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Malignancy Rates in Bethesda Class III? Do Follicular Lesion of Undetermined Significance (FLUS) and Atypia of Undetermined Significance (AUS) Belong Together?
Abstracts 110 Immunohistochemical Utility of Histone H1.5 and Aquaporin 4 in Assessing Thyroid Lesions in Fine Needle Aspiration Biopsies Sorin Selegean, MD, Yayoi Kinoshita, MD, Maoxin Wu, MD, PhD, Arnold Szporn, MD, David Burstein, MD. Department of Pathology Division of Cytopathology, Mount Sinai School of Medicine, New York, New York Introduction: Cytopathologic examination of thyroid lesions is a common encounter for the practicing pathologist. Immunohistochemical panels to assist in the differential diagnosis of these lesions are not well-defined. Our aim was to assess the immunohistochemical utility of aquaporin 4 (AQP4) and histone H1.5 (H1.5) in distinguishing these lesions. Aquaporins are small membrane bound transport proteins that facilitate osmotically driven water transport. Their immmunohistochemical expression in several type of tumors has been investigated, with AQP4 showing increased expression in tumors of astrocytic origin, and decreased staining in lung and gastric carcinomas. H1.5 is part of the H1 linker histone group which is important in heterochromatin assembly. Histone H1family has been shown to have high immunohistochemical levels in malignancies including breast and lung carcinomas. Materials and Methods: Cell blocks from 20 cases obtained from 18 patients were used, including 4 lymph nodes and 16 thyroid aspirates. The lymph nodes were positive for metastatic papillary carcinoma (3 cases) and medullary carcinoma (1 case). The thyroid specimens included nodular goiter (8 cases), 1 case of atypical follicular lesion with Hurthle cell features, papillary thyroid carcinoma (PTC), classical type (2 cases), follicular variant (2 cases), tall cell variant (1case), anaplastic thyroid carcinoma (1 case), and metastatic renal cell carcinoma (1 case). Monoclonal rabbit antibodies against AQP4 and H1.5 were used in 1:3000 and 1:4000 dilutions, respectively. The staining pattern was evaluated based on location (nuclear for H1.5 versus membranous for AQP4), intensity (four tier, negative to strong) and percentage of positive lesional cells. Results: AQP4 showed basolateral membranous staining, while H1.5 displayed nuclear staining. All 4 cases of lymph node metastases were negative for H1.5 with negativity for AQP4 in 3 cases and weak, focal (<50%) staining in 1 case of papillary carcinoma, classical type. Seven cases of nodular goiters were negative for H1.5 and showed strong and diffuse membranous staining (>90%) with AQP4. One case showed 20% weak staining for H1.5 with AQP4 negativity. The classical type of PTC showed AQP4 negativity and moderate to strong positivity for H1.5 in 80% and 30% of the cells, respectively. The follicular variants were H1.5 negative and showed moderate to weak positivity for AQP4 in 80% and 10%, respectively. The tall cell variant was negative for both. The metastatic renal cell carcinoma stained positively for H1.5 (80%) while being negative for AQP4. The atypical follicular lesion with Hurtle cell features stained identical to majority of the nodular goiters: negative for H1.5 and strong with AQP4. Conclusions: In our study these two markers showed characteristic staining patterns that in most cases separated cellular benign lesions from malignant ones. The majority of benign thyroid lesions are associated with high expression of AQP4 and H1.5 negativity as opposed to classical papillary carcinomas that showed a reverse pattern. These findings suggest diagnostic utility of this combination of markers. Further studies are required to confirm these findings. (Acknowledgement: Supported by a generous bequest from the estate of Hilda Leven) 111 Cytomorphologic Analysis of Anaplastic Thyroid Carcinoma - A Retrospective Study of 60 Cases in a Tertiary Cancer Centre Shubhada Kane1, Gopal Parikh2, Asawari Patil2. 1Cytopathology, Tata Memorial Centre, Mumbai, Maharashtra, India; 2Cytopathology, Tata Memorial Centre, Mumbai, Maharashtra, India Introduction: Anaplastic thyroid carcinoma (ATC) is the most aggressive & lethal form of thyroid cancer. Even though it is a rare thyroid cancer
