In Search of Specimen Adequacy in Fine-Needle Aspirates of Nonpalpable Breast Lesions

Abstract

Pathology-related medical malpractice claims frequently concern fine-needle aspirations (FNAs) of breast lesions, and diagnostic errors have been attributed in part to the inadequacy of the specimens. Cytologic criteria for adequate FNA specimens, specifically in cases without malignancy, have not been clearly defined.From January 1988, to August 1995, 669 ultrasonographicguided FNAs of nonpalpable, solid breast lesions with subsequent histologic examination were performed at our institution. From these, 54 cases with cytologic diagnoses of insufficient or nonspecific benign findings were identified. All aspirates were reviewed, and the number and size of the epithelial cell groups were quantitated in each case. By using criteria for adequate aspirates of palpable breast lesions (six or more epithelial cell groups per case with a minimum of 5-10 cells per group), 23 of the 54 aspirates were deemed inadequate and 31 adequate. Eleven (48%) of the inadequate aspirates and 17 (55%) of the adequate aspirates were from histologically confirmed carcinomas (ductal carcinoma in situ, 6; invasive carcinoma, 22, of which 12 were ductal, 7, lobular, and 3, mixed ductal and lobular). For the mammographic diagnoses "probably benign," "indeterminate," and "suggestive of malignancy or malignant," the probability of malignancy in aspirates of adequate cellularity (eg, > 6 epithelial groups) was 9%, 40%, and 93%, respectively.These findings indicate that a significant proportion of breast aspirates still may yield false-negative results despite adequate to high cellularity. Although a definition of adequacy based on cellularity is useful in reducing false-negative results, cellularity alone cannot be relied on in the management of nonpalpable lesions. For mammographic findings that are indeterminate or suggestive of malignancy or malignant, nonspecific FNA findings should be followed by core or excisional biopsy to exclude carcinoma. In a recent review of pathology-related medical malpractice claims, 10% of the cases concerned diagnoses made from fine-needle aspiration (FNA) of breast lesions, and, in many cases, these diagnostic errors were the result of inadequate FNA specimens. 1Because diagnoses given based on findings from breast aspirates frequently dictate subsequent patient management, it is clear that evaluation of the adequacy of such specimens is crucial. Pathologists agree that the adequacy of breast aspirates is influenced by a variety of factors, such as clinical findings, lesion type, and specimen procurement, and, therefore, cannot be evaluated solely on the basis of cytologic findings. Nevertheless, in daily practice, cytologic parameters such as the degree of specimen cellularity traditionally have been considered when assessing the adequacy of a specimen for interpretation. Specific cytologic criteria for FNA specimen adequacy, however, have not been clearly defined and vary among different authors in the number and type of cells, the number of slides, and the number of needle passes required. Some authors requ...

Breast fine‐needle aspiration samples reported as “proliferative breast lesion”: Clinical utility of the subcategory “proliferative breast lesion with atypia”

“…17,21 By analysis of the surgical specimens, the latter appears to be the main factor in our study group. Sampling was relatively less of a problem because cytopathologists performed the majority of the breast FNAs in this study by, and immediate on site assessment for adequacy was routine.…”

“…Similar findings were reported in other studies. 21,30 It would not be practical, and usually would not be possible, to diagnose ADH on FNA considering the afore mentioned challenges in the histologic diagnosis of ADH.…”

Triple Test Approach to Inadequate Fine Needle Aspiration Biopsies of Palpable Breast Lesions

“…5,11,14,16,17 Utilizing cell count as the criterion to define adequacy, our study included one case (1.6%) of a misinterpreted FNA with a subsequent, biopsyproven infiltrating ductal carcinoma. According to our definition of cellular adequacy, cellular material present on this smear was sufficient to make a suspicious diagnosis.…”

Fine Needle Aspiration of the Breast

“…This empirical observation has recently been substantiated by a study that showed that a significant proportion of breast aspirates may yield false negative results despite "adequate to high" cellularity. 5 Based upon the above rationale, we have specific recommendations for each cytologic diagnostic category. Although definitive treatment was recommended for our positive cases, a preceding confirmation of the malignant diagnosis by frozen section or gross examination is always prudent, especially for nonpalpable breast lesions detected on and sampled under the guidance of mammography, since a significant proportion of carcinomas in these specimens is in situ.…”