The spectrum of thyroid lesions on fine needle aspiration cytology

Background: Fine Needle Aspiration Cytology (FNAC) of thyroid gland is the most common preoperative investigation for diagnosis of thyroid lesions. Though various tests like thyroid profile, ultrasonography and radionuclide scan are available, they are used as adjuvant diagnostic modalities. FNAC is simple, easy to perform, non-invasive and cost-effective procedure. Primary aim is to study the spectrum of various thyroid lesions on FNAC. Also, the study is aimed to categorise the thyroid lesions according to the Bethesda system for Reporting Thyroid Cytopathology (2017).Methods: This is a retrospective observational study carried out in the pathology department at tertiary care academic institute for a period of three years. FNAC was done in a patient with thyroid swelling by non-aspiration technique. Slides were prepared, fixed in 95% ethyl alcohol and processed with routine stains.Results: Out of 210 cases, 150 cases (71.42%) were benign lesions, 15 cases (7.14%) were Follicular neoplasm/Suspicious for follicular neoplasm, 14(6.66%) cases were reported as Atypia of undetermined significance, 13 cases (6.19%) were Unsatisfactory/Nondiagnostic, 11 cases (5.2%) were malignant and 7 cases (3.3%) were suspicious for malignancy.Conclusions: FNAC is the most effective tool for the diagnosis of thyroid lesions. The Bethesda system is used to categorise the thyroid lesions and helps in better communication between clinicians and pathologists for the best surgical and medical management. The number of benign cases were higher and the number of cases in the category of suspicious for malignancy were lower with female preponderance.

Differential Diagnosis of Thyroid Follicular Neoplasm from Nodular Hyperplasia by Shear Wave Elastography

OBJECTIVE: More than 50% of diagnostic surgery in cytologically indeterminate thyroid nodules revealed benign nodules of which nodular hyperplasia (NH) accounted for about half. Preoperative exclusion of NH may decrease diagnostic surgery. We aimed to study the diagnostic performance of shear wave elastography (SWE) to differentiate follicular neoplasm (FN) from NH in follicular lesions of thyroid nodules. METHODS: We analyzed the data from 61 patients who underwent SWE before ultrasound-guided core-needle biopsy (CNB) from August 2016 to May 2018 and CNB results were FN (n=19) and NH (n=42). We analyzed the magnitude of elasticity index (EI) and patterns of high EI area (EI >36 kPa). The patterns of high EI area was classified as marginal pattern (high EI areas are restricted in the outer 1/3 of the nodule) and traversing pattern (high EI areas approaching further to the center of the nodule within inner 2/3 of the nodule). RESULTS: The E(Max), E(Mean), E(SD), and percent of high EI area were significantly lower in FN than NH (P<0.001). The diagnostic performance to predict FN showed sensitivity, specificity, and accuracy of 95%, 90%, and 92% by E(Max) <42.1 kPa, and of 95%, 79%, and 84% by E(Mean) <23.5 kPa, and of 89%, 93%, and 92% by marginal pattern of high EI area, respectively. CONCLUSION: Novel diagnostic criteria of E(Max) less than 42.1 kPa and marginal pattern of high EI area on SWE can predict FN with high diagnostic accuracy, waiving diagnostic surgery of NH in indeterminate cytology.

Cytological Features That Differentiate Follicular Neoplasm from Mimicking Lesions

BACKGROUND: It is difficult to correctly diagnose follicular neoplasms (FNs) on fine-needle aspiration cytology (FNAC) because it shares many cytological features with other mimicking lesions. The aim of this study was to identify the cytological features that differentiate FNs from mimicking lesions. METHODS: We included the cytological slides from 116 cases of thyroid FN diagnosed on FNAC, and included their subsequent histological diagnoses. We evaluated the cytological architectural pattern and nuclear features of the lesions according to their histological groups. RESULTS: The final histological diagnoses of the 116 cases varied, and included 51 FNs (44%), 47 papillary thyroid carcinomas (40%) including follicular variant, and seventeen cellular nodular hyperplasias (15%). Regardless of the final histological diagnosis, microfollicular pattern was observed in most cases. On the other hand, trabecular pattern was identified in 34% of FNs, but not in any other lesions. Additionally, elongated nuclei and ground glass chromatin were found in only some papillary thyroid carcinomas. CONCLUSIONS: This study shows that the trabecular pattern is a representative cytological feature of FNs that can be used to distinguish FNs from mimicking lesions. In addition, nuclear shape and chromatin pattern can be used to further confirm the diagnosis of FNs from mimicking lesions through FNAC.

