Whole‐specimen histopathology: a method to produce whole‐mount breast serial sections for 3‐D digital histopathology imaging

Abstract

To develop a method for preparing diagnostic-quality, whole-mount serial sections of breast specimens while preserving 3-D conformation. This required supporting the fresh specimen prior to breadloafing and refining the conventional tissue processing method. The overall goal is to use digital images of whole-specimen histopathology to improve the estimation of extent of disease. To maintain a 3-D conformation, the specimen is suspended in 3.5% agar at 55 degrees C. The block is sliced at 5-mm intervals. Sectioning is performed after extended fixation in 4% formaldehyde from paraformaldehyde in 0.1 m Millonig's buffer, followed by paraffin processing using a non-routine schedule and extended paraffin infiltration. Whole-mount serial breast sections are produced with features of equal or superior quality to that which can be achieved using conventional methods. The method is compatible with some immunohistochemical stains but requires further optimization for others. The technique is currently suitable for research applications. With the reduction in processing time achievable with microwave-assisted processing, there is the potential for its use as a routine clinical method. This tool may improve the accuracy of margin estimates and identification of multifocality in breast cancer; further evaluation is necessary.