Keratin cyst as a diagnostic pitfall in aspiration cytology of phyllodes tumor.

ABSTRACT

BACKGROUND: Phyllodes tumor (PT) is a fibroepithelial lesion of breast known for presence of a heterogenous stroma. However occurrence of a keratin cyst within PT is a rare incidence. An inadequate sampling during fine needle aspiration (FNA) of such lesions may result in an erroneous cytological diagnosis. CASE REPORT In the present case, ultrasound guided FNA smears from the breast lump in a 31-year-old lady with a clinical suspicion of malignancy, were repeatedly interpreted as an epidermal inclusion cyst, which was ultimately reported as a borderline PT on mastectomy. CONCLUSION: The case report aims at highlighting the importance of a diligent FNA technique keeping in mind the possibility of the various uncommon lesions especially while dealing with such a heterogenous tumor as phyllodes.