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Atypical Follicular Adenoma Of Thyroid: Cytomorphologic Features on Fine Needle Aspiration Biopsy And Histologic Correlation
S48
Abstracts
Materials and Methods: Forty-two cases of thyroid FNAs with original diagnoses of benign (nZ11), AUS (nZ17) and SFN (nZ14), with architectural atypia were randomly selected by a cytopathologist from the archives after review. All slides from each case (including the Papanicolaou stained smears and ThinPrep) were distributed for evaluation to other study participants (2 cytopathologists, 1 cytopathology fellow), blinded to the original diagnoses. The cytologic features were recorded and the kappa statistics were calculated. Results: The overall interobserver agreement for diagnoses by four different observers (including the original cytopathologist) was fair (kappa Z 0.25). Twenty three cases revealed moderate agreement ( 3 observers with same diagnosis, kappa Z 0.52). The cytologic features of the latter as recorded by the 3 study participants are summarized below (Table 1). Conclusions: Our study indicates that the use of objective parameters i.e. qualifying the percentage of cells in microfollicular pattern and/or syncytial groups in relation to the cellularity, the amount of colloid and the presence or absence of nuclear atypia can improve the interobserver agreement in assessment of thyroid FNAs. Table 1 Majority diagnosis
% cells in microfollicular pattern/syncytial groups
Benign
5
5-70%
AUS
4
40-100%
AUS
4
30-90%
SFN
10
60-100%
Table 1 Cytologic features
Features of PTC (NG, NC, INCI)
Colloid
Microfollicles
Oncocytes
Number of cases
3
Absent-2 Scant- 2 Abundant-2
2
2
108
Cytologic Features - Cases with Most Interobserver Agreement No. of cases
classic and follicular variants. Presence or absence of colloid is not helpful in characterizing the lesion. Lobectomy or subtotal thyroidectomy are the recommended surgical treatments. N2-RAS and TP53 mutations in AFA suggest premalignant nature, representing precursor lesions of follicular carcinoma. AFA is reported to have a benign course with excellent long term prognosis, but close clinical follow up with clinical exam, ultrasound and serum thyroglobulin are recommended.
Cellularity
Amount of colloid
Nuclear Atypia
The Bethesda Thyroid Fine-Needle Aspiration Classification System for Reporting Thyroid Cytopathology: Analysis in an Academic Institution
Low to marked Scant to moderate Scant to moderate Moderate to marked
Moderate to abundant Scant
Absent
Maureen Cioffi-Lavina, DO, German Campuzano-Zuluaga, MD, Parvin Ganjei-Azar, MD, Claudia P. Rojas, MD, Merce Jorda, MD, Saleem Umar, MD, Carmen Gomez-Fernandez, MD, Monica T. Garcia-Butrago, MD University of Miami, Miami, Florida
Scant to moderate Scant
Present/ Absent Present Present/ Absent
107 Atypical Follicular Adenoma Of Thyroid: Cytomorphologic Features on Fine Needle Aspiration Biopsy And Histologic Correlation Vaidehi Avadhani, MD1, Zheng Ma, MD1, Jean-Marc Cohen, MD2, Manju Harshan, MD2 1 St. Luke's Roosevelt Hospital, New York, New York; 2Beth Israel Medical Center, New York, New York Introduction: Atypical follicular adenoma (AFA) is a rare variant of follicular adenoma (FA) of thyroid. It is characterized by thick capsule, increased cellularity, hypercellularity along the tumor-capsule interface, increased mitotic activity including atypical forms, necrosis, prominent nucleoli and infarction. Capsular and vascular invasion are not seen. Encapsulated follicular tumors showing equivocal cytomorphologic features of Papillary thyroid carcinoma (PTC) without invasion is also termed AFA. The aim of the study is to characterize the cytologic features of AFA in fine needle aspiration biopsies (FNAB) and correlate with histologic features. Materials and Methods: Retrospective search in the pathology system of our institution was done for histologic diagnosis of AFA from 01/2007 to 10/2012. Six cases were identified which had FNAB of the nodule before surgery. Three were males and 3 females. Ages ranged from 24 to 67 yrs. Four were solitary nodules and 2 part of multinodular goiter. Size of the nodules ranged from 1.2 to 5.5 cm. FNAB of 5 nodules were done with palpation and 1 with ultrasound guidance. On FNAB, 3 cases were reported as suspicious for PTC and 3 as follicular neoplasms. Four patients underwent subtotal thyroidectomy and 2 total thyroidectomy. Results: Findings of FNAB are shown in the table. On review of the histology, all 6 cases showed thick capsule, increased cellularity and equivocal features of PTC like nuclear grooves (NG), nuclear clearing (NC) and intracytoplasmic inclusions (INCI). Extent of these changes were focal and not significant enough to call PTC. Capsular and vascular invasion were not seen. No recurrences or metastasis were reported in any of these patients to date. Conclusions: AFA on FNAB can present as follicular neoplasm, follicular neoplasm with oncocytic features or with features suspicious for PTC,
