Histo-MExNet: A Unified Framework for Real-World, Cross-Magnification, and Trustworthy Breast Cancer Histopathology
Authors: Enam Ahmed Taufika, Md Ahasanul Arafatha, Abhijit Kumar Ghoshb, Md. Tanzim Rezab, Md Ashad Alamc
Organizations: European University of Bangladesh, Department of Computer Science and Engineering, Dhaka, Bangladesh · BRAC University, Department of Computer Science and Engineering, Dhaka, Bangladesh · Ochsner Center for Outcomes Research, Ochsner Research, Ochsner Clinic Foundation, New Orleans, LA, 70121, USA
Accurate and reliable histopathological image classification is essential for breast cancer diagnosis. However, many deep learning models remain sensitive to magnification variability and lack interpretability. To address these challenges, we propose Histo-MExNet, a unified framework designed for scaleinvariant and uncertainty-aware classification. The model integrates DenseNet, ConvNeXt, and EfficientNet backbones within a gated multi-expert architecture, incorporates a prototype learning module for example-driven interpretability, and applies physics-informed regularization to enforce morphology preservation and spatial coherence during feature learning. Monte Carlo Dropout is used to quantify predictive uncertainty. On the BreaKHis dataset, Histo-MExNet achieves 96.97% accuracy under multi-magnification training and demonstrates improved generalization to unseen magnification levels compared to single-expert models, while uncertainty estimation helps identify out-of-distribution samples and reduce overconfident errors, supporting a balanced combination of accuracy, robustness, and interpretability for clinical decision support.
Figures & tables
Magnification Level
Benign
Malignant
Total
40 ×
625
1370
1995
100 ×
644
1437
2081
200 ×
623
1390
2013
400 ×
588
1232
1820
Total Images
2480
5429
7909
Total Patients
24
58
82
Table 1: Summary of the BreaKHis dataset, detailing the number of benign and malignant histopathology images across four magnification levels.
Benign Tumors
Malignant Tumors
Adenosis – Non-cancerous proliferation of glandular structures within the breast lobules.
Ductal Carcinoma – Malignant tumor arising from epithelial cells of the milk ducts.
Fibroadenoma – Well-circumscribed benign mass composed of fibrous and glandular tissue.
Lobular Carcinoma – Invasive malignancy originating from the lobules, often with diffuse infiltration.
Phyllodes Tumor – Rare fibroepithelial lesion with variable behavior and potential for recurrence.
Mucinous Carcinoma – Malignancy characterized by abundant extracellular mucin production.
Tubular Adenoma – Benign tumor consisting of tightly packed tubular structures with minimal atypia.
Table 2: Overview of the benign and malignant histopathological subtypes represented in the BreaKHis dataset.
Figure 1: Representative subset of the BreaKHis dataset illustrating all eight tumor subtypes across four magnification levels ( 40× , 100× , 200× , and 400× ). Each column stands for a particular form of tumor, and each row stands for a different level of magnification. This shows how tissue morphology and cellular detail change at different scales.
Figure 2: Overview of the proposed Histo-MExNet framework.Features are extracted using DenseNet201, the most effective backbone, as part with CBAM attention. These features are mapped to a prototype-aligned space and processed by several expert classifiers. The outputs of these classifiers are adaptively fused by a gating network to produce the final prediction.
Table 3: Comparison between baseline CNN architectures evaluated under Type 1 experimental settings, where models are trained and tested on the same magnification level using a random split on each type of magnification.
Figure 3: t-SNE visualization comparing how well the baseline CNNs and the proposed model using the DenseNet201 backbone separate features at a 100× magnification.
