Phyllodes Tumor of the Breast: A Clinicopathological Evaluation of 55 Cases

Abstract

Objective: Phyllodes tumors are biphasic tumors consisting of epithelial and stromal components that account for less than 1% of all breast tumors. According to the World Health Organization (WHO) phyllodes tumors are classified into three categories as benign, borderline and malignant. It has been reported that these tumors are usually benign and both the stromal component and the epithelial component may progress to malignancy. In this descriptive study, it was aimed to present the cases of phyllodes tumor and to evaluate the clinicopathological features of these tumors in the light of the literature.

Materials and methods: In our study, 55 cases of phyllodes tumor diagnosed between 2005-2018 in the Department of Medical Pathology were retrospectively studied. A total of 55 cases were included in the study.

Results: All cases were female with a mean age of 39.7+15.2 years. Fifty-seven tumors diagnosed in 55 cases were classed as benign in 20 cases (35.1%), borderline in 14 cases (24.6%) and malignant phyllodes tumors in 23 cases (40.3%). Ductal carcinoma in situ (solid and cribriform type) were detected in one case with malignant phyllodes tumor, whereas invasive ductal carcinoma was detected in one case. Bilateral ductal carcinoma in situ was present in the patient with invasive ductal carcinoma.

Conclusion: These tumors which rapidly grow into large masses can be clinically and pathologically confused with benign lesions, macroscopic and microscopic evaluation of concomitant in situ-invasive carcinomas should be considered. Phyllodes tumors have an important role in breast surgery and pathology.

Keywords: Fibroepithelial lesion; breast; phyllodes tumor.

Figure 1

The patient admitted to the clinic with complaints of a palpable breast mass with borderline phyllodes tumor

Figure 2

a–d. Benign phyllodes tumor mammography imaging (a). Borderline phyllodes tumor mammography imaging (b). Malign phyllodes tumor mammography imaging (c). Malign phyllodes tumor magnetic resonance imaging (d)

Figure 3

a–f. Benign Phyllodes Tumor: Typical leaf-like pattern, slight increase in cellularity of the stromal component and low ki-67 proliferative index (H&E, immunohistochemistry stain ×40) (a, b). Borderline Phyllodes Tumor: Mildly increased cellularity and high ki-67 proliferative index (H&E, immunohistochemistry stain ×40) (c, d). Malign Phyllodes Tumor: Stromal overgrowth, marked cellular atypia and brisk mitotic activity and ki-67 proliferative index (H&E, immunohistochemistry stain ×100) (e, f)