Pseudoangiomatous stromal hyperplasia of the breast-cytological features of two cases and review of literature

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a lesion characterized on histology by the presence of anastomosing slit like spaces embedded in a hyalinized fibrous stroma. Till date, the cytological features of PASH have been described in only 12 cases, of which two cases were diagnosed on aspiration cytology as suspicious for carcinoma and in one case, for phyllodes tumor. We describe the FNAC findings of two of our cases of PASH. The first case was diagnosed as a phyllodes tumor and the other case as a benign proliferative breast disease, possibly a fibroadenoma. A review of the published literature on cytology of PASH shows the morphological variations that can exist in the cytology smears of this lesion. FNAC findings of PASH are non-specific, and the role of FNAC in PASH is to confirm the benign nature of the lesion, rather than provide a definitive pre-surgical diagnosis.