  Due to its superior efficiency in utilizing annotations and addressing
gigapixel-sized images, multiple instance learning (MIL) has shown great
promise as a framework for whole slide image (WSI) classification in digital
pathology diagnosis. However, existing methods tend to focus on advanced
aggregators with different structures, often overlooking the intrinsic features
of H\&E pathological slides. To address this limitation, we introduced two
pathological priors: nuclear heterogeneity of diseased cells and spatial
correlation of pathological tiles. Leveraging the former, we proposed a data
augmentation method that utilizes stain separation during extractor training
via a contrastive learning strategy to obtain instance-level representations.
We then described the spatial relationships between the tiles using an
adjacency matrix. By integrating these two views, we designed a multi-instance
framework for analyzing H\&E-stained tissue images based on pathological
inductive bias, encompassing feature extraction, filtering, and aggregation.
Extensive experiments on the Camelyon16 breast dataset and TCGA-NSCLC Lung
dataset demonstrate that our proposed framework can effectively handle tasks
related to cancer detection and differentiation of subtypes, outperforming
state-of-the-art medical image classification methods based on MIL. The code
will be released later.