S65 [1-5%], a definitive diagnosis is warranted as it dictates therapy and defines prognosis. FNAC has greatly improved management of ATC. The cytomorphologic features are specific for diagnosis and easily recognizable. Yet there are few large series in the literature on the role of FNAC. Our study focuses on FNAC as a pretherapy diagnostic modality replacing biopsy in ATC. Materials and Methods: Retrospective analysis was performed of 70 cases reported in 5 years in a tertiary cancer centre on FNAC as ATC or where ATC was included in the differential diagnosis. Cytomorphology was correlated with clinico-radiological features. The 9 diagnostic criteria were hypercellularity, loosely cohesive clusters and isolated cell pattern, large pleomorphic cells with raised N/C ratio, clumped chromatin and prominent nucleoli, abundant cytoplasm, easily identifiable mitosis, necrosis, multinucleated giant cells and inflammatory cells in background. On review, a diagnosis of ATC was retained in 60 cases. Results: Fifty patients presented with a large, rapidly enlarging, unilateral thyroid mass with obstructive symptoms. Only 10 patients presented with a diffuse fixed thyroid mass. All 9 diagnostic criteria were present in 20 [33%] cases. At least 6 criteria were present in 30 [50%] cases. Mitoses and necrosis were observed in 44 [73%] and 35 [58%] cases, respectively. Both features were seen in 25 [41%] cases. Leucophagocytosis a diagnostic clue e was observed in 12 [20%] cases. Predominant spindle cell type was noted in 9 [15%] cases; characterized by elongated hyperchromatic nuclei, insignificant nucleoli, few giant cells and inflammatory cells. Only 6 cases [10%] showed foci of differentiated thyroid carcinoma associated with ATC (3 cases each of papillary and follicular carcinoma). 2 cases of ATC showing papillary carcinoma foci were of spindle cell type; in contrast ATC cases with follicular carcinoma were of pleomorphic type. The diagnosis of ATC was confirmed on biopsy in 12 [20%] cases[4-spindle type, 8-pleomorphic type] where clinico-radiological features were not compatible with ATC or no differential diagnosis was offered on FNAC. In the remaining cases, FNAC diagnosis was compatible with the clinico-radiological diagnosis and treatment was planned accordingly. Conclusions: Definite diagnosis of ATC is reasonably attained on FNAC even though the differential diagnosis is quite wide. Poorly differentiated squamous carcinoma; the most common differential diagnosis; can be distinguished as these lack significant pleomorphism, multinucleated cells, prominent nucleoli, necrosis and inflammatory cells. Other differential diagnoses include medullary carcinoma and Hurthle cell carcinoma which can be differentiated by adhering to specific diagnostic criteria. Immunocytochemistry is necessary in a few cases to establish the correct diagnosis. FNAC is thus the method of choice for making a quick, cost effective, easy and reliable diagnosis of ATC. A confident diagnosis on FNAC obviates the need for biopsy/ surgery resulting in prompt planning of multimodal therapy. 