Evaluating Histologic Features to Distinguish Phyllodes Tumor From Cellular Fibroadenoma on Core Needle Biopsy Specimens


In the September issue of the American Journal of Clinical Pathology, Mayo Clinic's Saba Yasir, MBBS, Daniel Visscher, M.D., Sarah Jenkins, MS, and Aziza Nassar, M.D., conducted a study to evaluate histologic features that can help distinguish phyllodes tumor (PT) from cellular fibroadenoma (CFA) on core needle biopsy (CNB) specimens.


Cellular fibroepithelial lesions (CFELs) are a heterogeneous group of tumors encompassing CFA and PT. Distinction between the two can be challenging on core CNB specimens. To help identify the differences between the two, records of patients diagnosed with cellular fibroepithelial lesions (CFELs) on CNB specimens were reviewed. Histopathologic stromal features were evaluated on CNB specimens, including mitoses per 10 high-power fields (hpf), overgrowth, increased cellularity, fragmentation, adipose tissue infiltration, heterogeneity, subepithelial condensation, and nuclear pleomorphism.
According the to the results found, the presence of mitoses (three or more) and/or total histologic features of three or more on CNB specimens were the most helpful features in predicting PT on excision.