Kevin Schofield

The Bethesda thyroid fine-needle aspiration classification system: year 1 at an academic institution.

BACKGROUND Fine-needle aspiration (FNA) may be the procedure of choice in the preoperative evaluation of thyroid nodules, yet it suffers as a modality both because of its inherent limitations as well as variability in its diagnostic terminology. The National Cancer Institute recently proposed a classification system. The objective of this study was to report our experience in using this new reporting system to review the distribution of diagnosis categories and to evaluate the specificity of the system based on the cytologic-histologic correlation. PATIENTS AND METHODS A total of 3207 thyroid nodules underwent FNA, that is, 3207 FNAs from 2468 patients were examined at our institution between January 1, 2008 and December 31, 2008. All FNAs were classified prospectively into unsatisfactory, benign, indeterminate (cells of undetermined significance), follicular neoplasm (FN), suspicious for malignancy, and positive for malignancy. RESULTS The distribution of these categories from 3207 evaluated nodules was as follows: 11.1% unsatisfactory, 73.8% benign, 3.0% indeterminate, 5.5% FN, 1.3% suspicious, and 5.2% malignant. Of the 2468 sampled patients, 378 (15%) underwent thyroidectomy. The distribution of diagnoses of patients who underwent surgery was as follows: 10% unsatisfactory, 4.6% benign, 30.3% indeterminate, 61.4% FN, 76.9% suspicious, and 77.2% malignant. There was an excellent association between the categories and in predicting benign versus malignant thyroid nodules (p < 0.0001). However, the false-negative rate cannot be calculated because only a small number of patients with benign diagnosis underwent surgery. The false-positive rate was 2.2%; all were diagnosed as suspicious cytologically. Given that only 15% of the patients underwent surgery, at this time the sensitivity of thyroid FNA for diagnosing malignant thyroid nodules cannot be calculated, nor can the sensitivity of thyroid FNA as a screening test for all neoplasms be accurately estimated. The specificity for diagnosing malignant thyroid nodules was 93%, whereas the specificity as a screening test for all neoplasms was 68%. The positive predictive values for an FN, suspicious, and positive cytologic diagnosis were 34%, 87%, and 100%, respectively. CONCLUSIONS These data demonstrate that the recently proposed classification system is excellent for reporting thyroid FNAs. Each diagnostic category conveys specific risks of malignancy, which offers guidance for patient management.

Distinct human papillomavirus type 16 methylomes in cervical cells at different stages of premalignancy.

Human papillomavirus (HPV) gene expression is dramatically altered during cervical carcinogenesis. Because dysregulated genes frequently show abnormal patterns of DNA methylation, we hypothesized that comprehensive mapping of the HPV methylomes in cervical samples at different stages of progression would reveal patterns of clinical significance. To test this hypothesis, thirteen HPV16-positive samples were obtained from women undergoing routine cervical cancer screening. Complete methylation data were obtained for 98.7% of the HPV16 CpGs in all samples by bisulfite-sequencing. Most HPV16 CpGs were unmethylated or methylated in only one sample. The other CpGs were methylated at levels ranging from 11% to 100% of the HPV16 copies per sample. The results showed three major patterns and two variants of one pattern. The patterns showed minimal or no methylation (A), low level methylation in the E1 and E6 genes (B), and high level methylation at many CpGs in the E5/L2/L1 region (C). Generally, pattern A was associated with negative cytology, pattern B with low-grade lesions, and pattern C with high-grade lesions. The severity of the cervical lesions was then ranked by the HPV16 DNA methylation patterns and, independently, by the pathologic diagnoses. Statistical analysis of the two rating methods showed highly significant agreement. In conclusion, analysis of the HPV16 DNA methylomes in clinical samples of cervical cells led to the identification of distinct methylation patterns which, after validation in larger studies, could have potential utility as biomarkers of neoplastic cervical progression.

