especially in children. We emphasize the utility of sonography in pediatric patients presenting with gastrointestinal symptoms, since it may provide useful information in a quick, inexpensive and noninvasive way. Ultrasonographic detection of features such as bowel wall thickness, ascites and peritoneal nodules may be largely suggestive of EG and may prevent other invasive exams and abdominal surgery. Ultrasonography can also be easily used in the follow-up of these patients, and may obviate the frequent and potentially dangerous exposure to radiation.

A wide variety of atypical presentations with complications affecting multiple organ systems during acute infectious mononucleosis (IM) is described in the literature, with an increase in the number of teenagers who are susceptible to a severe case of the disease. We report a case of a 14-year-old girl with severe IM and acute abdominal pain. Ultrasonographic (US) evaluation showed a marked thickening of the gallbladder wall (GBW) with enlargement of some mesenteric lymph nodes. CT scan showed multiple enlarged lung nodules of various sizes and a small pleural and pericardial effusion; a hypodense solid mass of unknown etiology was detected in the anterior mediastinum, mimicking a malignant tumor. Hematological analysis of peripheral blood smear was performed to exclude neoplastic pathology. IM was identified as the only underlying disease. The patient was carefully monitored: clinical evaluation, laboratory analysis and US examination were repeated at weekly intervals, until recovery.