Tuberous breast presents different degrees of severity and morphology, with clinical hallmarks including constricted breast base, reduced parenchymal volume, areolar herniation, and an elevated inframammary fold. A dual-plane technique is often recommended to provide both lower-pole expansion and upper-pole coverage. Despite extensive studies on glandular abnormalities, PMM alterations remain largely unexplored. In this retrospective study, participants were divided into two groups: 30 TB patients (TB group) and 30 controls (NON-TB group). Patients with Poland syndrome, chest wall deformities, prior breast surgeries, or incomplete medical records were excluded. Control participants had non-tuberous breasts and underwent breast MRI for cancer staging. MRI was selected for its ability to provide comprehensive muscle visualization without radiation exposure. The MRIs were performed with a 1.5T scanner using a standard breast protocol with a dedicated breast coil. T1-weighted fat-saturated and T2-weighted Dixon axial images were used to assess the PMM. Semi-automatic segmentation was performed using 3D-Slicer software [fig.1], extracting 46 radiomic features, including shape-based parameters such as volume, surface area, elongation, roundness, flatness, and principal axis lengths in three spatial planes (x, y, z). Statistical analyses assessed differences between the TB and NON-TB groups, with significance set at p < 0.05.