ABSTRACT
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.
Subject(s)
Humans , Biopsy, Fine-Needle , Diagnosis , Frozen Sections , Medical Records , Thyroid Gland , Thyroid Neoplasms , Thyroidectomy , UltrasonographyABSTRACT
INTRODUÇÃO: O exame intraoperatório por congelação tornou-se um procedimento de rotina na avaliação do linfonodo sentinela axilar no câncer de mama. OBJETIVOS: Avaliar a acurácia e a sensibilidade do FS na detecção de metástases em linfonodo sentinela axilar e investigar o valor preditivo para metástases de variáveis, como idade dos pacientes, estadiamento, tipo histológico, grau e expressão do receptor de estrogênio do tumor. MATERIAL E MÉTODOS: Foram analisados, retrospectivamente, os resultados de 177 procedimentos de congelação. A idade dos pacientes e as características dos tumores foram organizadas em um banco de dados e a relação com a presença de metástases foi analisada. RESULTADOS: Foram detectadas metástases em 22 (12%) casos. Todas as macrometastases e uma micrometastases foram detectadas pelo método de congelação. Micrometastases adicionais foram identificadas nas análises pós-operatórias, cinco por coloração com hematoxilina e eosina (H) e três por imuno-histoquímica. O método de congelação mostrou acurácia geral de 95%, sensibilidade de 64% e especificidade de 100%. Nenhuma associação significativa foi observada entre a presença de metástases e as variáveis analisadas. CONCLUSÃO: Nossos resultados mostram que o exame por congelação possui acurácia e sensibilidade elevadas para a detecção de macrometastases; no entanto, é pouco eficiente na identificação de micrometastases. O uso de imuno-histoquímica melhora a detecção de metástases na análise pós-operatória. A idade do paciente e as características do tumor, como estadiamento, tipo histológico, grau e a expressão do receptor de estrogênio têm de valor preditivo baixo para metástases nodais em câncer de mama.
INTRODUCTION: Intraoperative frozen section analysis has become a routine procedure to evaluate the status of axillary sentinel lymph nodes in breast cancer. OBJECTIVES: To evaluate the accuracy and sensitivity of FS in the detection of metastases in axillary sentinel lymph nodes and to investigate the predictive value of variables such as patients' age, tumor staging, histology, grade, and estrogen receptor expression. MATERIAL AND METHODS: We analyzed retrospectively the results of 177 FS procedures. The patients' age and tumor characteristics were organized in a database and the association with the presence of metastases was analyzed. RESULTS: Metastases were detected in 22 cases (12%). All macrometastases and one micrometastasis were detected by FS. Additional micrometastases were detected in post-operative analysis, from which five were determined by hematoxylin and eosin staining (H) and three by immunohistochemistry (IHC). FS diagnosis data proved to have an overall accuracy of 95%, sensitivity of 64%, and specificity of 100%. None of the analyzed variables showed significant association with lymph node metastases. CONCLUSION: Our results show that intraoperative FS is a highly accurate and sensitive method to detect macrometastases. However, it is inaccurate in the detection of micrometastases. The use of IHC improves the detection of micrometastases in postoperative analyses. The patient's age and tumor characteristics such as staging, histology, grade and estrogen receptor expression have low predictive value for lymph node metastasis in breast cancer.