Introduction: The Bethesda Classification System (TBS) for reporting fineneedle aspiration (FNA) of thyroid facilitates the management of thyroid disease based on the risk of malignancy. A four-category scheme, that combines Bethesda categories (BC) IV, V and VI, would align with current management. We analyzed the diagnostic performance of using a fourcategory system versus the TBS in our institution. Materials and Methods: We evaluated the pathology reports of thyroid FNAs available in our system between 2003 and 2011 and included cases that had thyroidectomy with tissue diagnosis. We calculated the sensitivity and specificity of the combined BC V and VI (combined risk category [CRC] 1) or BC IV, V and VI (CRC2) groups versus the benign BC II, to detect malignancy in thyroidectomies. Differences in diagnostic performance between the two CRCs were obtained and 95% confidence intervals (CI) calculated. Results: Ninety-two samples were available for the analysis. Table 1 shows the distribution of cases by BC and histologic diagnosis. The sensitivity and specificity for detection of malignancy by the CRC1 combination was 86.2% (nZ29/ 73) and 93.2% (nZ44/73) respectively. The sensitivity and specificity for detection of malignancy by the CRC2 combination was 89.5% (nZ38/92) and 75.9% (nZ54/92) respectively. There was no significant difference in the sensitivity for detection of malignancy between the CRC1 and CRC2 combinations (3.3%, 95% CI -12.6% - 19.2%). There was a significant decrease in specificity from the CRC1 to the CRC2 combination (-17.3%, 95% CI -3.6% - -30.9%). Conclusions: Results demonstrate that CRC1 and CRC2 combinations have a comparable sensitivity. Although the CRC2 combination shows an increase in false positive cases; patients with BC IV will benefit from surgery, since 47.4% will have a carcinoma on tissue diagnosis. Using a four-category system, with CRC2 harboring a higher probability for malignancy requiring surgery, is in alignment with current treatment strategies. Table 1
Distribution of final tissue diagnosis by BC.
Bethesda category
FTS: Benign Count (%)
FTS: Malignant Count (%)
Total Z 171
Benign Indeterminate Follicular neoplasm Suspicious for malignancy Malignant
41 49 10 2 1
4 30 9 8 17
45 79 19 10 18
FTD: final tissue diagnosis.
(91.1%) (62.0%) (52.6%) (20.0%) (5.6%)
(8.9%) (38.0%) (47.4%) (80.0) (94.4%)
Abstracts
Materials and Methods: Forty-two cases of thyroid FNAs with original diagnoses of benign (nZ11), AUS (nZ17) and SFN (nZ14), with architectural atypia were randomly selected by a cytopathologist from the archives after review. All slides from each case (including the Papanicolaou stained smears and ThinPrep) were distributed for evaluation to other study participants (2 cytopathologists, 1 cytopathology fellow), blinded to the original diagnoses. The cytologic features were recorded and the kappa statistics were calculated. Results: The overall interobserver agreement for diagnoses by four different observers (including the original cytopathologist) was fair (kappa Z 0.25). Twenty three cases revealed moderate agreement ( 3 observers with same diagnosis, kappa Z 0.52). The cytologic features of the latter as recorded by the 3 study participants are summarized below (Table 1). Conclusions: Our study indicates that the use of objective parameters i.e. qualifying the percentage of cells in microfollicular pattern and/or syncytial groups in relation to the cellularity, the amount of colloid and the presence or absence of nuclear atypia can improve the interobserver agreement in assessment of thyroid FNAs. Table 1 Majority diagnosis
% cells in microfollicular pattern/syncytial groups
Benign
5
5-70%
AUS
4
40-100%
AUS
4
30-90%
SFN
10
60-100%
Table 1 Cytologic features
Features of PTC (NG, NC, INCI)
Colloid
Microfollicles
Oncocytes
Number of cases
3
Absent-2 Scant- 2 Abundant-2
2
2
108
Cytologic Features - Cases with Most Interobserver Agreement No. of cases
classic and follicular variants. Presence or absence of colloid is not helpful in characterizing the lesion. Lobectomy or subtotal thyroidectomy are the recommended surgical treatments. N2-RAS and TP53 mutations in AFA suggest premalignant nature, representing precursor lesions of follicular carcinoma. AFA is reported to have a benign course with excellent long term prognosis, but close clinical follow up with clinical exam, ultrasound and serum thyroglobulin are recommended.
