Local tumor progression after radiofrequency ablation shows mostly the peripheral nodular type. The site of local tumor progression shows a higher concordance rate with insufficient ablative margin than contiguous vessel and subcapsular location.

Question: A 41-day-old baby boy was referred from a maternal child health care center to our hospital for prolonged jaundice and workup for unconjugated hyperbilirubinemia. He was a full-term baby. His antenatal history was unremarkable. Physical examination found a tinge of jaundice, but there was no abdominal tenderness, intraabdominal organomegaly, or other abnormality. Laboratory data found elevated serum levels of direct bilirubin of 64 mmol/L, total bilirubin of 114 mmol/L, alkaline phosphatase of 717 IU/L, and alkaline aminotransferase of 69 IU/L; complete blood picture and serum alpha-1-antritrypsin level were normal and hepatitis serology was negative. Ultrasound examination found an abnormal oblong echogenic lesion anterior to the right portal vein (Figure A, red arrowheads), a small gallbladder (around 0.8 cm in craniocaudal length) with irregular wall (Figure B, green arrows), and absence of a normal common bile duct. Hepatobiliary isotope scan showed absence of tracer excretion from the liver to the intestines up to 24 hours after injection of the radiopharmaceutical (Figure C). What is the diagnosis? What anatomical type of the abnormality is present? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.