Analysis of histological features in needle core biopsy of breast useful in preoperative distinction between fibroadenoma and phyllodes tumour.

Aims: Fine Needle Aspiration Cytology (FNAC) has been replaced by Needle core biopsy (NCB) as the pathological investigation of choice in pre-operative diagnosis of breast lesions. Despite the greater yield of material with spatial information, the distinction between fibroepithelial lesions of the breast, fibroadenoma (FA) and benign phyllodes tumour (PT), remains problematic. The aim of this study was to confirm a set of histological features which may assist in the pre-operative distinction between FA and PT on NCB and to explore novel strategies to refine the analysis of the data.

Methods: Previously defined histological criteria were applied to 112 NCBs of fibroepithelial lesions of the breast. Contingency tables for frequency analysis, logistic regression, receiver operating characteristic (ROC) and linear discriminant analysis were used.

Results: Frequency analysis identifying significant differences agreed with published data. Correct categorisation was possible in 95% of cases using logistic regression analysis (age and mitotic index) and in 94% using discriminant analysis (age, mitoses and %stroma). ROC analysis identified cut off values (between FA and PT) for age (50-55 years), %stroma (85-90) and mitoses (>or=1/2.2 mm(2)).

Conclusion: The results confirm previously published observations and provide novel putative predictive tools, to be tested prospectively.