Cellularity
Amount of colloid
Nuclear Atypia
The Bethesda Thyroid Fine-Needle Aspiration Classification System for Reporting Thyroid Cytopathology: Analysis in an Academic Institution
Low to marked Scant to moderate Scant to moderate Moderate to marked
Moderate to abundant Scant
Absent
Maureen Cioffi-Lavina, DO, German Campuzano-Zuluaga, MD, Parvin Ganjei-Azar, MD, Claudia P. Rojas, MD, Merce Jorda, MD, Saleem Umar, MD, Carmen Gomez-Fernandez, MD, Monica T. Garcia-Butrago, MD University of Miami, Miami, Florida
Scant to moderate Scant
Present/ Absent Present Present/ Absent
107 Atypical Follicular Adenoma Of Thyroid: Cytomorphologic Features on Fine Needle Aspiration Biopsy And Histologic Correlation Vaidehi Avadhani, MD1, Zheng Ma, MD1, Jean-Marc Cohen, MD2, Manju Harshan, MD2 1 St. Luke's Roosevelt Hospital, New York, New York; 2Beth Israel Medical Center, New York, New York Introduction: Atypical follicular adenoma (AFA) is a rare variant of follicular adenoma (FA) of thyroid. It is characterized by thick capsule, increased cellularity, hypercellularity along the tumor-capsule interface, increased mitotic activity including atypical forms, necrosis, prominent nucleoli and infarction. Capsular and vascular invasion are not seen. Encapsulated follicular tumors showing equivocal cytomorphologic features of Papillary thyroid carcinoma (PTC) without invasion is also termed AFA. The aim of the study is to characterize the cytologic features of AFA in fine needle aspiration biopsies (FNAB) and correlate with histologic features. Materials and Methods: Retrospective search in the pathology system of our institution was done for histologic diagnosis of AFA from 01/2007 to 10/2012. Six cases were identified which had FNAB of the nodule before surgery. Three were males and 3 females. Ages ranged from 24 to 67 yrs. Four were solitary nodules and 2 part of multinodular goiter. Size of the nodules ranged from 1.2 to 5.5 cm. FNAB of 5 nodules were done with palpation and 1 with ultrasound guidance. On FNAB, 3 cases were reported as suspicious for PTC and 3 as follicular neoplasms. Four patients underwent subtotal thyroidectomy and 2 total thyroidectomy. Results: Findings of FNAB are shown in the table. On review of the histology, all 6 cases showed thick capsule, increased cellularity and equivocal features of PTC like nuclear grooves (NG), nuclear clearing (NC) and intracytoplasmic inclusions (INCI). Extent of these changes were focal and not significant enough to call PTC. Capsular and vascular invasion were not seen. No recurrences or metastasis were reported in any of these patients to date. Conclusions: AFA on FNAB can present as follicular neoplasm, follicular neoplasm with oncocytic features or with features suspicious for PTC,
Introduction: The Bethesda Classification System (TBS) for reporting fineneedle aspiration (FNA) of thyroid facilitates the management of thyroid disease based on the risk of malignancy. A four-category scheme, that combines Bethesda categories (BC) IV, V and VI, would align with current management. We analyzed the diagnostic performance of using a fourcategory system versus the TBS in our institution. Materials and Methods: We evaluated the pathology reports of thyroid FNAs available in our system between 2003 and 2011 and included cases that had thyroidectomy with tissue diagnosis. We calculated the sensitivity and specificity of the combined BC V and VI (combined risk category [CRC] 1) or BC IV, V and VI (CRC2) groups versus the benign BC II, to detect malignancy in thyroidectomies. Differences in diagnostic performance between the two CRCs were obtained and 95% confidence intervals (CI) calculated. Results: Ninety-two samples were available for the analysis. Table 1 shows the distribution of cases by BC and histologic diagnosis. The sensitivity and specificity for detection of malignancy by the CRC1 combination was 86.2% (nZ29/ 73) and 93.2% (nZ44/73) respectively. The sensitivity and specificity for detection of malignancy by the CRC2 combination was 89.5% (nZ38/92) and 75.9% (nZ54/92) respectively. There was no significant difference in the sensitivity for detection of malignancy between the CRC1 and CRC2 combinations (3.3%, 95% CI -12.6% - 19.2%). There was a significant decrease in specificity from the CRC1 to the CRC2 combination (-17.3%, 95% CI -3.6% - -30.9%). Conclusions: Results demonstrate that CRC1 and CRC2 combinations have a comparable sensitivity. Although the CRC2 combination shows an increase in false positive cases; patients with BC IV will benefit from surgery, since 47.4% will have a carcinoma on tissue diagnosis. Using a four-category system, with CRC2 harboring a higher probability for malignancy requiring surgery, is in alignment with current treatment strategies. Table 1
Distribution of final tissue diagnosis by BC.
Bethesda category
FTS: Benign Count (%)
FTS: Malignant Count (%)
Total Z 171
Benign Indeterminate Follicular neoplasm Suspicious for malignancy Malignant
41 49 10 2 1
4 30 9 8 17
45 79 19 10 18
FTD: final tissue diagnosis.
(91.1%) (62.0%) (52.6%) (20.0%) (5.6%)
(8.9%) (38.0%) (47.4%) (80.0) (94.4%)