Diferencias y controversias entre el reporte de patología y la interpretación clínica en patología tiroidea. I parte: Factores pronósticos / Thyroid pathology: differences and controversies between the pathology report and clinical interpretation. Part I: prognostic factors

Resumen El cáncer de la glándula tiroides es una neoplasia cuya detección, diagnóstico y tratamiento se realiza de manera interdisciplinaria, por lo tanto el diagnóstico definitivo histopatológico debe ser completo y claro; de modo que pueda ser interpretado de la misma manera por parte del grupo médico tratante. De manera frecuente, los médicos no patólogos que reciben el reporte de un estudio histopatológico de tiroides se enfrentan con dificultades al momento de interpretar el reporte histopatológico y，por lo tanto, en definir la posterior conducta médica. El objetivo de este primer artículo es revisar de manera breve algunos de los diferentes temas que más generan dudas en la interpretación del reporte histopatológico y de las técnicas diagnósticas usadas en patología por parte de los médicos tratantes que tienen un impacto en las decisiones clínicas originadas a partir de la clasificación, estadificación, pronóstico y seguimiento de la enfermedad.

Abstract Cancer of the thyroid gland is a neoplasia for which its detection, diagnosis and treatment is interdisciplinary. For this reason, the definitive diagnosis by histopathology should be complete and clear so that it can be interpreted in the same way by the treating medical group. Non-pathology physicians who receive the report of a histopathological study of the thyroid often have difficulties when interpreting the report and therefore in defining the subsequent medical behaviour. The objective of this first article is to review briefly some of the different subjects that generate most doubts in the interpretation of the histopathology report, and the diagnostic techniques used in pathology by the attending physicians that have an impact on clinical decisions arising from the classification, staging, prognosis, and follow-up of the disease.

Hits and misses in diagnosis of thyroid lesions Cytohistological correlation

Background: Fine needle aspiration of thyroid neoplasm is cost effective procedure to differentiate between benign and malignant lesions in most of the cases. Aim: To evaluate the accuracy of FNAC in diagnosis of different thyroid lesions, particularly differentiation of malignant and non malignant lesions. Materials and methods: Study comprised of 220 cases of thyroid FNAC’s which were followed by excision biopsy. Their FNAC’s diagnosis was compared with histopathological diagnosis. Results: Among 220 cases of FNAC’s 151 was diagnosed as benign (68.63%), 58 cases as malignant (26.36%) and 11 case as follicular neoplasms (5.0%). Colloid goitre represented the majority of benign cases while papillary carcinoma was the most frequent malignant lesion. Cytological findings were compared with their corresponding histopathological findings. Conclusion: Benign and malignant thyroid lesions can be differentiate accurately by FNAC however certain pitfalls should be kept in mind.

Supplementary Role of Ultrasonography and Intraoperative Frozen Section Analysis in Diagnosis of Follicular Variant of Papillary Thyroid Carcinomas / 대한내분비외과학회지

