Preoperative aspiration cytology of breast tumors.

During a ten-year period, 1,942 aspirations of 1,906 mammary tumors in 1,874 patients were performed before excisional biopsy or mastectomy. The cytology findings were categorized as positive (1,107 cases), suspicious (152 cases), atypical (183 cases), benign (166 cases) and unsatisfactory (298 cases). All cytologically positive cases with follow-up were confirmed histologically or by clinical observation. Follow-up showed that 96% of the cases in the suspicious category, 86% of the cases in the atypical category, 51% of the cases in the benign category and 72% of the cases in the unsatisfactory category had malignant neoplasms. Aspiration cytology diagnosed 1,031 of 1,539 primary malignant mammary neoplasms (67%) and 19 of 28 neoplasms (68%) metastatic to the breast; if unsatisfactory cases are excluded, these figures become 1,031 of 1,365 cases (75%) and 19 of 25 (76%), respectively. If those cases reported as suspicious are included with the positive cases and those reported as atypical are included with the negative cases, aspiration cytology would have a sensitivity of 84% for the presence of carcinoma, a specificity of 97% for the absence of carcinoma, a predictive value of 99% for a positive diagnosis and a predictive value of 56% for a negative diagnosis; the diagnostic efficiency would be 86%. Our findings reaffirmed that the cytologic diagnosis of mammary carcinomas is reliable but that negative or inconclusive cytologic findings should not be regarded as a definitive diagnosis if there is clinical suspicion of a malignant neoplasm.