The utility of the Milan System as a risk stratification tool for salivary gland fine needle aspiration cytology specimens.

OBJECTIVE: To perform a retrospective investigation of our institutional experience with salivary gland fine needle aspirations (FNA) through the framework of The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) and assess the risks of neoplasm and malignancy for each diagnostic category. METHODS: All salivary gland FNAs performed from January 2009 to December 2016 were retrospectively categorised according to the MSRSGC. When available, pre-operative cytological results were correlated with subsequent histological follow-up. RESULTS: In total, 893 FNAs were reviewed. The specimens were retrospectively classified as nondiagnostic (ND: 13.5%), non-neoplastic (NN: 16.1%), atypia of undetermined significance (AUS: 10.8%), benign neoplasm (BN: 34.9%), salivary gland neoplasm of uncertain malignant potential (SUMP: 8.2%), suspicious for malignancy (SM: 2.7%) and malignant (M: 13.8%). Histological follow-up was available for 429 cases (48%); the majority (68.1%) were benign. The risks of neoplasm and malignancy for each category were as follows: ND: 64.5%, 16.1%; NN: 42.9%, 17.9%; AUS: 79.6%, 30.6%; BN: 100%, 2.2%; SUMP: 100%, 46.6%; SM: 94.7%, 78.9%; and M: 100%, 98.5%. CONCLUSIONS: The MSRSGC is a useful classification scheme for stratifying salivary gland lesions according to their associated risk of malignancy and guiding clinicians toward appropriate management. Diagnostic pitfalls are seen in a small proportion of cases and a multidisciplinary approach for assessing salivary gland pathology is essential in their evaluation.

Usage trends and performance characteristics of a "gene expression classifier" in the management of thyroid nodules: An institutional experience.

BACKGROUND: The gene expression classifier (GEC; Afirma-Veracyte) has proven to be an effective triage modality in the management of thyroid nodules. We evaluate our institutional experience with GEC, specifically examining performance as a first line testing strategy versus in conjunction with repeat fine needle aspiration (FNA), usage trends based on clinical setting, and performance related to diagnostic categories of The Bethesda System for Reporting Thyroid Cytology (TBSRTC). METHODS: All nodules undergoing GEC analysis from 1/2011 to 12/2015 at the Hospital of the University of Pennsylvania were identified using electronic database search methods. Corresponding cytologic diagnoses, GEC results, origin of the sample (in-house vs. satellite site), number and diagnosis of prior FNA's, and clinical and histologic follow-up were collected. RESULTS: The cohort included 294 nodules. Of these, 145 (49%) were classified as benign, 136 (46%) as suspicious, and 13 (5%) as quantity insufficient by GEC. Surgical resection was performed in 130 (130/294-44%) cases (107, 82% "suspicious" by GEC); final histopathologic diagnosis was benign in 85 (65%) and malignant in 45 (35%) cases. Three false negative diagnoses were identified in the setting of GEC analysis as a first line testing strategy. Most cases with GEC as a first line testing strategy came from satellite clinical sites (112, 66%). CONCLUSIONS: The GEC showed improved performance characteristics when coupled with a repeat FNA. It continues to be of low specificity and positive predictive value in oncocytic follicular lesions. Diagn. Cytopathol. 2016;44:867-873. © 2016 Wiley Periodicals, Inc.

The impact of FNAC in the management of salivary gland lesions: Institutional experiences leading to a risk-based classification scheme.

