The Great Gut Mimicker: A case report of MIS-C and appendicitis clinical presentation overlap in a teenage patient.

Background: Abdominal pain and other gastrointestinal symptoms are common presenting features of multisystem inflammatory syndrome in children (MIS-C) and can overlap with infectious or inflammatory abdominal conditions, making accurate diagnosis challenging.

Case Presentation: We describe the case of a 16-year-old female who presented with clinical symptoms suggestive of appendicitis and an abdominal computed tomography (CT) that revealed features concerning for appendicitis. After laparoscopic appendectomy, histopathology of the appendix demonstrated only mild serosal inflammation and was not consistent with acute appendicitis.

Congenital right internal mammary artery to portal vein arteriovenous malformation.

Neonatal cases of systemic artery to portal venous system arteriovenous malformations (AVMs) can present unique challenges in terms of diagnosis, management, and treatment. Prompt identification of these AVMs is necessary for minimizing long-term sequelae and optimizing prognosis. Our report describes the diagnosis and successful endovascular coil embolization of a congenital right internal mammary artery (IMA) to portal vein AVM in a young infant initially presenting during routine fetal screening with an incidentally discovered congenital thoracic vascular abnormality.