PURPOSE: The follicular variant of papillary thyroid carcinoma (FVPTC) is the most common variant of papillary thyroid carcinoma (PTC). Preoperative diagnosis of FVPTC is often confused with cPTC, follicular neoplasm (FN), and benign follicular lesion because of the paucity of nuclear changes of PTC and overlapping features with benign and other neoplastic follicular lesions. The aim of this study is to elucidate whether ultrasonography and/or intraoperative frozen section analysis (FSA) have a supplementary role in the diagnosis of FVPTC. METHODS: Fifty-five patients diagnosed with histologically confirmed FVPTC from January 2007 to December 2013 were identified. All patients had undergone either lobectomy with/without completion thyroidectomy or total thyroidectomy. Medical records, final histological reports and sonographic (US) findings were reviewed. All sonographic images, 53 fine needle aspiration cytology (FNAC) slides, and FSA slides for 24 cases were available for reexamination. RESULTS: Three histologic types of FVPTC were identified: encapsulated (n=39); infiltrative (n=15); and diffuse (n=1). There were two distinct sonographic patterns: FN-type (n=28) and PTC-type (n=27). The encapsulated type is more common in the FN-like pattern, compared to the PTC-like one (85.7% vs. 55.6%, P=0.009). Among the 24 cases in which sonographic images and FNAC and FSA slides were available for review, six cases (25%) were diagnosed as either FN in FNAC and suspicious PTC(R/O PTC)/PTC in FSA or R/O PTC/PTC in FNAC and FN in FSA. Among those 24 cases described above, 13 cases (54.2%) were diagnosed as either FN-type in US and R/O PTC/PTC in FNAC/FSA or PTC-type in US and FN in FNAC/FSA. CONCLUSION: It is difficult to make a correct diagnosis of FVPTC before definitive treatment even with US, FNAC and FSA. However the possibility of FVPTC must be considered, especially when diagnoses in US, FNAC and FSA are different and include R/O PTC/PTC and FN in the same case.

The Diagnostic Usefulness of HMGA2, Survivin, CEACAM6, and SFN/14-3-3 delta in Follicular Thyroid Carcinoma

BACKGROUND: Follicular thyroid carcinoma (FTC) is the second most common thyroid malignancy and its differential diagnosis includes follicular adenoma (FA) and adenomatous goiter (AG). Several ancillary markers have been suggested to aid in the diagnosis of FTC, but the successful use of these methods still needs to be validated. METHODS: In the present study, we verified the immunoexpression of HMGA2, CEACAM6, survivin, and SFN/14-3-3 delta in lesions including 41 AGs, 72 FAs, and 79 FTCs. We evaluated their diagnostic usefulness, combined with galectin 3, Hector Battifora mesothelial 1 (HBME1), cytokeratin 19, and cyclin D1, in diagnosing FTC. RESULTS: The expressions of HBME1 (65.8%) and HMGA2 (55.7%) were significantly higher in FTCs than in FAs and AGs (p<.001 and p=.005, respectively). HBME1 was the only marker that was more frequently expressed in FTCs than in FAs (p=.021) and it was more frequently expressed in follicular neoplasms than in AGs (p<.001). Among the novel markers, the combination of HMGA2 and HBME1 showed the highest sensitivity (72.2%) and specificity (76.1%) for diagnosing FTC. CEACAM6, survivin, and SFN/14-3-3 delta were barely expressed in most cases. CONCLUSIONS: Our present results show that only HMGA2 can be beneficial in differentiating FTC using the novel markers.

Diagnostic Value of Preoperative Serum Thyroglobulin Measurement for the Diagnosis of Malignancy in Follicular or Hurthle Cell Neoplasms of the Thyroid Gland / 고신대학교의과대학학술지

OBJECTIVES: The aim of this retrospective study was whether serum Tg predicts malignancy in follicular or Hurthle-cell neoplasms on fine needle aspiration. METHODS: A chart review of 111 patients (90 females, 21 males; mean age 46.8 +/- 11.9 years) with follicular or Hurthle-cell neoplasms on fine needle aspiration, who were surgically treated between Sep. 2001 and Sep. 2011, was performed. Predictive factors for malignancy were identified by the chi-squared test and multivariate logistic regression. RESULTS: There were no differences between 41 malignant and 70 benign lesions in serum Tg or any of the normalized indexes. Receiver-operator characteristic analysis revealed no cut-off value. Lesions with serum Tg levels greater than 500 g/L had no significant difference. And also there were no independent predictors of malignancy by multivariate logistic regression. CONCLUSIONS: In this study, the author found that serum Tg has poor accuracy for predicting malignancy in follicular or Hurthle cell neoplasms on fine needle aspiration.