112 Malignancy Rates in Bethesda Class III? Do Follicular Lesion of Undetermined Significance (FLUS) and Atypia of Undetermined Significance (AUS) Belong Together? Alexander Finkelstein, DO, MD, Fang Zhou, MD, Oliver Szeto, MD, Aylin Simsir, MD. Pathology, New York University School of Medicine, New York, New York Introduction: In 2007, a National Cancer Institute (NCI) sponsored consensus conference developed a unified “Bethesda Terminology System (BTS)” for reporting thyroid FNA diagnoses. The TBS places FLUS and AUS within the same category designated as Class III. Based on the TBS data, malignancy rate in this class ranges from 5 to 15% on surgical resection. However, studies published since 2007, including data from our institution, report markedly variable malignancy rates, ranging from 2 to 48%, suggesting that FLUS/AUS is not a homogeneous category. Morphologically FLUS is defined as predominance of a microfollicular pattern that does not otherwise fulfill the criteria for follicular neoplasm; whereas AUS refers more to the presence of nuclear atypia raising concern for papillary thyroid carcinoma (PTC). We sought to determine whether the malignancy rates in
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FLUS (microfollicular pattern) and AUS (nuclear atypia) are similar, and whether they should both be placed in Class III as currently recommended. Materials and Methods: The Pathology department database was queried to retrieve all thyroid FNA samples from January 1, 2010 to December 31, 2011. Surgical follow up diagnoses were reviewed for Class III (FLUS and AUS). Class III was divided into two groups; FLUS for cases with microfollicular pattern falling short of a definitive diagnosis of follicular neoplasm, and AUS for cases with nuclear atypia such as focal nuclear clearing, overlapping, enlargement and occasional grooves. The malignancy rates in each diagnostic group were calculated. Statistical analysis was performed using Pearson Chi-square analysis. Results: There were a total of 6701 specimens from 4647 patients. Of 239 FLUS/AUS cases, 95 (40%) had surgical follow up. The overall FLUS/ AUS rate was 3.6% with a FLUS/AUS to malignant ratio of 0.7. Of 95 FLUS/AUS cases with surgical follow up, 65 were FLUS and 30 AUS. Of the 65 FLUS cases, 23 (35.4%) had PTC on resection; 12 of the PTC cases were the follicular variant (FVPTC). 7 (10.8%) cases were follicular carcinoma, 16 (24.6%) were follicular adenoma, and 19 (29.2%) were nodular hyperplasia. Of 30 AUS cases, 24 (80%) were PTC, with 7 cases of FVPTC; 1 was (3.3%) a poorly differentiated follicular carcinoma, 2 (6.7%) were follicular adenoma, and 3 (10%) were nodular hyperplasia. The differences in the rates of PTC and follicular neoplasms were statistically significant (p value of 0.001) between the AUS and FLUS categories.
these, 9 cases were stage pT1N1, 6 pT1N2 and 53 pT1N0. In every specimen a representative tissue section containing both normal and tumor tissue was analyzed. The expression level for each antibody was evaluated as negative, mild, moderate and strong using a score system that takes into account the percentage of positive tumor cells as well as the intensity of staining. Results: Only a few scattered normal thyroid follicular cells showed mild expression of KiSS-1 and KISS1R. Strong immunoreactivity for KiSS-1 and KISS1R was detected in 90,3% and 80,1% cases with lymph node metastasis, respectively. Smaller PTCs confined within the thyroid gland showed lower levels of expression for both antibodies (42,1% and 24,6% respectively). Conclusions: Our data show an overexpression of KiSS-1 and KISS1R in papillary thyroid carcinomas compared with normal tissue. Our findings also indicate that there is a correlation between KiSS-1 and KISS1R expression and advanced stage of PTC. Taken together these first data suggest that despite the reported antimetastatic effect of KiSS-1 overexpression in various tumors, in the thyroid gland the transcription of KiSS-1 and/or KISS1R genes may play a role in modulating the biological behavior of thyroid cells, so that they acquire metastatic potential. Additional studies in larger series should help to further clarify this issue.
