Pathological Analysis of 15 Cases of Phyllodes Tumors of the Breast

ABSTRACT

Retrospective clinicopathologic analysis of 15 patients with the phyllodes tumors(PT) of the breast, diagnosed at SNUH over 6 years period, was done. By light microscopy, 8 cases were diagnosed as benign, and 7 cases were diagnosed as malignant. Mean ages o the patients were 37 and 34 years in malignant and benign, respectively. Most of those cases were presented with a palpable mass of the breast. None of the patients with malignant PT had distant metastasis, Local recurrences were experienced in 3 patients among the malignant PT, and one patient among the benign PT. One of 7 malignant PT was coexisted with simultaneous ipsilateral infiltrating duct carcinoma. The clinical course was not well correlated with pathologic features. The prognostic significances of several histopathologic parameters were assessed for possible correlation with local recurrence, metastasis and death; stromal cellularity, stromal cellular atypism, mitotic activity, tumor contour, necrosis, tumor size and heterologous stromal elements. Immunohistochemistry using antibody to vimentin, proliferating cell nuclear antigen(PCNA) and epidermal growth factor receptor(EGF-R) were analysed. In the 5 cases of benign PT, the stromal cells stained diffusely positive for vimentin and 3 cases of malignant tumors show similar staining for vimentin. The percentage of PCNA-positive cells were higher in the malignant PT than in the benign ones; they were 3.5% to 60% in malignancy, while they were less than 60% in all benign PT. The results of EGF-R staining were correlated with the histologic classification; only 2 cases out of 8 benign PT show diffusely positive staining of EGF-R in the cytoplasm, but 6 cases out of 7 malignant PT show positive findings.