BACKGROUND: Fine-needle aspiration cytology (FNAC) has proven its value as an essential step in the diagnosis of salivary gland lesions. Although the majority of salivary gland lesions, especially those that are common and benign, can be diagnosed with ease on FNAC, limited cellularity and morphologic lesion heterogeneity can pose diagnostic challenges and lead to false-positive and false-negative diagnoses. This study presents the institutional experience of FNAC of salivary gland lesions from 2 academic centers. METHODS: A retrospective analysis was conducted on 1729 salivary gland FNAC specimens that were diagnosed over an 8-year period from January 2008 to March 2015. All samples were processed either with liquid-based cytology alone or in combination with air-dried, Diff-Quik-stained or alcohol-fixed, Papanicolaou-stained smears. RESULTS: Surgical excision was performed in 709 of 1749 FNACs (41%) that were diagnosed as nondiagnostic/inadequate (n = 29), benign (n = 111), neoplasm (n = 453), atypical (n = 15), suspicious for malignancy (n = 28), and malignant (n = 73). The overall concordance between cytologic and histologic diagnoses was 92.2%, with 91.8% concordance in the benign category and 89.5% concordance in cases diagnosed as suspicious for malignancy and malignant. The most frequent benign and malignant lesions were pleomorphic adenoma and squamous cell carcinoma, respectively. There were 46 false-negative and 13 false-positive results, leading to an overall specificity of 97.6% and diagnostic accuracy of 91.3%. CONCLUSIONS: FNAC is a reliable diagnostic modality for the diagnosis and management of salivary gland lesions based on its high specificity and diagnostic accuracy. Cancer Cytopathol 2016;124:388-96. © 2016 American Cancer Society.

Impact of reclassifying noninvasive follicular variant of papillary thyroid carcinoma on the risk of malignancy in The Bethesda System for Reporting Thyroid Cytopathology.

BACKGROUND: Recent discussions have focused on redefining noninvasive follicular variant of papillary thyroid carcinoma (NI-FVPTC) as a neoplasm rather than a carcinoma. This study assesses the potential impact of such a reclassification on the implied risk of malignancy (ROM) for the diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). METHODS: The study consisted of consecutive fine-needle aspiration biopsy (FNAB) cases collected between January 1, 2013 and June 30, 2014 from 5 academic institutions. Demographic information, cytology diagnoses, and surgical pathology follow-up were recorded. The ROM was calculated with and without NI-FVPTC and was presented as a range: all cases (ie, overall risk of malignancy [OROM]) versus those with surgical follow-up only. RESULTS: The FNAB cohort consisted of 6943 thyroid nodules representing 5179 women and 1409 men with an average age of 54 years (range, 9-94 years). The combined average ROM and OROM for the diagnostic categories of TBSRTC were as follows: nondiagnostic, 4.4% to 25.3%; benign, 0.9% to 9.3%; atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 12.1% to 31.2%; follicular neoplasm (FN), 21.8% to 33.2%; suspicious for malignancy (SM), 62.1% to 82.6%; and malignant, 75.9% to 99.1%. The impact of reclassifying NI-FVPTC on the ROM and OROM was most pronounced and statistically significant in the 3 indeterminate categories: the AUS/FLUS category had a decrease of 5.2% to 13.6%, the FN category had a decrease of 9.9% to 15.1%, and the SM category had a decrease of 17.6% to 23.4% (P < .05), whereas the benign and malignant categories had decreases of 0.3% to 3.5% and 2.5% to 3.3%, respectfully. The trend of the effect on the ROM and OROM was similar for all 5 institutions. CONCLUSIONS: The results from this multi-institutional cohort indicate that the reclassification of NI-FVPTC will have a significant impact on the ROM for the 3 indeterminate categories of TBSRTC.

Diagnosis of atypia/follicular lesion of undetermined significance: An institutional experience.