Thyroid nodules with Bethesda System IV Cytology: Can Ultrasonography Differentiate Malignancy from Benign?

PURPOSE: The purpose of this study is to identify clinical and imaging parameters that can be used in differentiation of benign versus malignancy of preoperative FNA diagnosis of Bethesda system IV nodules. MATERIALS AND METHODS: We analyzed clinical, ultrasonographic, and CT findings of 28 thyroid nodules with Bethesda system IV cytology on FNA, which were proven as follicular or Hurthle cell neoplasms on surgical pathology. RESULTS: No statistically significant differences according to age, sex, and ultrasonographic parameters, including echogenicity, margin, calcification, shape, cystic component, and degree of vascularity and enhancement on CT were observed between benign and malignant follicular neoplasms. Only the lesion size was significantly different (p<0.05). CONCLUSION: The size of follicular neoplasm is predictive of malignancy. If a thyroid nodule with the Bethesda IV cytology is larger than 24.5 mm, there will be a greater probability of malignancy.

Definition and Prognostic Factor of Minimally Invasive Follicular Thyroid Carcinoma / 대한내분비외과학회지

Minimally invasive follicular thyroid carcinoma (MIFTC) is a subtype of follicular thyroid carcinoma. The definition of MIFTC is somewhat confusing; as a result, diagnosis of MIFTC is difficult. MIFTC is known to have an excellent prognosis. Thus, no further treatment is usually required after diagnostic lobectomy. However, some patients with MIFTC experience distant metastasis after initial lobectomy. In this review, we will discuss the definition of MIFTC and risk factors of distant metastasis after initial lobectomy.

Fine Needle Aspiration Cytology of Thyroid Follicular Neoplasm: Cytohistologic Correlation and Accuracy

BACKGROUND: This study evaluated the accuracy of fine needle aspiration cytology (FNAC) in cases of follicular neoplasm (FN) on the basis of histologic diagnosis, and reviewed the cytologic findings of FN according to the FNAC. METHODS: Among the 66 cases diagnosed with thyroid FN by FNAC during the 7-year period from 2003 to 2009, 36 cases that had undergone thyroid surgery were available for review. Cytologic diagnosis was compared with the histologic diagnosis of each case. RESULTS: Among the 36 cases with a cytologic diagnosis of thyroid FN, histologic diagnosis was as follows: 20 follicular adenomas (55.6%), 3 Hurthle cell adenomas (8.3%), 2 follicular carcinomas (5.6%), 8 nodular goiters (22.2%), 2 papillary carcinomas (5.6%), and 1 Hashimoto's thyroiditis (2.8%), resulting in a diagnostic accuracy of FNAC for thyroid FN of 69.5%. CONCLUSIONS: This study shows that FNAC for thyroid FN is a useful primary screening method because when FN is diagnosed by FNAC, the rate of FN histologic diagnosis is relatively high, however, adequate sampling and experience is a prerequisite for this procedure.

Hallazgos anatomopatológicos definitivos en pacientes tiroidectomizados con diagnóstico preoperatorio de neoplasia folicular / Definitive anatomopathological findings in thyroidectomized patients with preoperative diagnosis of follicular neoplasm

Background: The finding of follicular neoplasm, using a FNAP, is an indication for partial or total thyroidectomy, to obtain the definitive malignant or benign histology. Frequently, it is possible to identify significant additional histological diagnosis. Aim: To obtain the definitive histological findings in patients with follicular neoplasm by FNAP. Patients and Method: Transversal analysis of 133 patients that underwent to total thyroidectomy between 2003 and 2009, that filled de requirements for adequate histological assessment. Results: In 33.1 percent of the treated patients the final diagnosis was indeed a follicular neoplasm (adenoma in 26.3 percent and cancer in 6.8 percent). In the 51.9 percent the finding was follicular colloidal hyperplasia and other thyroid cancer in 8.3 percent. The total malignant prevalence in the whole gland was 29.3 percent. Conclusions: The thyroidec-tomy is the treatment of choice and the final diagnostic procedure for these patients. The histological findings of cancer different from follicular not only in the punctioned nodule are a secondary and an additional argument for reinforcing the surgical indication.

