A rare pediatric case of portal vein aneurysm thrombosis.

Portal vein aneurysm (PVA) is rarely encountered, and published papers describing this etiology in adults and children typically include only case reports or small case series. We present a clinical case of PVA in a child associated with severe complications, including diffuse thrombosis of the portal venous system. A 10-year-old boy presented with abdominal pain and vomiting, resulting in an initial diagnosis of pancreatic head tumor based on suspicious images on abdominal grayscale ultrasound. Contrast-enhanced computed tomography confirmed a diagnosis of occlusive PVA thrombosis (36 × 37 × 95 mm). Lacking drastic symptoms, the patient was treated with conservative anticoagulant therapy. On follow-up, the thrombosis appeared to shrink gradually and disappeared at 6 months based on Doppler ultrasound imaging. The PVA was reduced in size, and hepatopetal flow was restored. Surgeons and radiologists should be aware of this rare entity to ensure that a precise diagnosis can be established and to provide suitable treatment.