Follow-up Surgical Diagnoses in AUS and FLUS Cases
BRAF V600E on Fine Needle Aspiration: A Poor Test for Modifying Surgical Management in Classical Papillary Thyroid Carcinoma
Total Nodular Follicular Papillary Follicular Poorly Hypeplasia Adenoma Carcinoma Carcinoma Differentiated Carcinoma AUS 3 (10%) FLUS 19 (29%) Class III 22 (23%) Combined
2 (6.7%) 24 (80%) 16 (25%) 23 (35%) 18 (19%) 47 (49%)
0 7 (11%) 7 (7%)
1 (3.3%) 0 1 (1%)
30 65 95
Conclusions: The overall rate of malignancy in Class III in our laboratory is higher than that generally reported. There is a marked difference in the malignancy rate between FLUS and AUS confirming that Class III is a heterogeneous group. The incidence of PTC in AUS cases is significantly higher than in FLUS cases (80% versus 35%). On the other hand, follicular neoplasms are more frequent in cases of FLUS compared to AUS (36% versus 6.7%). Our findings suggest that nuclear atypia carries more significance than microfollicular pattern in prediction of malignancy in the indeterminate nodules (Class III). The overall high rate of malignancy in our study may be a result of multiple factors such as patient selection bias for surgical treatment based on other clinical findings (suspicious radiology, single nodule, etc) and the higher institutional threshold for placing cases in an indeterminate category. 113 Immunohistochemical Study of KiSS-1 and KISS1R Expression in Papillary Thyroid Carcinoma Ekaterini Politi, MD, PhD, Antonia Kapoula, MD, Helen Koutselini, MD, FIAC. Cytopathology Department, Aretaieio University Hospital, Athens, Greece Introduction: KiSS-1 and its G-protein coupled receptor (KISS1R) constitute a biological system involved in the regulation of GnRH release and have been reported to play a metastasis suppression role in various human malignancies. The expression profile of these two genes and its correlation with tumor progression has been slightly studied in thyroid tumors and especially papillary thyroid carcinoma (PTC). In spite of low mortality rates and overall favorable prognosis of PTCs, the worldwide incidence is high and increasing, especially among young adults. The aim of our study was to investigate the expression of KiSS-1 and KISS1R in PTCs and to correlate it with tumor stage and lymph node metastasis. Materials and Methods: Tumor samples from 69 patients with PTC were immunostained using antibodies against KiSS-1 and KISS1R. Among
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Kelly Gilliland, DO, Hui-Jia Dong, PhD, Larry Fowler, MD. Pathology, University of Florida, Gainesville, Florida Introduction: Papillary thyroid carcinomas (PTC) represent the majority of malignant thyroid neoplasms. Recent studies have identified a mutation of the BRAF gene (BRAFV600E) in a large number of PTC. This mutation has been suggested to be associated with a more aggressive behavior and worse outcome in some studies. Many of these studies have included all variants including the follicular variant of papillary which is known to have a better prognosis and is BRAF wild-type. We proposed to determine BRAF expression in a limited population of only classical papillary carcinoma to elucidate the predictability of BRAF mutational presence with its’ associated prognosis. Additionally, we attempted a relatively new technique of using cytology fine needle aspirate specimens to determine the practicality of mutational analysis, as had been recommended by several publications promoting its use to determine a more aggressive surgical approach when the tumor is BRAF mutated. Materials and Methods: Our study reviewed cases of classic papillary carcinoma in which both a follow up histologic excision and an initial cytology fine needle aspirate sample for each patient were available for review. Several parameters were charted that are associated with higher stage/more aggressive tumors including extra-capsular extension, lymph node metastases, and size of the tumor equal or greater than 2 cm. Both histologic and cytologic samples were qualitatively reviewed for adequate cellularity. Tumor cellular areas from paraffin blocks and Romanowskystained direct smears were microdissected for DNA isolation. BRAF mutational analysis was performed by a PCR method utilizing pyrosequencing to detect the mutation of codon V600E. Results: In 32 cases, in which there was a histology and cytology sample, 27 cases (85%) were BRAF mutated and 5 cases (15%) were BRAF wildtype. Unfortunately, eight cases were not amplifiable, seven of these were cytology samples and 1 was a surgical sample. All eight samples had adequate cellularity by qualitative and quantitative analysis. The sensitivity of using fine needle aspirate material for BRAF testing was 0.684 and the specificity was 0.556 compared to using excisional material. After comparing cases with the mutation versus the wild-type, the presence of the BRAF mutation was not significantly associated with the presence of extrathyroidal extension, lymph node metastases, or the size of tumor equal or greater than 2 cm in the surgical excision case by Fisher’s exact test in both the biopsy and cytology results combined and in the FNA cytology cases alone.
