Atypical Fine-needle Aspiration Research Articles

Thyroid Fine-Needle Aspiration<subtitle>Does Case Volume Affect Diagnostic Yield and Interpretation?</subtitle>

To evaluate the effect of case volume on the diagnostic yield and interpretation of thyroid fine-needle aspiration (FNA). Retrospective case series. An academic tertiary referral center and 2 community hospital centers. Data were retrospectively reviewed for all consecutive patients undergoing thyroid FNA at these institutions during the 2009 calendar year. Differences in diagnostic distribution and yield among pathologists and clinicians of differing case volume. A total of 790 patients underwent thyroid FNA, with the results interpreted as benign (479 [60%]), atypical (166 [22%]), malignant (9 [1%]), or nondiagnostic (136 [17%]). The FNAs were performed by 134 physicians and interpreted by 16 pathologists with varying case volumes. Low-volume pathologists (<50 FNAs interpreted) were more likely to report atypical FNAs (32% vs 13%; P<.001) and less likely to call FNAs benign (50% vs 70%; P<.001) compared with high-volume pathologists (≥50 FNAs interpreted), and compared with expected normative data (benign, P<.001; atypical, P<.001). Atypical FNA findings reported by low-volume pathologist were more likely to yield benign permanent results than those read by high-volume pathologists (64% vs 42%; P<.02). Low-volume clinicians (<20 FNAs performed) were not more likely to perform nondiagnostic FNAs compared with high-volume clinicians (≥20 FNAs performed) (16% vs 15%; P=.47). Case volume significantly influences the pathologic interpretation of thyroid FNA, as low-volume pathologists report more atypical and fewer benign FNA results. Case volume did not have a significant impact on diagnostic yield, because thyroid FNAs performed by low-volume clinicians did not result in more frequent nondiagnostic results compared with those performed by high-volume clinicians.

Fluorescence In Situ Hybridization and K-ras Analyses Improve Diagnostic Yield of Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Solid Pancreatic Masses

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is the main diagnostic modality for pancreatic mass lesions. However, cytology is often indeterminate, leading to repeat FNAs and delay in care. Here, we evaluate whether combining routine cytology with fluorescence in situ hybridization (FISH) and K-ras/p53 analyses improves diagnostic yield of pancreatic EUS-FNA. Fifty EUS-FNAs of pancreatic masses in 46 patients were retrospectively analyzed. Mean follow-up was 68 months. Thirteen initial cytologic samples (26%) were benign, 23 malignant (46%), and 14 atypical (28%). We performed FISH for p16, p53, LPL, c-Myc, MALT1, topoisomerase 2/human epidermal growth factor receptor 2, and EGFR, as well as K-ras/p53 mutational analyses. On final diagnosis, 11 (79%) of atypical FNAs were malignant, and 3 benign (21%). Fluorescence in situ hybridization was negative in all benign and all atypical samples with final benign diagnosis. Fluorescence in situ hybridization plus K-ras analysis correctly identified 60% of atypical FNAs with final malignant diagnosis. Combination of routine cytology with positive FISH and K-ras analyses yielded 87.9% sensitivity, 93.8% specificity, 96.7% positive predictive value, 78.9% negative predictive value, and 89.8% accuracy. Combining routine cytology with FISH and K-ras analyses improves diagnostic yield of EUS-FNA of solid pancreatic masses. We propose to include these ancillary tests in the workup of atypical cytology from pancreatic EUS-FNA.

Thyroid Bed Fine-Needle Aspiration

Fine-needle aspiration (FNA) of thyroid bed (TB) lesions is a common diagnostic modality in monitoring patients for recurrent cancer after a thyroidectomy. To elucidate the value of TB FNA, we reviewed our experience at The Johns Hopkins Hospital, Baltimore, MD. We identified 57 TB FNA specimens from 50 patients. Of the patients, 36 were being followed up for papillary carcinoma, 7 for medullary carcinoma, 4 for follicular carcinoma (1 also had papillary carcinoma), and 1 for poorly differentiated neuroendocrine carcinoma; 3 had previous benign diagnoses. TB FNA yielded diagnostic material in 49 of 57 cases. Of 37 malignant or atypical FNA samples, 32 had surgical follow-up; 30 of 32 were confirmed malignant. The FNA result was benign in 12 of 57, including 6 cases of benign thyroid and 1 case of parathyroid tissue. Immunohistochemical staining was contributory in 5 of 57 cases. TB FNA is a highly reliable tool for diagnosing recurrent thyroid carcinoma. Residual benign thyroid and parathyroid tissue are potential pitfalls; awareness of these and judicious use of immunohistochemical staining can prevent misdiagnoses.

