Clinical and histopathological features of follicular thyroid cancer in Chile

ABSTRACT Objective: Follicular thyroid carcinoma (FTC) is less frequent but has a worse prognosis than papillary carcinoma. The available evidence on pre-operative characteristics of FTC is controversial. Our objective was to characterize the clinical, ultrasound and histopathological presentation of FTC patients treated Chile. Subjects and methods: Retrospective analysis of 97 patients treated for FTC in 6 large centers in Chile. We analyzed their ultrasonographic features and classified the nodules according to ATA risk of malignancy and TI-RADS score, as well as the cytological findings according to the Bethesda system. We described their clinical and histopathological findings at diagnosis and classified their risk of recurrence and mortality according to ATA 2015 recurrence risk category and the eighth edition of the AJCC/UICC staging system, respectively. Results: Median age was 48 years and 73.2% were females. The median diameter was 38.8 mm; only 9.5% of them were microtumors. According to ATA risk of malignancy, 86% of the nodules were low or intermediate suspicious, while 78% were category 3 or 4A nodules according to the TI-RADS. Regarding the Bethesda system, 65.9% had indeterminate cytology (20.6% category III and 45.3% category IV). At histological examination, most were minimally-invasive and angio-invasive tumors with less than 4 foci (54.7% and 28.4% respectively). More than 90% of FTC were unifocal and there was no lymphovascular or extrathyroidal invasion or lymph node involvement. Four patients (4.1%) had distant metastases at diagnosis. Most patients (95%) had stage I or II disease according to the AJCC/UICC staging system, while the risk of recurrence was low at 51.5% when using the ATA risk of recurrence scale. Conclusions: At diagnosis, most FTCs were nodules of low or intermediate suspicion at ultrasound, nearly two thirds had indeterminate cytology according to the Bethesda system, and nearly 50% of them were of low risk of recurrence.

Warthin-like and classic papillary thyroid cancer have similar clinical presentation and prognosis

ABSTRACT Objective Warthin-like papillary thyroid cancer (WL-PTC) is an uncommon variant of PTC, usually associated with lymphocytic thyroiditis. Scarce evidence suggests that WL-PTC has similar clinical presentation to classic PTC (C-PTC), with no studies comparing risks of recurrence and response to treatment between both variants. Our objective was to describe the clinical presentation and prognosis of WL-PTC and compare it to C-PTC. Subjects and methods Retrospective analysis of a prospective cohort, including 370 (96%) patients with C-PTC and 17 (4%) with WL-PTC, consecutively treated with total thyroidectomy with or without RAI, followed for at least 6 months. We compared clinical presentation, risk of mortality and recurrence, as well as response to treatment between both variants. Results Of the total cohort: 317 (82%) female, 38 ± 13.5 years, median follow-up 4 years (0.5-28.5); most of them stage I and low/intermediate risk of recurrence. We found no differences regarding clinical-pathological data and risk of recurrence. WL-PTC was associated with a higher rate of anti-thyroglobulin antibodies (TgAb) (65% vs. 36%, p = 0.016) and lymphocytic thyroiditis (59% vs. 34%, p = 0.03). The rates of biochemical and structural incomplete responses were similar in both variants. WL-PTC had a lower rate of excellent response (23% vs. 54%, p = 0.01), which became non-significant when performing analysis by TgAb presence (50% vs. 67%, p = NS). Conclusions WL-CPT and C-CPT have similar clinical presentation and rate of recurrence. The lower rate of excellent response to treatment in WL-PTC is due to a higher frequency of TgAb. WL-PCT should not be considered an aggressive variant of PTC.

