Granulomatous Mastitis: What Radiologists Should Know With Imaging Examples of Biopsy Proven Cases

A sonogram radiomics model for differentiating granulomatous lobular mastitis from invasive breast cancer: a multicenter study

PURPOSE

To construct a nomogram based on sonogram features and radiomics features to differentiate granulomatous lobular mastitis (GLM) from invasive breast cancer (IBC).

MATERIALS AND METHODS

A retrospective collection of 213 GLMs and 472 IBCs from three centers was divided into a training set, an internal validation set, and an external validation set. A radiomics model was built based on radiomics features, and the RAD score of the lesion was calculated. The sonogram radiomics model was constructed using ultrasound features and RAD scores. Finally, the diagnostic efficacy of the three sonographers with different levels of experience before and after combining the RAD score was assessed in the external validation set.

RESULTS

The RAD score, lesion diameter, orientation, echogenicity, and tubular extension showed significant differences in GLM and IBC (p < 0.05). The sonogram radiomics model based on these factors achieved optimal performance, and its area under the curve (AUC) was 0.907, 0.872, and 0.888 in the training, internal, and external validation sets, respectively. The AUCs before and after combining the RAD scores were 0.714, 0.750, and 0.830 and 0.834, 0.853, and 0.878, respectively, for sonographers with different levels of experience. The diagnostic efficacy was comparable for all sonographers when combined with the RAD score (p > 0.05).

CONCLUSION

Radiomics features effectively enhance the ability of sonographers to discriminate between GLM and IBC and reduce interobserver variation. The nomogram combining ultrasound features and radiomics features show promising diagnostic efficacy and can be used to identify GLM and IBC in a noninvasive approach.

Inflammatory diseases of the breast

Inflammatory disorders of the breast are common benign breast conditions. Lactational mastitis occurs in breastfeeding women and may be associated with breast abscess in severe cases. Non-lactational inflammatory disorders are less common and include idiopathic granulomatous mastitis, periductal mastitis, and tuberculous mastitis. While these disorders have some similarities in their presentation, each disorder requires a specific treatment regimen for resolution, and correct diagnosis is crucial for appropriate treatment. In this chapter, we will review the presentation, diagnosis, and management of each of these distinct clinical entities.