[1595] Histopathologic Characterization of 29 Explanted Livers Containing Treated Hepatocellular Carcinoma.

Mark Wang, Sambasiva Rao, Xiaoqi Lin, Zong-Ming E Chen. Northwestern University Feinberg School of Medicine, Chicago, IL

Background: In patients with non-resectable hepatocellular carcinoma (HCC), downstaging therapy has been used as a bridge to subsequent transplant. The current available therapeutic modalities include arterial Yttrium-90 (90Y) microsphere radioembolization, chemoembolization, and radiofrequency ablation (RFA). Morphologic features of treated tumors and adjacent liver parenchyma have not been carefully compared among the different modalities.
Design: A case search from 2004-2010 for explanted livers with treated HCC was performed. 14 cases (11 male and 3 female patients, mean age 63) were found to be treated with 90Y microspheres (duration between treatment and transplant ranging from 1-18 months, mean 7 months), and 15 cases (13 male and 2 female patients, mean age 59) were identified featuring treatment with RFA, chemoembolization, or both (duration between treatment and transplant ranging from 3-6 months, mean 4 months). The histopathologic characteristics of tumor and adjacent liver parenchyma were evaluated, and the results were statistically analyzed by Fisher exact test.
Results: 8 of 14 (57%) 90Y-treated livers had residual tumor with viability ranging from 5-90%, while 6 of 15 (40%) livers treated by other modalities had residual viable tumor ranging from 5-80% (p=0.29). All (100%) 90Y-treated livers demonstrated acute lobular injury in the adjacent liver parenchyma, characterized by hepatocyte necrosis, chronic inflammation, and regenerative ductular proliferation. In contrast, only 6 (40%) of the 15 non-90Y treated livers showed such changes, which were milder by comparison. Additionally, all (100%) 90Y-treated livers demonstrated marked cytologic atypia in bile ducts surrounding treated tumor. These bile ducts often showed angulated borders, occasional cribriforming patterns, and associated marked stromal fibrosis, thereby mimicking malignancy. Such changes were only noted in one (6.7%) of the livers treated by other modalities.
Conclusions: Both 90Y microsphere radioembolization and non-90Y treatment modalities appear to induce equivalent degrees of tumor necrosis. However, acute lobular changes and marked duct epithelial atypia were more common in the 90Y-treated cases. While the clinical significance of this difference remains elusive, recognizing the unique hepatocyte and bile duct morphology is helpful in histopathologic analysis of explanted livers.
Category: Liver & Pancreas

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 260, Tuesday Morning


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