Castiglioni, T. 1; Paparatto, A. 2; Elsner, B. 3
Se analizan dos series de resecciones tiroideas, una de 2147 casos efectuada entre los años 1958 y 1976 y la otra de 2236 casos entre 1988 y 2000. Se halló una incidencia mayor de tumores malignos en la segunda serie, (7.5% vs 26.2%). La tipificacion de los carcinomas varió con una mayor incidencia de carcinomas papilares en serie actual, los que pasaron del 54% al 79.8%y una disminución de los carcinomas foliculares (18 al 7.5%) y de los indiferenciados (14.3% al 3.4%). La frecuencia de los carcinomas de Hürthle no varió significativamente (3.7% al 3.4%). Dos tercios de los carcinomas foliculares y de Hürthle correspondían a la variedad encapsulada y el tercio restante a tumores invasores. Se concluye que la mejor selección preoperatoria de los pacientes ha cambiado por completo la frecuencia de cáncer en los pacientes que son operados. Además, la escasa frecuencia de carcinomas foliculares hace que el término de «neoplasia folicular » tenga poco uso actualmente siendo mejor reemplazarlo por el de «nódulo folicular hipercelular» el que corresponderá en la mayoría de los casos a adenomas foliculares o nódulos microfoliculares de un bocio nodular.
Two surgical series of thyroid specimens were analized and compared. The first one was composed of 2147 cases operated upon between 1958 and 1976 and the second one 2236 cases operated upon 1988 and 2000. All the histological slides were reviewed and reclassified according to current criteria. Immunostains from new sections done from the paraffin blocks were done when indicated, mainly in cases of medullary carcinomas, undifferentiated carcinomas and lymphomas. Few recent cases of malignant lymphomas were also studied by flow cytometry. Among the benign lesions we found an increase in the follicular adenomas (34.3% and 43.8%) and a decrease in the Hashimoto’s thyroiditis (10.1% and 4.8%) and Graves disease (3.9% and 2.4%). We found an increase in the malignant tumors in the second series (7.5 vs 26.2%). The histological type of cancers were also different with an increase of papillary carcinomas that varied from 54% of all cancers in the first series to 79.8% in the second. Follicular carcinomas decreased from 18% in the first series to 7.5% in the second. Hürthle cell carcinomas remained constant (3.7% and 3.4%). Two thirds of follicular and Hürthle cell carcinomas were of the encapsulated type. Undifferentiated carcinomas decreased from 14.3% to 3.4% due partially to the fact that in many of these cases the diagnosis is made now with a fine needle aspiration and they are not opeated upon. Medullary carcinomas remained fairly constant (6.2% and 5.3%). It is concluded that a better selection of the patients brought to surgery changed completely the incidence of cancer found in surgical specimens. The main procedure responsible of this is the widespread use of fine needle aspiration biopsy that was begun at our institution in 1977. It is also suggested that because of the rarity of follicular carcinomas and the fact that two thirds of them will be encapsulated the cytological diagnosis of «follicular neoplasm» is of no great use in this setting as only 6% of the solitary follicular lesions turned to be carcinomas, two thirds of them of the encapsulated variety. It is better designate this lesions as «follicular hypercelular nodules» encompassing microfollicular adenomas, adenomatous nodules with a microfollicular pattern and the few follicular carcinomas that will be found. In the case of Hürthle cell tumors the situation is completely different as 20% of them turned out to be malignant after resection so a cytological diagnosis of Hürthle cell tumor is an indication for its surgical removal. Among our cases the infrequent thyroid lesions were truly rare: There were only four cases of metastatic lesions, three of them from the kidney, nine malignant lymphomas, and one insular carcinoma. Among the benign lesions there were only two cases of de Quervain’s thyroiditis.