Background: Fine-needle aspiration (FNA) biopsy of palpable breast masses along with clinical and radiologic findings can provide rapid distinction between benign and malignant lesions. A preoperative determination of invasive or in situ carcinoma assists in the planning of definitive treatment. Previous studies have concentrated on whether cytologic features adequately distinguish invasion, but to the authors' knowledge the predictive value of clinicopathologic correlation has not been investigated. The authors attempted to determine whether a malignant cytologic diagnosis for a palpable breast mass is sufficient for its definitive surgical management as an invasive neoplasm.
Methods: The authors reviewed 351 FNAs from palpable breast lesions with a cytologic diagnosis of "adenocarcinoma." The presence of invasive disease was determined by histologic demonstration of invasive carcinoma in the corresponding surgical specimen or by identifying metastatic carcinoma in the absence of another primary source.
Results: Three hundred forty-three (97.7%) palpable tumors diagnosed as adenocarcinoma by FNA proved to be invasive adenocarcinoma. The remaining eight tumors contained high grade ductal carcinoma in situ, and two of these contained foci suggestive of microinvasion.
Conclusions: A palpable breast mass with an FNA diagnosis of adenocarcinoma usually represents invasive carcinoma. A definitive treatment plan therefore can be planned based on these clinical and FNA findings.