Validity of Nipple Discharge Cytology for Mass Screening of Breast Cancer

Abstract

From 1985 to 1995, an exfoliative cytologic examination of abnormal nipple discharge was carried out on 2, 505 patients at Tokyo Metropolitan Cancer Detection Center. Out of 80 histologically confirmed mammary carcinomas, 38 (47.4%) were correctly diagnosed as cancerous, 9 cases being suspicious, and 33 cases negative. The cytologic diagnosis of discharge from 167 benign cases was positive in 5 cases, suspicious in 5 and negative in 157.
During the study period, 89 cases of nonpalpable breast cancer were detected. Of these cases, 35 had nipple discharge and 25 were diagnosed as malignant by nipple discharge cytology. No abnormal findings were observed by mammography and ultrasonography in 15 of these 25 cases.
The majority of cases of nonpalpable breast cancers detected by nipple discharge cytology were at the early stage. Nine of these 25 cases were noninvasive ductal carcinoma and 11 were papillotubular carcinoma with minimal invasion. Extension of cancer cells to the fat tissue was found in only 3 cases, and all cases were negative for lymph node metastasis.
Cytologica misdiagnosis was mainly attributable to insuffient materials and low atypia of cancer cells. In order to obtain satisfactory results of cytology, improved techniques of obtaining nipple discharge smears are required, and the cytologic diagnosis of cancer must be based on a combination of cellular morphology and the architecture of cell clusters.