History
29-year-old female with bilateral palpable breast masses.
Diagnosis
Phyllodes Tumor of the Breast on MRI
Description of Findings
Figure 1: Axial T2 weighted image demonstrates multiple bilateral lobulated masses with smooth margins and hyperintense fluid in slit-like spaces. (green arrow) Peritumoral hyperintensity is noted on the left (yellow arrow).
Figure 2 and Figure 3: Axial dynamic T1 weighted fat suppressed images before (Figure 2) and after (Figure 3) contrast administration show heterogeneous internal enhancement and dark internal septations (red arrows, Figure 3) with slow initial enhancement and plateau kinetics.
Figure 4: Maximum intensity projection image demonstrates the multiplicity of bilateral enhancing breast masses of varying sizes.
Discussion
Phyllodes tumors of the breast account for less than 1% of all breast tumors and typically present as large, mobile masses that can rapidly increase in size, sometimes causing stretching and ulceration of the overlying skin. Women between the ages of 40 and 50 are most commonly affected, with a higher incidence seen in Hispanics compared to other ethnic groups.
Phyllodes tumors can be classified as benign, borderline or malignant. On MRI, benign Phyllodes tumors demonstrate a lobulated shape and smooth margins, similar to fibroadenomas. However, Phyllodes tumors more commonly demonstrate slit-like cystic spaces on T2WI and non-enhancing septations compared to fibroadenomas. T2 peritumoral hyperintensity, reported as an indicator of malignancy, can also be seen with large Phyllodes tumors. MRI features suggestive of a malignant Phyllodes tumor include increased signal on T1WI (intratumoral hemorrhage), enlargement and irregularity of the cystic spaces on T2WI (necrosis) and iso- or hypointensity of tumor relative to breast tissue on T2 (secondary to stromal hypercellularity, an unfavorable histologic feature).
Both benign and malignant Phyllodes tumors have a propensity for recurrence and are treated with wide local excision. If tumor-to-breast ratio is sufficiently high, as in the case presented, mastectomy may be recommended.
References
Berg W, Birdwell R, et al. Diagnostic Imaging: Breast. Amirsys, p IV 2 96-99, 2006.
Yabuuchi H et al. Phyllodes Tumor of the Breast: Correlation between MR Findings and Histologic Grade. Radiology 2006; 241: 702-709.
Wurdinger S, Herzog AB, Fischer DR, Marx C, Raabe G, Schneider A, Kaiser WA. Differentiation of Phyllodes Tumors from Fibroadenomas on MRI. AJR 2005; 185: 1317-1321.
Bernstein L, Deapen D, Ross RK. The descriptive epidemiology of malignant cystosarcoma phylloides tumors of the breast. Cancer. 1993;71:3020–3024.
Case Contributed By
Bettina Gaycken, MD - Breast Imaging Fellow Sughra Raza, MD - Associate Director, Division of Breast Imaging and Director, Clinical Breast MRI Brigham and Women’s Hospital
