Breast fine-needle aspirates with scant cellularity are clinically useful

Introduction: Fine-needle aspirates (FNAs) with scant cellularity are considered inadequate by current cytopathology standards. We hypothesized that such aspirates are clinically useful. Methods: A 10-year database of palpable breast lumps evaluated by FNA-based triple test (TT; FNA, breast imaging studies, and clinical breast examination) and triple test scores (TTSs; 3-9) was examined to identify FNAs with scant cellularity but without evidence of malignancy (negative SC-FNAs). These FNAs were correlated with the occurrence of any subsequent cancers (false-negative SC-FNAs) and with TTSs. Results: Among a total of 324 negative SC-FNAs, 9 cancers were subsequently found at sampled sites. Seven were associated with a suspicious or malignant TTS (scores of 5 or greater) and therefore still correctly diagnosed as malignant or suspicious for malignancy. The remaining two cancers were missed by both SC-FNA and TTS (false-negative rate for TTS of 0.6%); both had scores of 4 because of suspicious imaging. Conclusions: Scantly cellular but negative FNAs are useful (can avoid unnecessary invasive breast biopsy) in the evaluation of palpable breast masses, especially when interpreted in the context of the TT and TTS.