A 39-year-old male patient attended a general practitioner complaining of chronic dizziness, pruritus and asthenia for the past five years with cyclical waxing and waning of symptoms. He reported worsening of his condition 6 weeks before, with the development of jaundice, abdominal distension, constipation and coluria. He denied any alterations in the color of the stools. On examination, he presented with jaundice (+/4+), painful epigastric and hypocondriac palpation and a liver palpable 2.5 cm below the right costal margin. No abnormalities were found in an abdominal ultrasound performed one month before. Laboratorial data included increased alkaline phosphatase, gamma glutamyl transpeptidase (GGT) and bilirubin levels.

Question:
Based on the clinical history and images provided, which is the most likely diagnosis?