Thyroid follicular lesion of undetermined significance: Evaluation of the risk of malignancy using the two-tier sub-classification

The Bethesda 2007 Thyroid Cytology Classification defines follicular lesion of undetermined significance as a heterogeneous category of cases that are not convincingly benign nor sufficiently atypical for a diagnosis of follicular neoplasm or suspicious for malignancy. In our institution, we refer to these cases as indeterminate, and they are further sub‐classified into two: (1) low cellularity with predominant microfollicular architecture and absence of colloid (INa) and (2) nuclear features not characteristic of benign lesions (nuclear atypia) (INb). We reviewed these indeterminate cases to document the follow‐up trend using this two‐tier classification. A search of the cytology records was performed for the period between January 2008 and June 2009. All thyroid fine‐needle aspiration (FNA) cases were reviewed and the ones diagnosed as indeterminate were identified. Correlating follow‐up FNA and/or surgical pathology reports were reviewed. The percentage of cases showing a malignancy was calculated. One hundred and seventy‐one indeterminate cases were identified, representing 2.8% of the 6,205 thyroid FNA cases examined during the time under review (107 INa, 64 INb). Records of follow‐up procedures were available in 106 (61%) cases. Malignancy was identified in 27% of all indeterminate cases. This was disproportionately more in the INb (56%) compared to the INa (7%) cases. A diagnosis of “INa” does not carry the same implication as that of “INb”. The INb category needs a more aggressive follow‐up than the INa category and may justify an immediate referral for lobectomy. Despite the vague morphologic criteria for this diagnostic category, the indeterminate rate remains relatively low and falls within the NCI recommendation (<7%). Diagn. Cytopathol. 2011;.

BRAF Mutation Testing of Thyroid Fine-Needle Aspiration Specimens Enhances the Predictability of Malignancy in Thyroid Follicular Lesions of Undetermined Significance

Background/Objective: The Bethesda 2007 Thyroid Cytology Classification defines atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) as a heterogeneous category of cases that are neither convincingly benign nor sufficiently atypical for a diagnosis of follicular neoplasm or suspicious for malignancy. At our institution, we refer to these cases as ‘indeterminate’ and they are further subclassified into two categories. BRAF mutation occurs in 40–60% of papillary thyroid carcinoma (PTC). In this study, we examined cases in the AUS/FLUS category in correlation with BRAF mutation analysis and surgical pathology outcome. Study Design: Thyroid fine-needle aspiration (FNA) cytology specimens interpreted as ‘indeterminate’ were selected from our files, and available remnants of thin-layer processed specimens were used for BRAF mutation analysis. Surgical pathology reports were reviewed for the final outcomes in these patients. Results: Of the 84 indeterminate cases with BRAF mutation analysis, only 49 had follow-up with surgical intervention. Sixteen cases had BRAF mutation. All of the BRAF-positive cases had a final diagnosis of PTC. Conclusions: The sensitivity and specificity of BRAF mutation in detecting PTC in FNA specimens with indeterminate diagnosis was 59.3 and 100%, respectively, while the positive and negative predictive values were 100 and 65.6%, respectively. The limited data supports the use of BRAF mutation analysis to predict the risk of malignancy in patients with indeterminate thyroid FNAs.

Use of magnetic enrichment for detection of carcinoma cells in fluid specimens

Ascites fluid or a pleural effusion are common events in metastatic carcinoma, but they also can be associated with several other medical conditions. The standard for determination of malignancy in these situations is cytologic evaluation of these fluids. Although this method is frequently successful, there are times when it fails, even when the patient has a malignancy, either because of insufficient cells in the fluid or for other reasons. This study addresses this problem taking advantage of the recent advances in technology for detection of rare epithelial cells in liquid specimens.

The cell adhesion molecule, E‐cadherin, distinguishes mesothelial cells from carcinoma cells in fluids

The distinction between benign reactive mesothelial cells and well differentiated carcinoma can be difficult in pleural, peritoneal, and especially pericardial fluids. E‐cadherin is an adhesion protein that is specifically expressed in cells of epithelial lineage. In this study, anti‐E‐cadherin antibodies were used to identify and distinguish carcinoma cells from reactive mesothelial cells.

