15 year-old female patient, previously healthy, attends to the emergency room because of mid-abdominal pain, intermittent and vague, of recent onset. No other complaints and without altereations detected in the physical examination. Ultrasonography (US) showed an abdominal mass in the head of the pancreas. A computed tomography (CT) was requested, with oral and intravenous iodinated contrast, for diagnostic investigation (Images 1 and 2).

 

Question:
Considering the reported case and changes in abdominal CT, which is the most likely diagnosis?