Immunohistochemical Analysis Increases the Yield of Nondiagnostic EUS-Guided Pancreatic FNA

Background and Aims: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) has emerged as a main diagnostic modality of pancreatic lesions. FNA pathology results are usually reported as benign, malignant or atypical cells. Atypical cells diagnosis leads to repeated FNAs and ultimately to delay in care. The aim of the study was to evaluate the incidence and long-term outcome of atypical cells diagnosis by EUS-FNA of solid pancreatic masses done in two institutional settings (tertiary academic center and community hospital). Secondly, the aim was to determine if the diagnostic yield can be improved by immunohistochemical staining for various tumor markers. Methods: 225 solid pancreatic mass EUS-FNAs from 2001-2008 were retrospectively reviewed; 151 were done at a tertiary academic medical center (group 1) and 74, at a community hospital (group 2). All EUS-FNAs were performed by two endoscopists (VE and DC) with extensive EUS experience. All pathological diagnosis in group 1 was made by two pathologists (RV and SF); in group 2, one cytopathologist reviewed all EUS-FNAs and the atypical specimens were sent out for second opinion. The final diagnosis was based on clinical follow-up and/or pathology specimens obtained endoscopically, surgically or post-mortem. Results: In group 1, cytology was 49 atypical (32%), 63 malignant (42%), 28 benign (19%), and 11 insufficient for diagnosis (7%). Of the atypicals in this group, 33 (67%) were later determined to be malignant. In group 2, 29 (39%) had atypical diagnosis, 25 (34%) were malignant, and 20 (27%) benign. Of the 29 atypicals, 17 (59%) were diagnosed malignant on long-term follow up. Sensitivity for malignancy in group 1 was 62% if the atypicals were considered benign, and 96% if atypicals were considered malignant; specificity was 100% and 77%, respectively. For group 2, sensitivity was 52% if the atypicals were considered benign, and 88% if malignant, with specificity of 100% and 54%, respectively. Immunohistochemical staining for CEA, p53, MIB, CA 19-9, CAM 5.2 was performed on 69 FNAs from group 1. Adding at least one immunohistochemical marker to routine cytology increased the sensitivity from 62% to 85%. In 24 atypical specimens (from the total 49), diagnosis was changed to malignant after the immunohistochemical analysis. Conclusions: Our results suggest that atypical cell diagnosis is fairly common in both academic and community settings. Immunohistochemical staining improves the yield of EUS-FNA of solid pancreatic masses and should be considered for routine use. The majority of atypical FNAs were finally diagnosed malignant, thus necessitating a close follow up and further testing.

Fine‐needle aspiration cytology of apocrine adenosis of the breast: Report on three cases

Apocrine adenosis is a distinctive breast lesion, which can sometimes be misdiagnosed as malignant histologically. Although its histological characteristics have been well established, there are limited descriptions of its cytological features. We report fine-needle aspiration (FNA) cytology of three cases of apocrine adenosis. There were diverse cytological features between cases, and in two cases, FNA smears were highly cellular. Naked nuclei were present in all cases, and were numerous in one. Enlarged nucleoli and anisonucleosis were common. Apocrine metaplasia with nuclear atypia mimicking apocrine carcinoma was prominent in one case, whereas one case lacked definite apocrine features. Regardless of their various atypical FNA cytologies, the nuclei were consistently less hyperchromatic in all cases. Although FNA cytology of apocrine adenosis has the potential to be misinterpreted as malignant, the naked nuclei of background and less hyperchromatic nuclear features may be useful in distinguishing apocrine adenosis from carcinoma. Being familiar with these distinctive breast lesions is also important in decreasing false positives.