S65 [1-5%], a definitive diagnosis is warranted as it dictates therapy and defines prognosis. FNAC has greatly improved management of ATC. The cytomorphologic features are specific for diagnosis and easily recognizable. Yet there are few large series in the literature on the role of FNAC. Our study focuses on FNAC as a pretherapy diagnostic modality replacing biopsy in ATC. Materials and Methods: Retrospective analysis was performed of 70 cases reported in 5 years in a tertiary cancer centre on FNAC as ATC or where ATC was included in the differential diagnosis. Cytomorphology was correlated with clinico-radiological features. The 9 diagnostic criteria were hypercellularity, loosely cohesive clusters and isolated cell pattern, large pleomorphic cells with raised N/C ratio, clumped chromatin and prominent nucleoli, abundant cytoplasm, easily identifiable mitosis, necrosis, multinucleated giant cells and inflammatory cells in background. On review, a diagnosis of ATC was retained in 60 cases. Results: Fifty patients presented with a large, rapidly enlarging, unilateral thyroid mass with obstructive symptoms. Only 10 patients presented with a diffuse fixed thyroid mass. All 9 diagnostic criteria were present in 20 [33%] cases. At least 6 criteria were present in 30 [50%] cases. Mitoses and necrosis were observed in 44 [73%] and 35 [58%] cases, respectively. Both features were seen in 25 [41%] cases. Leucophagocytosis a diagnostic clue e was observed in 12 [20%] cases. Predominant spindle cell type was noted in 9 [15%] cases; characterized by elongated hyperchromatic nuclei, insignificant nucleoli, few giant cells and inflammatory cells. Only 6 cases [10%] showed foci of differentiated thyroid carcinoma associated with ATC (3 cases each of papillary and follicular carcinoma). 2 cases of ATC showing papillary carcinoma foci were of spindle cell type; in contrast ATC cases with follicular carcinoma were of pleomorphic type. The diagnosis of ATC was confirmed on biopsy in 12 [20%] cases[4-spindle type, 8-pleomorphic type] where clinico-radiological features were not compatible with ATC or no differential diagnosis was offered on FNAC. In the remaining cases, FNAC diagnosis was compatible with the clinico-radiological diagnosis and treatment was planned accordingly. Conclusions: Definite diagnosis of ATC is reasonably attained on FNAC even though the differential diagnosis is quite wide. Poorly differentiated squamous carcinoma; the most common differential diagnosis; can be distinguished as these lack significant pleomorphism, multinucleated cells, prominent nucleoli, necrosis and inflammatory cells. Other differential diagnoses include medullary carcinoma and Hurthle cell carcinoma which can be differentiated by adhering to specific diagnostic criteria. Immunocytochemistry is necessary in a few cases to establish the correct diagnosis. FNAC is thus the method of choice for making a quick, cost effective, easy and reliable diagnosis of ATC. A confident diagnosis on FNAC obviates the need for biopsy/ surgery resulting in prompt planning of multimodal therapy. 