P-20 Pseudoglandular pattern in hepatocellular neoplasms and its diagnostic value with cytokeratin immunostain

Differentiating between benign hepatocellular adenoma (HA) and carcinoma (HCC) is important for making clinical management decisions but can be challenging. We have reported liver tumor patients being discrepantly diagnosed as or based on different interpretations of identical histologic pattern - acinar/pseudoglandular pattern. In the study early hepatocarcinogenesis, it was proposed more than 30 years ago that such structural change classified HCC, this feature has been variably used among practicing pathologists since a diagnostic criterion HCC. conducted retrospective case series to examine outcomes tumors with component Classification HA HCC follow-up. group, presented multiple (>3) masses, underwent repeatedly biopsy, resection, ablation/embolization remaining masses showing no significant changes imaging survived 2-15 until now. identified 15 cases at least focal formation H&E examination. 7 (46.7%) had in one consulting institute. However, their long-term outcomes, HA/adenomatosis most likely diagnosis. comparison, within conventional were identified. The group range from deceased 2 months diagnosis survival up after transplant. use CK7 immunostain reticulin stain characterize areas acinar Group, often encountered adenomas fatty change. may highlight patchy CK7-positivity also apparent formation. hepatocytes forming acini/pseudoglands are invariably associated dysplastic nuclear features/small cell change, those mostly negative immuno-expression (2 contained CK7-positive area). Loss currently considered we observed minor degree loss steatotic foci parenchyma, changes. On other hand, even generally preserved framework (presumably very stage HCC), pseudoglandular evidently presence expression. This demonstrated gaining immuno-positivity HA. by itself not malignancy. When seen inevitably small CK7-positivity. Thus, direct relationship malignant transformation de novo doubtful. represent bystander reparative/regenerative like biliary metaplasia non-neoplastic damage, necessarily an step hepatocarcinogenesis.