(BQ) Part 2 book "Liver pathology" presentation of content: Liver allograft pathology, liver involvement in other systemic diseases, benign epithelial nodules and tumors, malignant epithelial tumors, vascular tumors, tumors with mesenchymal component. | Liver Allograft Pathology Donor Liver Evaluation Preservation Injury Acute Humoral Rejection Acute Cellular Rejection Chronic Rejection Graft Versus Host Disease (GVHD) De Novo Autoimmune Hepatitis Recurrent Diseases 7 Donor Liver Evaluation DEFINITION Biopsy assessment of the donor liver for features related to long-term functioning of graft and patient survival CLINICAL FEATURES ■■ For cadaver organ, frozen sections are performed when there are questionable factors for suitability of transplantation (., extended donor criteria such as donors older than 60 years, steatotic graft). ■■ Macrovesicular steatosis increases susceptibility to preservation/reperfusion injury. ■■ For living donors, evaluation is achieved in permanent sections. PATHOLOGIC FEATURES ■■ Features to evaluate: inflammation, fibrosis, necrosis; macrovesicular steatosis ■■ Macrovesicular steatosis (Figure 7-1A) greater than 30%: considered not suitable for transplant ■■ Distinction between macro- and microvesicular steatosis: fat droplets larger or smaller than the nuclear size of hepatocytes ■■ Microvesicular steatosis may be seen with warm ischemia, and does not adversely affect graft function. ■■ Necrosis greater than or equal to 10%: unacceptable ■■ Fibrosis greater than or equal to stage 2: unacceptable DIFFERENTIAL DIAGNOSIS ■■ Frozen artifact (Figures 7-1B, C, D) 86 Chapter 7: Liver Allograft Pathology A B FIGURE 7-1 FIGURE 7-1 (A) Steatosis, not cytoplasmic round vacuoles with sharp edges. (B) Permanent section of the same specimen as in C and D. No steatosis. (continued) Chapter 7: Liver Allograft Pathology 87 Donor Liver Evaluation (continued) c d FIGURE 7-1 FIGURE 7-1 (C) Donor liver with frozen artifact. (D) At higher magnification, many irregular vacuoles that can be mistaken for fat droplets. 88 Chapter 7: Liver Allograft Pathology Preservation Injury DEFINITION Donor liver abnormalities present in peri-operative period (about 2 weeks .