Three-dimensional reconstruction of semi-gross biostructures using 'macroserials'--1-mm-thick serial organ slices

A method for reconstructing a gross or semi-gross organ structure was developed in a pathological analysis of liver lobes surgically excised from patients with bile duct carcinoma, where the extent of the tumour was to be demonstrated three-dimensionally. Fixed material was serially sliced with a ham-slicer, producing flawless slices as thin as 1 mm. Prior to slicing, the material was temporarily 'embedded' in gelatine to hold it in shape throughout slicing. These slices ('macroserials') could be directly brought into macroscopic 3-D reconstruction, but in the case of bile duct carcinoma, microscopic examination of the slices was indispensable in determining the extent of carcinoma and precarcinomatous (dysplastic) changes. Slices 1 mm thick were embedded in paraffin using a special holder made of plywood plates which kept a slice in a flat, extended state through the dehydration process. This method of preparing thin slices not only allows the reconstruction of a gross organ structure with less effort than before, but also ensures a certain amount of accuracy in the reproduction of submacroscopic structures.