Comparison of Affirm VPIII and Papanicolaou Tests in the Detection of Infectious Vaginitis

To compare the Affirm VPIII molecular test (Becton Dickinson, Burlington, NC) with morphologic identification used in routine Papanicolaou (Pap) test screening in the detection and identification of Candida species, Trichomonas vaginalis, and Gardnerella vaginalis, we identified 431 cases with a concomitant Pap test and Affirm VPIII assay performed from the archives of a large academic institution. The study population consisted of women ranging in age from 17 to 79 years (mean and median ages, 33 and 31 years, respectively). With a routine Pap test, 60 patients (13.9%) were found to have bacterial vaginosis, 60 (13.9%) candidiasis, and 3 (0.7%) Trichomonas infection. With the Affirm VPIII assay, 183 (42.5%) patients tested positive for G vaginalis, 70 (16.2%) positive for Candida species, and 10 (2.3%) positive for T vaginalis. The differences were statistically significant. The results demonstrate that our patient population had a high incidence of bacterial vaginosis/Candida vaginitis; however, the Affirm VPIII was a more sensitive diagnostic test for the detection and identification of all 3 organisms compared with the Pap test.

A Comparison of the Roche Cobas HPV Test With the Hybrid Capture 2 Test for the Detection of High-Risk Human Papillomavirus Genotypes

CONTEXT All Food and Drug Administration-approved methods in the United States for human papillomavirus testing including the Hybrid Capture 2 human papillomavirus assay and the Roche cobas human papillomavirus test are approved for cytology specimens collected into ThinPrep media but not for specimens collected into SurePath solution. OBJECTIVE To compare the performance of the Roche cobas and Hybrid Capture 2 tests for the detection of high-risk human papillomavirus using both ThinPrep and SurePath preparations as part of a validation study. DESIGN One thousand three hundred seventy-one liquid-based cytology samples, including 1122 SurePath and 249 ThinPrep specimens, were tested for high-risk human papillomavirus DNA using the Roche cobas human papillomavirus test and the Hybrid Capture 2 human papillomavirus assay. For cases with discrepant results, confirmatory testing was performed using Linear Array human papillomavirus testing. RESULTS One hundred and fifty-six (11.38%) and 184 (13.42%) of the 1371 specimens tested positive for high-risk human papillomavirus DNA using the Hybrid Capture 2 human papillomavirus assay and Roche cobas human papillomavirus assay, respectively. In addition, 1289 (94.0%) of 1371 specimens demonstrated concordant high-risk human papillomavirus results with a κ value of 0.72 (95% confidence interval, 065-0.78). There was no statistically significant difference in the percentage of positive high-risk human papillomavirus results between the 2 liquid-based preparations with either assay. Discordant results between the 2 assays were noted in 82 of 1371 cases (6%). Twenty-seven of 82 cases (32.9%) were Hybrid Capture 2 positive/Roche cobas negative and 55 of 82 cases (67.1%) were Roche cobas positive/Hybrid Capture 2 negative. Two of 20 Hybrid Capture 2-positive/Roche cobas-negative cases (10%) and 26 of 37 Roche cobas-positive/Hybrid Capture 2-negative cases (70%) tested positive for high-risk human papillomavirus by Linear Array. CONCLUSIONS Both assays showed good agreement and excellent specificity with either ThinPrep or SurePath preparations. The number of discordant results was relatively small. The performance of both assays was similar for ThinPrep specimens, but the Roche cobas test demonstrated higher sensitivity with SurePath specimens.

Use of High-Risk Human Papillomavirus Testing in Patients With Low-Grade Squamous Intraepithelial Lesions

The role of testing for high‐risk human papillomavirus (HR HPV) when triaging women with a cytologic diagnosis of low‐grade squamous intraepithelial lesion (LSIL) has not been well established. The objective of the current study was to correlate the status of HR HPV with the incidence of cervical intraepithelial neoplasia 2 and more severe lesions (CIN 2+) on tissue follow‐up in women with LSIL.

Implementation of FocalPoint GS location-guided imaging system: experience in a clinical setting.

Recently, the Food and Drug Administration approved the use of the location‐guided imaging system FocalPoint GS (FPGS), on SurePath Papanicolaou (Pap) tests for primary screening. The objective of the current study was to evaluate the impact of FPGS on the following: distribution of diagnostic categories; rate of high‐risk human papillomavirus (HR‐HPV)–positive ASC‐US cases; and quality control (QC) data before and after FPGS implementation.