Fig. 5

Representative 2D/3D image analysis to assess suspected perineural tumor cell infiltration. Analysis of the X-ray based data set in all 3 spatial directions revealed potential perineural infiltration by a dysplastic pancreatic duct (yellow arrow), as shown in the virtual sections within the punch biopsy (a). Manual segmentation of nerve (yellow), ductal epithelium (blue), and ductal lumen (green) was performed using virtual sections within the 3D data set (a, left figure). Red arrows in (a) indicate the displayed spatial direction of the virtual 2D tissue section. Spatial representation of the segmented structures within this punch biopsy showed how the dysplastic pancreatic duct and nerve wrapped around each other (b). Subsequent H&E staining on 2D tissue sections (c, left panel), specific immunostaining of the duct epithelium with anti CK-18 antibody (c, middle panel), and visualization of different cellular and extracellular tissue components using Movat’s pentachrome stain (c, right panel) validated the close localization of the perineurium and pancreatic duct