112 Malignancy Rates in Bethesda Class III? Do Follicular Lesion of Undetermined Significance (FLUS) and Atypia of Undetermined Significance (AUS) Belong Together? Alexander Finkelstein, DO, MD, Fang Zhou, MD, Oliver Szeto, MD, Aylin Simsir, MD. Pathology, New York University School of Medicine, New York, New York Introduction: In 2007, a National Cancer Institute (NCI) sponsored consensus conference developed a unified “Bethesda Terminology System (BTS)” for reporting thyroid FNA diagnoses. The TBS places FLUS and AUS within the same category designated as Class III. Based on the TBS data, malignancy rate in this class ranges from 5 to 15% on surgical resection. However, studies published since 2007, including data from our institution, report markedly variable malignancy rates, ranging from 2 to 48%, suggesting that FLUS/AUS is not a homogeneous category. Morphologically FLUS is defined as predominance of a microfollicular pattern that does not otherwise fulfill the criteria for follicular neoplasm; whereas AUS refers more to the presence of nuclear atypia raising concern for papillary thyroid carcinoma (PTC). We sought to determine whether the malignancy rates in
S66
Abstracts
FLUS (microfollicular pattern) and AUS (nuclear atypia) are similar, and whether they should both be placed in Class III as currently recommended. Materials and Methods: The Pathology department database was queried to retrieve all thyroid FNA samples from January 1, 2010 to December 31, 2011. Surgical follow up diagnoses were reviewed for Class III (FLUS and AUS). Class III was divided into two groups; FLUS for cases with microfollicular pattern falling short of a definitive diagnosis of follicular neoplasm, and AUS for cases with nuclear atypia such as focal nuclear clearing, overlapping, enlargement and occasional grooves. The malignancy rates in each diagnostic group were calculated. Statistical analysis was performed using Pearson Chi-square analysis. Results: There were a total of 6701 specimens from 4647 patients. Of 239 FLUS/AUS cases, 95 (40%) had surgical follow up. The overall FLUS/ AUS rate was 3.6% with a FLUS/AUS to malignant ratio of 0.7. Of 95 FLUS/AUS cases with surgical follow up, 65 were FLUS and 30 AUS. Of the 65 FLUS cases, 23 (35.4%) had PTC on resection; 12 of the PTC cases were the follicular variant (FVPTC). 7 (10.8%) cases were follicular carcinoma, 16 (24.6%) were follicular adenoma, and 19 (29.2%) were nodular hyperplasia. Of 30 AUS cases, 24 (80%) were PTC, with 7 cases of FVPTC; 1 was (3.3%) a poorly differentiated follicular carcinoma, 2 (6.7%) were follicular adenoma, and 3 (10%) were nodular hyperplasia. The differences in the rates of PTC and follicular neoplasms were statistically significant (p value of 0.001) between the AUS and FLUS categories.
these, 9 cases were stage pT1N1, 6 pT1N2 and 53 pT1N0. In every specimen a representative tissue section containing both normal and tumor tissue was analyzed. The expression level for each antibody was evaluated as negative, mild, moderate and strong using a score system that takes into account the percentage of positive tumor cells as well as the intensity of staining. Results: Only a few scattered normal thyroid follicular cells showed mild expression of KiSS-1 and KISS1R. Strong immunoreactivity for KiSS-1 and KISS1R was detected in 90,3% and 80,1% cases with lymph node metastasis, respectively. Smaller PTCs confined within the thyroid gland showed lower levels of expression for both antibodies (42,1% and 24,6% respectively). Conclusions: Our data show an overexpression of KiSS-1 and KISS1R in papillary thyroid carcinomas compared with normal tissue. Our findings also indicate that there is a correlation between KiSS-1 and KISS1R expression and advanced stage of PTC. Taken together these first data suggest that despite the reported antimetastatic effect of KiSS-1 overexpression in various tumors, in the thyroid gland the transcription of KiSS-1 and/or KISS1R genes may play a role in modulating the biological behavior of thyroid cells, so that they acquire metastatic potential. Additional studies in larger series should help to further clarify this issue.