Introducción: El hallazgo de una neoplasia folicular por PAAF, obliga a realizar una tiroidectomía parcial o total, para definir la naturaleza maligna o benigna definitiva de la lesión tiroidea. Junto a este diagnóstico preoperatorio se identifican finalmente con alta frecuencia lesiones histológicas adicionales. Objetivo: Conocer y describir los hallazgos anatomopatológicos definitivos que se encuentran en tiroidectomías por neoplasias foliculares diagnosticadas por PAAF. Materiales y Métodos: Revisión transversal de las biopsias definitivas de 133 pacientes sometidos a tiroidectomía total entre 2003 y 2009, que cumplieron los requisitos establecidos para evaluar la histología definitiva del nódulo puncionado y de la glándula tiroides completa. Resultados: En el 33,1 por ciento de los pacientes el diagnóstico definitivo del nódulo puncionado fue efectivamente una neoplasia folicular (adenoma en el 26,3 por ciento y cáncer en el 6,8 por ciento). El 51,9 por ciento correspondió a hiperplasia folicular y el 8,3 por ciento otro cáncer. La prevalencia de malignidad final en la glándula completa fue de un 29,3 por ciento. Conclusiones: Siendo la indicación de tiroidectomía en estos pacientes un tratamiento y procedimiento diagnóstico aceptado y necesario, se concluye que la alta prevalencia de lesiones malignas (29,3 por ciento) tanto en el nódulo puncionado como, adicionalmente, en el resto de la glándula, reforzaría la necesidad de este tratamiento quirúrgico.

Predictive Factors of Malignancy in Thyroid Nodules Diagnosed as Follicular Neoplasm or Hürthle Cell Neoplasm on FNA / 대한내분비외과학회지

PURPOSE: The rate of malignancy in the follicular neoplasm (FN) or Hürthle cell neoplasm (HCN) of the thyroid gland is estimated as approximately 20~30%. Fine-needle aspiration biopsy (FNAB) and frozen section examination are restricted in differentiating between benign and malignant. The aims of this study are to compare the differences of clinicopathologic features and to determine the risk factors for malignancy in patients with FN or HCN. METHODS: A retrospective study was conducted of patients with FN or HCN who were diagnosed by FNAB, and underwent surgery at our institution between Jan. 2005 to Jun. 2010. We analyzed the risk factors for malignancy and the differences of clinicopathologic features in patients with FN or HCN. RESULTS: A total of 290 patients were enrolledin this study; 160 (55.2%) patients underwent thyroidectomy, 97 (60.6%) patients had FN, and 63 (39.4%) had HCN. Forty one (25.6%) patients were diagnosed as malignancy of these, 22 (22.7%) patients were FN and 19 (30.2%) were HCN (P=0.29). Two (2.1%) patients with FN and 10 (15.9%) with HCN (P=0.002) comcomitant papillary thyroid carcinoma were indentified by FNAB. Classification of nodules according to ultrasonographic findings in both neoplasms (P<0.05) and galectin-3 in FN (P<0.05) were predictive factors for malignancy. In addition, galectin-3 was a predictive factor for malignancy in indeterminate nodules on ultrasonography (USG) (P=0.028). CONCLUSION: Classification of nodules according to ultrasonographic findings and galectin-3 expression is helpful in predicting carcinoma of patients with FN or HCN.

