We introduce Multi-scale Adaptive Recurrent Biomedical Linear-time Encoder (MARBLE), the first purely Mamba-based multi-state multiple instance learning (MIL) framework for whole-slide image (WSI) analysis. MARBLE processes multiple magnification levels in parallel and integrates coarse-to-fine reasoning within a linear-time state-space model, efficiently capturing cross-scale dependencies with minimal parameter overhead. WSI analysis remains challenging due to gigapixel resolutions and hierarchical magnifications, while existing MIL methods typically operate at a single scale and transformer-based approaches suffer from quadratic attention costs. By coupling parallel multi-scale processing with linear-time sequence modeling, MARBLE provides a scalable and modular alternative to attention-based architectures. Experiments on five public datasets show improvements of up to 6. 9\% in AUC, 20. 3\% in accuracy, and 2. 3\% in C-index, establishing MARBLE as an efficient and generalizable framework for multi-scale WSI analysis.
Dwarampudi et al. (Mon,) studied this question.