Follow-up Surgical Diagnoses in AUS and FLUS Cases
BRAF V600E on Fine Needle Aspiration: A Poor Test for Modifying Surgical Management in Classical Papillary Thyroid Carcinoma
Total Nodular Follicular Papillary Follicular Poorly Hypeplasia Adenoma Carcinoma Carcinoma Differentiated Carcinoma AUS 3 (10%) FLUS 19 (29%) Class III 22 (23%) Combined
2 (6.7%) 24 (80%) 16 (25%) 23 (35%) 18 (19%) 47 (49%)
0 7 (11%) 7 (7%)
1 (3.3%) 0 1 (1%)
30 65 95
Conclusions: The overall rate of malignancy in Class III in our laboratory is higher than that generally reported. There is a marked difference in the malignancy rate between FLUS and AUS confirming that Class III is a heterogeneous group. The incidence of PTC in AUS cases is significantly higher than in FLUS cases (80% versus 35%). On the other hand, follicular neoplasms are more frequent in cases of FLUS compared to AUS (36% versus 6.7%). Our findings suggest that nuclear atypia carries more significance than microfollicular pattern in prediction of malignancy in the indeterminate nodules (Class III). The overall high rate of malignancy in our study may be a result of multiple factors such as patient selection bias for surgical treatment based on other clinical findings (suspicious radiology, single nodule, etc) and the higher institutional threshold for placing cases in an indeterminate category. 113 Immunohistochemical Study of KiSS-1 and KISS1R Expression in Papillary Thyroid Carcinoma Ekaterini Politi, MD, PhD, Antonia Kapoula, MD, Helen Koutselini, MD, FIAC. Cytopathology Department, Aretaieio University Hospital, Athens, Greece Introduction: KiSS-1 and its G-protein coupled receptor (KISS1R) constitute a biological system involved in the regulation of GnRH release and have been reported to play a metastasis suppression role in various human malignancies. The expression profile of these two genes and its correlation with tumor progression has been slightly studied in thyroid tumors and especially papillary thyroid carcinoma (PTC). In spite of low mortality rates and overall favorable prognosis of PTCs, the worldwide incidence is high and increasing, especially among young adults. The aim of our study was to investigate the expression of KiSS-1 and KISS1R in PTCs and to correlate it with tumor stage and lymph node metastasis. Materials and Methods: Tumor samples from 69 patients with PTC were immunostained using antibodies against KiSS-1 and KISS1R. Among
114
Kelly Gilliland, DO, Hui-Jia Dong, PhD, Larry Fowler, MD. Pathology, University of Florida, Gainesville, Florida Introduction: Papillary thyroid carcinomas (PTC) represent the majority of malignant thyroid neoplasms. Recent studies have identified a mutation of the BRAF gene (BRAFV600E) in a large number of PTC. This mutation has been suggested to be associated with a more aggressive behavior and worse outcome in some studies. Many of these studies have included all variants including the follicular variant of papillary which is known to have a better prognosis and is BRAF wild-type. We proposed to determine BRAF expression in a limited population of only classical papillary carcinoma to elucidate the predictability of BRAF mutational presence with its’ associated prognosis. Additionally, we attempted a relatively new technique of using cytology fine needle aspirate specimens to determine the practicality of mutational analysis, as had been recommended by several publications promoting its use to determine a more aggressive surgical approach when the tumor is BRAF mutated. Materials and Methods: Our study reviewed cases of classic papillary carcinoma in which both a follow up histologic excision and an initial cytology fine needle aspirate sample for each patient were available for review. Several parameters were charted that are associated with higher stage/more aggressive tumors including extra-capsular extension, lymph node metastases, and size of the tumor equal or greater than 2 cm. Both histologic and cytologic samples were qualitatively reviewed for adequate cellularity. Tumor cellular areas from paraffin blocks and Romanowskystained direct smears were microdissected for DNA isolation. BRAF mutational analysis was performed by a PCR method utilizing pyrosequencing to detect the mutation of codon V600E. Results: In 32 cases, in which there was a histology and cytology sample, 27 cases (85%) were BRAF mutated and 5 cases (15%) were BRAF wildtype. Unfortunately, eight cases were not amplifiable, seven of these were cytology samples and 1 was a surgical sample. All eight samples had adequate cellularity by qualitative and quantitative analysis. The sensitivity of using fine needle aspirate material for BRAF testing was 0.684 and the specificity was 0.556 compared to using excisional material. After comparing cases with the mutation versus the wild-type, the presence of the BRAF mutation was not significantly associated with the presence of extrathyroidal extension, lymph node metastases, or the size of tumor equal or greater than 2 cm in the surgical excision case by Fisher’s exact test in both the biopsy and cytology results combined and in the FNA cytology cases alone.