PAPILLARY CARCINOMA OF THE BREAST: CYTOLOGIC/HISTOLOGIC CORRELATION AND CLINICAL IMPLICATION

Introduction Papillary carcinoma (CA) of the breast is a rare lesion, whereas papilloma accounts for approximately 10% of benign breast lesions. Distinction between low-grade papillary CA and other benign lesions can be difficult. The aim of our study was to assess the usefulness of cytological diagnosis for papillary lesions of the breast. Methods Cases were obtained from Maharaj Nakorn Chiang Mai Hospital from 2000 to 2004. All breast lesions diagnosed by biopsy as papilloma or papillary CA, intraductal (DCIS) or invasive, were identified. Those with accompanying cytology examination were used for this study. Results There were 52 breast lesions diagnosed by histology including 39 cases of papilloma, 6 DCIS papillary CA, and 7 invasive papillary CA. Twenty-nine of these cases had a preceding cytological examination. Cytology results were available for 19/39 cases diagnosed as papilloma. The cytological diagnoses included papillary lesion(8). Of the 6 cases diagnosed as DCIS papillary CA, 4 had cytology specimens diagnosed as papillary lesion(1). Of the 7 cases diagnosed as invasive papillary CA, 6 had cytology specimens diagnosed as papillary lesion(2). Overall, 11/29(38%) cases that showed some form of papillary lesion on biopsy were identified as papillary on cytology. Conclusion In our series, a definite diagnosis of malignant papillary lesions was difficult on aspiration cytology alone. However, cytology was helpful in approximately 40% of cases in identifying papillary lesions, and such cases are recommended to proceed to biopsy. Chiang