Identification of key challenges in liver pathology: data from a multicenter study of extramural consults.

Extramural consultation for challenging pathology cases is an important part of patient care. The specific reasons why liver cases are submitted in consultation are poorly understood. To study patterns in extramural consultation, data were gathered from 1360 liver/GI/pancreatobiliary consults submitted to 7 academic centers. Liver cases comprised 40% of consults and are the focus of this paper. They were submitted for questions on medical (61%) and tumor pathology (39%). A preliminary diagnosis was provided by the referring pathologist in 65% of cases. The most common questions in medical liver pathology were on general classification of a hepatitic pattern of injury (37%), primary biliary cirrhosis (14%), fatty liver disease (13%), autoimmune hepatitis (12%), and etiology of cirrhosis (10%). Most tumor consults were submitted for classification (83%). The most common final tumor consultant diagnoses for benign tumors were hepatic adenoma or focal nodular hyperplasia (52%) and for malignant tumors were metastatic malignancies (47%), hepatocellular carcinoma (32%), or cholangiocarcinoma (8%). For cases submitted with a diagnosis of malignancy, the diagnosis was concordant (43% of cases), concordant but with a generic diagnosis for which a more specific diagnosis could be rendered (37%), or discordant with a major change in diagnosis from malignant to benign or change in tumor type (17%). In conclusion, analysis of consult patterns identifies challenging areas in medical and tumor liver pathology, areas that benefit from consult services and can be focused on by continuing medical educational activities.