Core needle biopsy in fibroepithelial tumors: predicting factors for phyllodes tumors.

Objectives: This study aimed to evaluate the clinical and imaging predictive factors for the diagnosis of phyllodes tumors in patients with inconclusive results from core needle biopsy (fibroepithelial lesions).

Methods: We retrospectively analyzed data of patients who underwent surgical excision of breast lesions previously diagnosed as fibroepithelial lesions. Numeric variables were analyzed using the Shapiro-Wilk and t-tests, and categorical variables were analyzed using the chi-square and Fisher's exact tests. Multivariate logistic regression was performed to calculate odds ratios and detect predictive factors for the diagnosis of PT.

Results: A total of 89 biopsy samples were obtained from 77 patients, of which 43 were confirmed as fibroadenomas, 43 as phyllodes tumors, and 3 as other benign, non-fibroepithelial breast lesions. The mean tumor size was 3.61 cm (range, 0.8-10 cm) for phyllodes tumors and 2.4 cm (range, 0.8-7.9 cm) for fibroadenomas. The predictive factor for phyllodes tumor diagnosis was lesion size >3 cm (p<0.001).

Conclusion: Our data indicate that fibroepithelial lesions of the breast larger than 3 cm are more likely to be phyllodes tumors.