The MR mammography of phyllodes tumors of different histological grades

Abstract

Purpose: to evaluate retrospectively the MR data of the breast phyllodes tumors and to perform comparative analysis of the MR signs and the histological grade of the phyllodes tumors.Materials and methods. The analyses enrolled 27 pathologically confirmed phyllodes tumors (mean age of patient 37.8 y.o.). Following features were evaluated: tumor shape and structure, margins, size, type of contrast enhancement, foci of high signal intensity on the T1-WI, foci of hypo- or isointense signal on the T2-WI comparing with intact breast tissue, presence of cystic inclusions and the type of their margins.Results. The study included 18 benign, 4 borderline and 5 malignant phyllodes tumors. The following features showed significant correlation with the tumor grade: irregular margins of the cystic foci (p = 0.003), foci of hypoor isointense signal on the T2-WI compared with intact breast tissue (p = 0.005). Foci of high signal intensity on the T1-WI were often revealed in the malignant (3/5) and borderline tumors (2/4), but this dependence was not significant (p = 0.021). According to pathomorphological correlation the foci of the high signal intensity on the T1-WI corresponded to hemorrhages, while cystic foci with irregular margins were revealed to be foci of necrosis. The foci of hypo- or isointense signal on the T2-WI compared with intact breast tissue corresponded to the hypercellular stroma.Conclusion. Specific features of phyllodes tumors are useful in differentiation of their histological types; furthermore the MR mammography provides accurate data for planning the point of biopsy.