BACKGROUND: The overall malignancy rate for the thyroid fine-needle aspiration (FNA) diagnosed as atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) ranges from 5% to 30%. In this study, we present our institutional experience with thyroid nodules diagnosed as AUS/FLUS and further stratified into subcategories. In addition, we also assessed the significance of various clinicopathologic factors that may influence AUS/FLUS diagnoses and their outcomes. DESIGN: A search of our laboratory information system was performed to identify all in-house thyroid FNA cases diagnosed as AUS/FLUS from 2008 to 2012. The data were collected and characterized by patient demographic information, cytopathology diagnosis with sub-classifiers and follow-up. RESULTS: The case cohort included 457 cases diagnosed as AUS/FLUS. These were further sub-classified into one of six subcategories depending on the cytomorphologic findings and suspicion for or against a neoplastic process. Of the 457 cases, repeat FNA and/or surgical follow-up was available in 363 cases. There were 182 (39.8%) cases with cytologic follow-up only; 18 (9.9%) remained as AUS/FLUS, while 158 (86.8%) were re-classified with the majority being benign (142 cases). Histologic follow-up was available in 181 (39.6%) cases. There were 60 malignant cases confirmed by surgical excision, with an overall malignancy rate of 33.1%. The malignancy rate was 38.8% for cases with a repeat FNA versus 25.6% for cases that went directly to surgery without a repeat FNA. Papillary thyroid carcinoma accounted for 93.3% (56 cases) of the malignant cases. CONCLUSION: Based on our study, even though the malignancy rate of AUS/FLUS cases is similar to those reported for cases diagnosed as follicular neoplasm/suspicious for follicular neoplasm, we are of the belief that these comparable malignancy rates are a product of better clinical management and selection of patients diagnosed as AUS/FLUS for surgery after a repeat FNA.

Analysis of the bethesda system for reporting thyroid cytopathology and similar precursor thyroid cytopathology reporting schemes.

The Bethesda System for Reporting Thyroid Cytopathology is a standardized reporting system for classifying thyroid fine-needle aspiration results comprising of 6 diagnostic categories with unique risks of malignancy and recommendations for clinical management. The majority of thyroid nodules are benign; however, up to 30% of fine-needle aspiration of thyroid nodule results are equivocal. Until 2007, various diagnostic terms were used to classify such cases, including "atypical," "indeterminate," and rule-out or cannot exclude malignancy. A literature review of 13 original studies was conducted to evaluate whether utilization of the Bethesda System for Reporting Thyroid Cytopathology nomenclature represent an improvement over thyroid cytopathology reporting schemes used before 2007 in diagnosing thyroid malignancy. The sensitivity and specificity of thyroid fine-needle aspiration was high in the studies that assessed the measures. However, a selection bias exists and most studies do not include indeterminate diagnosis in their calculations. Although the Bethesda System for Reporting Thyroid Cytopathology recommends a repeat fine-needle aspiration to follow-up nondiagnostic specimens, in the majority of studies, an appreciable number of cases underwent follow-up surgical biopsy or thyroidectomy. The diagnostic category of atypia/follicular lesion of undetermined significance remains heterogenous in terms of usage and clinical outcome. The majority of the studies that utilize the Bethesda System for Reporting Thyroid Cytopathology in this literature review retrospectively reclassified thyroid fine-needle aspiration into the Bethesda System for Reporting Thyroid Cytopathology nomenclature with reported malignancy rates that are similar between cases reclassified as atypia/follicular lesion of undetermined significance and follicular neoplasm/suspicious for follicular neoplasm.

The SCAN domain mediates selective oligomerization.

The SCAN domain is described as a highly conserved, leucine-rich motif of approximately 60 amino acids found at the amino-terminal end of zinc finger transcription factors. Although no specific biological function has been attributed to the SCAN domain, its predicted amphipathic secondary structure led to the suggestion that this domain may mediate protein-protein associations. A yeast two-hybrid screen identified members of two SCAN domain protein families that interact with the SCAN domain of the zinc finger protein ZNF202. The interacting ZNF191 protein represents the family of SCAN domain-containing zinc finger proteins, whereas the novel SDP1 protein establishes a new family of genes that encode an isolated SCAN domain. Isolated SCAN domain proteins may form asymmetric homodimers in solution. Biochemical binding studies confirmed the associations of ZNF191 and SDP1 with ZNF202 and established the SCAN domain as a selective hetero- and homotypic oligomerization domain. SCAN mediated protein associations might therefore represent a new regulatory mechanism of transcriptional activity.