Problems in Diagnosis and Management of Follicular Neoplasm / 대한갑상선학회지

Thyroid follicular adenoma and hyperplastic adenomatoid nodule may show overlapping cytologic pattern with thyroid follicular carcinoma and follicular variant of thyroid papillary carcinoma. Fine-needle aspiration cytology (FNAC) has limited role in differential diagnosis of those lesions showing high cellularity and absence of colloid. Those lesions are conventionally termed 'follicular neoplasm'. As diagnostic hallmarks of follicular carcinoma (vascular- and capsular invasion) cannot be detected by cytology, verification by histology after surgery is mandatory. However, only 20% of patients with thyroid nodules diagnosed cytologically as 'follicular neoplasm' are finally diagnosed as carcinoma after surgery. Therefore, there have been many trials to differentiate follicular adenoma (FA) from follicular carcinoma (FTC) in preoperative setting. Among those trials are 1) cell morphometry analysis by computer graphics, analysis of telomerase expression level, quantitation of specific protein markers, or intensive cytological analysis using FNAC specimens, 2) ultrasonographic evaluation, dynamic MRI, or MR spectroscopy for thyroid nodules and 3) gene expression profile analysis for thyroid nodules by microarray technique, all showing limited success or limitations hampering clinical application. Similarly, intra-operative frozen section analysis of thyroid nodule had been known to be of no diagnostic utility in a prospective, randomized trial. Current management strategy for 'follicular neoplasm' is initial surgery for diagnostic purpose to get pathologic diagnosis. If the nodule is diagnosed finally as FTC, completion thyroidectomy with or without radioactive iodine therapy is recommended in most cases. Minimally invasive FTC (without vascular invasion) is known to have excellent prognosis in most cases, so traditionally those patients had undergone unilateral operation without completion thyroidectomy. But, there had been reported cases showing distant metastasis and/or recurrence in patients with 'minimally invasive FTC'. One of problems in diagnosis of 'minimally invasive FTC' is lack of international standardization for pathologic diagnosis. Optimal surgical extent for cases with FTC is not known yet. It might have been due to lack of risk stratification of patients which is unique to FTC (not well differentiated thyroid cancer as a whole), lack of biomarker predicting prognosis of FTC, and lack of controlled trial for management of patients with FTC. In near future, application of molecular diagnostic markers is expected to improve our management strategy for thyroid nodules diagnosed as 'follicular neoplasm', if molecular pathogenesis of FA and of FTC are comprehensively understood.

Can Review of Sonographic Findings Spare Diagnostic Thyroidectomy in Patients with Thyroid Nodules Suspicious of Follicular Neoplasm Cytologically?

PURPOSE: Follicular neoplasms (FNs) such as follicular adenoma and carcinoma (FTC), nodular hyperplasia (NH) and follicular variant of papillary carcinoma (FVPC) share cytological features. In the present study, we investigate whether review of sonographic findings in patients with thyroid nodules suspicious of FN spares diagnostic thyroidectomies (DTs) by excluding benign diseases such as NH or not. METHODS: From June 1999 to May 2007, DTs were performed on 98 patients who had nodules suspicious of FN. High resolution sonographic findings are available for 53 patients. According to the final histologic diagnosis: Group I (23 patients) consisted of 20 FNs (11 FTCs), 1 Hurthle cell adenoma, 2 FVPC; Group II (30 patients) consisted of all others (23 NHs, 4 Hashimoto's thyroiditis, 3 papillary carcinomas (PTCs). Sonographic features were compared between the two groups. RESULTS: Three differential sonographic findings (DSF) i.e. irregular margin, absence of peripheral halo or marked inhomogeniety were identified more often in Group II than Group I (P<0.05). If we spared DTs for patients who have at least one DSF, 18 patients (34.0%) would have been selected for clinical follow-up whose final diagnoses were 14 NHs and 4 PTCs (including 1 FVPC). Sparing DTs by DSFs shows sensitivity, 56.7%; specificity, 95.7%; positive predictive value, 94.4%; negative predictive value, 62.9%; and accuracy, 73.6%, respectively. CONCLUSION: In patients with thyroid nodules suspicious of FN, sonographic findings such as irregular margin, absence of peripheral halo or marked inhomogeneity might spare DTs with the help of other diagnostic modalities such as cytogenetic or immunohistochemical studies.

