Abstract. Women that are diagnosed with breast cancer often undergo surgery to remove either the tumour and some of the surrounding tissue (lumpectomy) or the whole breast (mastectomy). After surgery, the excised tissue is sliced at the pathology department, where specimen radiographs of the slices are typically acquired. Representative parts of the tissue are then sampled for further processing, staining and examination under the microscope. The results of histopathological imaging are used for tumour characterisation. As the 3D structure of the specimen is inevitably lost during specimen handling, reconstructing a volume from individual specimen slices could facilitate the correlation of histology to radiological imaging. This work proposes a novel method for a whole specimen volume reconstruction and is validated on six mastectomy cases. We also demonstrate how these volumes can be used as a means to map multiple histology slides to a whole mastectomy image (MRI or CT).