A 36-year-old woman presents with a 6-month history of progressive generalized itching, weight loss, fatigue, and yellow sclerae. She denies use of oral contraceptives or any other medication. Physical examination reveals mild jaundice and steatorrhea. Blood studies show a high cholesterol level of 350 mg/dL, elevated serum alkaline phosphatase (240 U/L), and normal levels of AST and ALT. An intravenous cholangiogram shows no evidence of obstruction. An antimitochondrial antibody test is positive; antinuclear antibodies are not present. For the patient, a liver biopsy would most likely show which of the following pathologic findings?