A 37-year-old woman presents for evaluation of abnormal liver chemistries. She has long-standing obesity (current BMI 38) and has previously taken anorectic medications but not for the past several years. She takes no other medications and has not used parenteral drugs or had high-risk sexual exposure. On examination, her liver span is 13 cm; she has no spider angiomas or splenomegaly. Several sets of liver enzymes have shown transaminases two to three times normal. Bilirubin and alkaline phosphatase are normal. Hepatitis B surface antigen and hepatitis C antibody are normal, as are serum iron and total iron-binding capacity. Which of the following is the likely pathology on liver biopsy?