Gallbladder Carcinoma Wall Thickening

A 62-year-old woman from the North Indian Gangetic Plain presents with 4 weeks of progressive right upper quadrant pain, anorexia, weight loss, and new-onset jaundice. She has a 20-year history of untreated cholelithiasis and porcelain gallbladder noted 3 years ago. On abdominal ultrasound, the structure marked **B** (infiltrative hypoechoic mass replacing the fundal wall) is identified with loss of the echogenic interface between the gallbladder and adjacent liver parenchyma. Which of the following best describes the primary clinical significance of this imaging finding?