ASPIRATION BIOPSY CYTOLOGY FOR BREAST CANCER WITH SPECIAL REFERENCE TO FALSE NEGATIVE CASES

Abstract

The results of aspiration biopsy cytology (ABC) for 295 women with breast cancer who visited the breast clinic of Nagano Cancer Center on an out-patient basis, during the past 7 years and 3 months, were analyzed retrospectively. The true positive rate (class V. IV) of ABC for 295 breast cancers was 86.1% (254) and the false negative rate (class II-I+insufficient materials) was 9.2% (27). The false negative rate of tumors under 2.0cm in diameter was higher than that over 2.1cm. Histologically, the false negative rate was the highest in noninvasive ductal carcinomas (30.8%), followed in invasive lobular carcinomas (21.1%) of all histological types. As to the gross appearance of cut surface of the tumors, the false negative rate of unclassified type (20.0%) was the highest, while that of infiltrated type (5.9%) was the lowest of all types. In terms of histological spreading grade of cancer-invasion, the false negative rate in g (17.9%) significantly higher than that in f (5.4%). The false negative rate gradually decreased with an advanced in cancer invasion into the vessel and lymph vessel, and the same tendency was observed in lymph node involvement. The factors caused false negative in order of frequency were noninvasive ductal carcinoma + invasive ductal carcinoma with predominant intraductal component, small size of tumor and invasive lobular carcinoma. The frequency of malignant diagnosis for invasive lobular carcinoma was higher by the feeling of needle insertion into tumorous tissues than by aspiration biopsy cytology. ABC is the useful method for the diagnosis of breast cancer, but false negative diagnosis can not be avoidable. Therefore, the disposal after diagnosis of ABC must be chosen carefully, in view of the feeling when an injection-needle is inserted into the tumor.