Postoperative Findings of the Cytological Diagnosis of Follicular Neoplasm or Hurthle Cell Neoplasm and the Risk of Malignancy

BACKGROUND: Follicular neoplasm (FN) or Hurthle cell neoplasm (HN) is a less well understood pitfall when evaluating thyroid nodule with fine-needle aspiration (FNA). This study aimed to determine the rates of malignancy and the predictive factors for malignancy in thyroid nodules with a cytological diagnosis of FN or HN. METHODS: The patients who were cytologically diagnosed as having FN or HN after FNA between 1995 and 2004 at Asan Medical Center were included in this study. We collected the pathology data until 2009 and we analyzed the clinical characteristics associated with malignancy. RESULTS: A total 478 patients were cytologically diagnosed as having FN or HN during the study period and 327 (68%) among them underwent thyroid surgery. Thyroid malignancy was confirmed in 157 (48%) of 327 patients. Malignancy was confirmed in 124 patients with FN (124/253, 49%). They were 48 papillary, 65 follicular, 7 Hurthle cell and 3 medullary carcinomas and 1 anaplastic carcinoma. The malignancy in the cases of HN (33/71, 44.6%) was 9 papillary, 4 follicular and 20 Hurthle cell carcinomas. The risk of malignancy was not associated with male gender, a larger tumor size (> 4 cm) or the diagnosis of HN. However, an age below 20 years (RR 3.6, P = 0.03) and above 60 years (RR 2.3, P = 0.04) was associated with an increased risk of malignancy. CONCLUSION: About half of the patients with FN or HN on FNA cytology were diagnosed as having thyroid cancer after surgery. The malignancy rate for the cytologic diagnosis of HN was similar to that for FN. Thyroid surgery should be recommended for this situation, and especially for patients younger than 20 years or older than 60 years.

Avaliação pré-operatória com PET-18F-FDG de nódulos de tireóide com citologia indeterminada / Preoperative evaluation of cytologically indeterminate thyroid nodules with 18F-FDG PET

Esse artigo tem o objetivo de discutir o papel da tomografia por emissão de pósitrons (PET) com 18F-FDG na avaliação pré-operatória de pacientes com nódulos de tireóide com citologia indeterminada. Para o cálculo da sensibilidade, foram selecionados todos os estudos com pacientes com carcinoma de tireóide. Para o cálculo da especificidade, foram selecionados apenas estudos desenhados para avaliação dos pacientes com nódulos com citologia indeterminada. O achado de captação focal na PET-18F-FDG relacionou-se com a presença de carcinoma de tireóide na maioria dos estudos. A sensibilidade do exame foi bastante alta na detecção de malignidade tireoidiana, porém sua especificidade variou de 0 por cento a 66 por cento, sendo de 39 por cento em estudo brasileiro. Concluindo, os estudos indicam que a PET-18F-FDG pode reduzir o número de tireoidectomias desnecessárias em pacientes com nódulos de tireóide com citologia indeterminada. Entretanto, o percentual relativamente elevado de resultados falso-positivos, o alto custo, a baixa disponibilidade do exame em países em desenvolvimento e a pouca experiência clínica ainda limitam o uso da PET-18F-FDG com essa finalidade.

The aim of this article is to discuss the role of 18F-FDG Positron Emission Tomography (PET) in the preoperative evaluation of patients with cytologically indeterminate thyroid nodules. All studies with patients with thyroid cancer were selected to the calculation of sensitivity. Only studies aiming to evaluate patients with thyroid nodules whose cytological result was indeterminate were selected to establish the specificity. The finding of focal 18F-FDG uptake at PET was associated with the presence of thyroid malignancy in most of the studies. The sensitivity of the exam to the detection of thyroid malignancy was extremely high, but the specificity varied from 0 to 66 percent. In our experience, the specificity was 39 percent. In conclusion, the studies suggest that 18F-FDG PET can reduce the number of unnecessary thyroidectomies performed in patients with cytologically indeterminate thyroid nodules. However, the relatively high percentage of false positive results, the high costs, the low availability of this exam in developing countries and the low clinical experience still restrict the use of 18F-FDG PET when recommended with this aim.