Backbone Model
Metric
Type 1: Same-Magnification
Type 2: Cross-Magnification
40X
100X
200X
400X
40X
200X
400X
DenseNet201
Accuracy
98.25%
96.88%
92.80%
88.46%
73.08%
71.93%
51.15%
F1-Score
0.983
0.969
0.927
0.881
0.716
0.690
0.393
ConvNeXt-Tiny
Accuracy
95.74%
97.84%
92.8%
90.66%
78.25 %
73.27%
51.37%
F1-Score
0.956
0.978
0.926
0.906
0.776
0.708
0.397
EfficientNetV2-S ↓
Accuracy
95.99%
92.09%
93.55%
89.84%
67.92%
72.03%
55.22%
Table 4: Performance of the proposed Histo-MExNet framework under Same-Magnification (Type 1) and Cross-Magnification (Type 2) experimental settings.
Figure 4: Comprehensive visual analysis of predictive reliability. Row 1 (a-d): Cross-magnification generalization (trained at 100× , evaluated at 40× ) comparing uncertainty and confidence distributions. Row 2 (e-h): Multi-magnification evaluation comparing variance and predictive confidence (U vs C) correlations for models trained and evaluated on data across all magnification levels.
Backbone Model
Accuracy
W-Precision
W-Recall
W-F1 Score
DenseNet201 ⋆
96.97%
0.9703
0.9697
0.9698
ConvNeXt-Tiny
93.49%
0.9352
0.9349
0.9347
EfficientNetV2-S
93.93%
0.9395
0.9393
0.939
Table 5: Performance metrics of the proposed Histo-MExNet framework under the Type 3 experimental setup, which combines all magnification levels for training and tests on a stratified split.
Figure 5: Confusion matrix for the DenseNet201 backbone under Type 3 experimental condition, trained on mixed data from all magnifications and assessed on a stratified test split.
Histological Subtype
40X
100X
200X
400X
mean
max
mean
max
mean
max
mean
max
Benign
Adenosis
1.44
4.6
0.96
3
1.68
4
1.16
4.8
Fibroadenoma
.94
2.4
0.86
3.4
.96
2.8
2.66
5.6
Phyllodes Tumor
0.9
3
1.12
3.6
1.2
4.6
0.58
1.2
Tubular Adenoma
1.26
3.2
1.78
3.28
0.98
3.2
1.68
5.8
Table 6: Quantitative Analysis of Occlusion Sensitivity Features by Class and Magnifications
Figure 6: Occlusion sensitivity study in Ductal Carcinoma. The rows indicate magnification levels of 40× , 100× , 200× , and 400× . Columns display the input picture, occlusion sensitivity map, and overlay. The red zones emphasize the individual tissue properties that have the most influence on the model’s categorization choice, with confidence ratings for each scale.
Method
40X
100X
200X
400X
All-Mag
ES-CNN [ 50 ] ↓
83.46%
79.62%
82.13%
78.3%
79.01%
HF+DNN [ 51 ]
90.87%
89.57%
91.58%
88.67%
-
CSDCNN [ 52 ]
89.4%
90.8%
88.6%
87.6%
-
Histo-MExNet ⋆
98.25%
96.88%
92.8%
88.46%
96.97%
Table 7: Comparative analysis of classification accuracy (%) between existing state-of-the-art methods and the proposed Histo-MExNet across four individual magnifications ( 40×,100×,200×,400× ) and the combined all-magnification setting.
Variant
Accuracy (%)
W-Precision
W-Recall
W-F1
Histo-MExNet
96.97
0.9703
0.9697
0.9698
A1
93.05
0.9303
0.9305
0.9296
A2
90.49
0.9051
0.9049
0.9048
A3
91.81
0.9175
0.9181
0.9176
A4
92.62
0.9259
0.9262
0.9259
Table 8: Ablation study of Histo-MExNet evaluating the impact of key components on classification performance. The table reports Accuracy, Weighted Precision, Weighted Recall, and Weighted F1-Score for the full model and variants with specific components removed, including ensemble learning (A1), hybrid loss (A2), attention module (A3), and prototype module (A4). This analysis highlights the individual contribution of each module to the overall model effectiveness.
Department of Computer Science and Engineering, Dhaka International University, Dhaka, Bangladesh · Department of Microbiology, TMSS Medical College, Bogura, Bangladesh