Background and Objectives: Breast cancer is a variable group of diseases with different genotypic and phenotypic subtypes. Identifying the breast cancer molecular subtype is important in directing the type of treatment. We aimed to evaluate the role of multiparametric MRI in prediction of molecular subtypes of breast cancer.

Materials and Methods: retrospective study included 135 female patients with pathologically proven invasive ductal carcinoma (IDC). Clinicopathological , morphological and dynamic contrast enhanced MRI (DCE-MRI) features were evaluated and correlated molecular subtypes based on Immunohistochemistry classification.

Results: Low histological grade (grade I &II) of (IDC) was the most common histological grade (61.5%). There were 110 (81.5%) masses and 25 (18.5%) non-mass lesions. Luminal A-like (Lum A-like) was the most common subtype in 57 (42.2%), then luminal B-like (Lum B-like) in 46 (34.1%), human epidermal growth factor receptor2 (HER2) positive in 14 (10.4%), and triple-negative (TN) was the least common subtype seen in 18 (13.3%) lesions. Spiculated mass margins and irregular shape were significantly associated with Luminal A-like (87.7%&80.7%) and Luminal B-like (85%&100%), respectively (P=0.002). Larger mass size, multifocality, non-mass enhancement were associated with HER2-enriched subtype (78.6% ,50% & 50%) respectively. Mass with oval shape, circumscribed margin, intra-tumoral high signal on T2WI, rim enhancement, and higher histological grade was highly associated with TN breast cancer (P<0.001).

Conclusions: Morphological features of breast cancer, intra-tumoral T2WI signal intensity, the pattern of enhancement determined by multiparametric MRI, as well as the histological grade of the tumor could be help