Ex Vivo Fluorescence Confocal Microscopy in Specimens of the Liver: A Proof-of-Concept Study

Simple Summary Fluorescence confocal microscopy (FCM) is a novel micro-imaging technique providing optical sections of native tissue. The method is increasingly used for the routine diagnosis of tumors and inflammatory lesions of the skin and shows promising results for the diagnosis of other organ tumors. Very few publications exist about examinations of liver tissue thus far. In this study, we compare findings of FCM-examinations of biopsies and surgical specimens of the liver with the final diagnoses from conventional histology. Ex vivo Fluorescence Confocal Microscopy (FCM) is a technique providing high-resolution images of native tissues. The method is increasingly used in surgical settings in areas of dermatology and urology. Only a few publications exist about examinations of tumors and non-neoplastic lesions of the liver. We report on the application of FCM in biopsies, surgical specimens and autopsy material (33 patients, 39 specimens) of the liver and compare the results to conventional histology. Our preliminary examinations indicated a perfect suitability for tumor diagnosis (kappa = 1.00) and moderate/good suitability for the assessment of inflammation (kappa = 0.4-0.6) with regard to their severity and localization. Macro-vesicular steatosis was reliably detected, micro-vesicular steatosis tended to be underestimated. Cholestasis and eosinophilic granules in granulocytes were not represented in the scans. The tissue was preserved as native material and maintained its quality for downstream histological, immunohistological and molecular examinations. In summary, FCM is a material sparing method that provides rapid feedback to the clinician about the presence of tumor, the degree of inflammation and structural changes. This can lead to faster therapeutic decisions in the management of liver tumors, treatment of hepatitis or in liver transplant medicine.