Characterization of a carboxy-terminal BRCA1 interacting protein.

There are several lines of evidence indicating that the carboxy-terminal region of the tumor suppressor protein BRCA1 is a functionally significant domain. Using the yeast two-hybrid and in vitro biochemical assays, we show that a protein, CtIP, interacts specifically with the carboxy-terminal segment of human BRCA1 from residues 1602-1863. A germ line truncation mutation, Y1853ter, that removes the last 11 amino acids from the carboxy-terminus of BRCA1, abolishes not only its transcriptional activation function, but also binding to CtIP. The function of CtIP is unknown, but its reported association with a transcriptional repressor CtBP lends further support that it may have a role in transcription. A sequence based screen of a panel of 89 tumor cell line cDNAs for mutations in the CtIP coding region identified five missense variants. In the pancreatic carcinoma cell line, BxPC3, the non-conservative lysine to glutamic acid change at codon 337 is accompanied with apparent loss of heterozygosity or non-expression of the wild type allele. Thus it is plausible that CtIP may itself be a tumor suppressor acting in the same pathway as BRCA1.

Mad proteins contain a dominant transcription repression domain.

Transcription repression by the basic region-helix-loop-helix-zipper (bHLHZip) protein Mad1 requires DNA binding as a ternary complex with Max and mSin3A or mSin3B, the mammalian orthologs of the Saccharomyces cerevisiae transcriptional corepressor SIN3. The interaction between Mad1 and mSin3 is mediated by three potential amphipathic alpha-helices: one in the N terminus of Mad (mSin interaction domain, or SID) and two within the second paired amphipathic helix domain (PAH2) of mSin3A. Mutations that alter the structure of the SID inhibit in vitro interaction between Mad and mSin3 and inactivate Mad's transcriptional repression activity. Here we show that a 35-residue region containing the SID represents a dominant repression domain whose activity can be transferred to a heterologous DNA binding region. A fusion protein comprising the Mad1 SID linked to a Ga14 DNA binding domain mediates repression of minimal as well as complex promoters dependent on Ga14 DNA binding sites. In addition, the SID represses the transcriptional activity of linked VP16 and c-Myc transactivation domains. When fused to a full-length c-Myc protein, the Mad1 SID specifically represses both c-Myc's transcriptional and transforming activities. Fusions between the GAL DNA binding domain and full-length mSin3 were also capable of repression. We show that the association between Mad1 and mSin3 is not only dependent on the helical SID but is also dependent on both putative helices of the mSin3 PAH2 region, suggesting that stable interaction requires all three helices. Our results indicate that the SID is necessary and sufficient for transcriptional repression mediated by the Mad protein family and that SID repression is dominant over several distinct transcriptional activators.

Mad-Max transcriptional repression is mediated by ternary complex formation with mammalian homologs of yeast repressor Sin3.

The bHLH-ZIP protein Mad heterodimerizes with Max as a sequence-specific transcriptional repressor. Mad is rapidly induced upon differentiation, and the associated switch from Myc-Max to Mad-Max heterocomplexes seem to repress genes normally activated by Myc-Max. We have identified two related mammalian cDNAs that encode Mad-binding proteins. Both possess sequence homology with the yeast transcription repressor Sin3, including four conserved paired amphipathic helix (PAH) domains. mSin3A and mSin3B bind specifically to Mad and the related protein Mxi1. Mad-Max and mSin3 form ternary complexes in solution that specifically recognize the Mad-Max E box-binding site. Mad-mSin3 association requires PAH2 of mSin3A/mSin3B and the first 25 residues of Mad, which contains a putative amphipathic alpha-helical region. Point mutations in this region eliminate interaction with mSin3 proteins and block Mad transcriptional repression. We suggest that Mad-Max represses transcription by tethering mSin3 to DNA as corepressors and that a transcriptional repression mechanism is conserved from yeast to mammals.