Cystic Fibrosis Bright Pancreas

A 9-year-old boy with cystic fibrosis (homozygous F508del, diagnosed at 4 months via newborn screening) presents for annual review. He has severe pancreatic insufficiency on pancreatic enzyme replacement therapy and fat-soluble vitamin supplementation. Recent labs show fecal elastase <15 mcg/g, low vitamin A and D levels despite supplementation, and paradoxically normal serum amylase and lipase. Abdominal ultrasound is performed for pancreatic surveillance. The structure marked **A** in the diagram shows diffusely hyperechoic bright pancreatic parenchyma with echogenicity exceeding that of the adjacent liver and comparable to renal sinus fat. Which of the following best explains the sonographic appearance of the structure marked **A**?