Fine Needle Aspiration Cytology of Parathyroid Neoplasms: A Review of Three Cases / 대한세포병리학회지

Parathyroid tumors may be difficult to distinguish from thyroid follicular lesions, especially when a tumor is nonfunctioning. We report here two cases of asymptomatic parathyroid carcinoma preoperatively misdiagnosed as thyroid follicular lesions, and one case of parathyroid adenoma showing hyperparathyroidism, and review the cytologic features favoring the diagnosis of parathyroid neoplasm. The cytologic findings that are characterized by clean background, monomorphic small cells, cohesive three-dimensional papillary clusters, small tight clusters with scattered naked nuclei, and well-defined clear cytoplasm favor a diagnosis for the parathyroid lesions. Cytologic findings such as macrofollicular structure, presence of colloid and macrophages, and presence of perivacuolar cytoplasmic granules on May-Grunwald-Giemsa stain support a diagnosis of a thyroid follicular lesion. The cytomorphology of parathyroid tumors is so variable that the distinction from a thyroid lesion cannot be based on the presence or absence of a single feature only but on the cytologic features as a whole.

Diagnostic Effects of Fine Needle Aspiration Cytology and Frozen Section for Follicular Neoplasm of the Thyroid

PURPOSE: To determine diagnostic effects of fine needle aspiration cytology (FNA) and frozen section of thyroid follicular neoplasm and its role in the therapeutic approach. METHOD: We performed a retrospective analysis of the data of patients who underwent thyroid surgery at the Gwangju Christian Hospital, between March 2000 and December 2004, and had a report of preoperative fine needle aspiration (FNA) biopsy of thyroid follicular lesions, which comprises cellular lesion, suspicious for follicular neoplasm or follicular carcinoma. RESULTS: Out of 45 patients with preoperative FNA biopsy diagnosis of follicular neoplasm, reveals true follicular carcinoma in 20 (44.4%), a follicular adenoma in 11 (24.5%), a papillary carcinoma in 7 (15.5%), a papillary carcinoma with follicular variant in 4 (8.9%), an adenomatous goiter in 3 (6.7%). Among the 45 patients having an intraoperative frozen sections, only 7 patients (15.5%) were true follicular carcinoma, suspicious for malignant follicular neoplasm in 14 patients (31.1%) and suspicious for benign follicular neoplasm in 8 patients (17.8%). final diagnosis were changed from suspicious for benign follicular neoplasm at intraoperative frozen section to malignant in 3 patients, from suspicious for malignant follicular neoplasm to benign in 1 patient. Three patients underwent a lobectomy and 1 patients a subtotal thyroidectomy followed by a completion thyroidectomy. CONCLUSION: Fine needle aspiration cytology and frozen section results are not good indicators in making the decision of operative extent. the best way to establish a diagnosis and to predict prognosis is to surgically remove the tumor for a proper histopathologic examination.

Postoperative Findings and Risk for Malignancy in Thyroid Nodules with Cytological Diagnosis of the so-called "Follicular Neoplasm"

BACKGROUND: Malignant follicular lesion is not differentiated from benign lesions cytologically. The objective of this study was to assess the rate and the risk of malignancy in thyroid nodules which were cytologically diagnosed as follicular neoplasm by fine-needle aspiration (FNA) cytology. METHODS: All the patients who had undergone surgery with cytological diagnosis of follicular neoplasm from January 1996 through December 2001 in Asan Medical Center were studied retrospectively. Patients' and nodule characteristics were analyzed for factors associated with the presence of cancer. Two hundred and fifteen patients (196 females, 19 males) were included and their mean age was 39.4 years (range: 12~76). RESULTS: About half of the patients (102 out of 215, 47.4%) had malignancy with 29 papillary carcinomas, 57 follicular carcinomas, 15 H rthle cell carcinomas and 1 medullary carcinoma. Previously suggested factors associated with risk for malignancy, such as male gender, large tumor size (> 4 cm) or age of patients (> 45 years), were not associated with increased risk. Diagnosis of H rthle cell neoplasia on FNA was also not associated with increased risk. Only the extremes in age of the patients (below 20 or above 60 years) were associated with increased risk for malignancy. CONCLUSION: In our findings, prevalence of carcinoma in thyroid nodule patients with cytological diagnosis of follicular neoplasm was much higher than those reported. Clinical characteristics, such as male gender, age and nodule size, are not useful predictors for the presence of malignancy. Thyroid nodules with cytological diagnosis of follicular neoplasm warrant immediate surgery.