Metástasis pancreática como debut de carcinoma papilar de tiroides: caso clínico y revisión del perfil clínico patológico y molecular / Papillary thyroid carcinoma presenting with pancreatic metastases: report of one case

Pancreatic metastases of papillary thyroid carcinoma (PTC) are exceptional. We report a 80-year-old man consulting for obstructive jaundice and dysphonia. Abdominal ultrasonography showed biliary dilation and abdominal magnetic resonance imaging (MRI) showed a pancreatic head mass of 36 mm. A left vocal cord paralysis was confirmed and cervical computed tomography (CT) showed multiple thyroid nodules of up to 35 mm associated with bilateral cervical lymph nodes (LN). Positron emission tomography ( 18 F-FDG PET/CT) evidenced hyper-metabolic activity in bilateral cervical LN, lungs, pancreas and left intercostal soft tissue, as well as left gluteus. Thyroid biopsy reported a tall-cell variant of PTC, and endoscopic ultrasound guided fine needle aspiration (EUS-FNA) of pancreatic mass confirmed PTC metastasis. The molecular study was positive for BRAFV600E. Pancreatic metastasis from PTC can be accurately diagnosed with 18 F-FDG PET/CT and EUS-FNA, which is consistent with a predominant expression of BRAFV600E mutation and, thus, an aggressive presentation with poor short-term survival.

Manejo de nódulos tiroideos y cáncer de tiroides con lobectomía: experiencia de un equipo multidisciplinario / Management of thyroid nodules and thyroid cancer with lobectomy: experience of a multidisciplinary team

INTRODUCCIÓN: La extensión de la cirugía es motivo de controversia en el manejo de nódulos y cáncer diferenciado de tiroides (CDT). En nódulos benignos e indeterminados que requieran cirugía, la lobectomía es de elección, mientras que en CDT debe considerarse en tumores intratiroideos ≤ 4 cm. NUESTRO OBJETIVO objetivo fue reportar la primera cohorte chilena de nódulos tiroideos y CDT tratados con lobectomía por un equipo multidisciplinario. SUJETOS Y MÉTODOS: Se incluyeron pacientes sometidos a lobectomía por nódulos tiroideos y CDT que cumplieran: 1) tumor intratiroideo ≤4cm si punción aspirativa (PAF) Bethesda I, III, IV, V o VI; sin límite de tamaño si PAF Bethesda II, y 2) sin hallazgos sospechosos en la ecografía preoperatoria. En pacientes con CDT se describió presentación clínica, complicaciones y tipo de respuesta a tratamiento según ATA 2015 y MINSAL 2020. RESULTADOS: Se incluyeron 105 pacientes, edad 38±11 años, 84 (80%) mujeres, diámetro 2,2±1,5cm: 41 (39%) benignos y 64 (61%) CDT. De los CDT, 44 (69%) tenían cáncer papilar, 7 (11%) cáncer folicular y 13 (20%) NIFTP. Todos eran etapa I. Según MINSAL, 55 (85,9%) de riesgo muy bajo/bajo y 9 (14,1%) intermedio. Según ATA, 51 (80%) y 13 (20%) de riesgo bajo e intermedio, respectivamente. Se indicó totalización precoz y ablación con radioyodo en 6 (9,4%) pacientes: 4 por invasión venosa y 2 por CPT variedad sólida. De los 39 no totalizados seguidos ≥6 meses, no hubo casos de respuesta incompleta. Respecto a las complicaciones, ningún paciente tuvo hipocalcemia y 10 (9,5%) tuvieron disfonía transitoria. CONCLUSIONES: En pacientes con nódulos tiroideos o CDT seleccionados, la lobectomía es una alternativa adecuada. En CDT logra buen control de enfermedad sin necesidad de tratamiento adicional en cerca de 90% de los pacientes, con muy baja morbilidad asociada.

INTRODUCTION: The extension of surgery is a matter of debate in the management of thyroid nodules and differentiated thyroid cancer (DTC). While lobectomy is the procedure of choice in benign and indeterminate nodules that require surgery, it is an option in intrathyroidal DTC up to 4 cm. OUR OBJECTIVE was to report the first Chilean cohort of patients with thyroid nodules and DTC treated with lobectomy by a multidisciplinary team. SUBJECTS AND METHODS: We included patients with thyroid nodules treated with lobectomy, who met the following inclusion criteria: 1) intrathyroidal tumor ≤ 4cm if fine-needle aspiration biopsy (FNA) was Bethesda I, III, IV, V o VI; without size limit if FNA was Bethesda II, and 2) non-suspicious findings in preoperative ultrasound. In patients with DTC we described clinical presentation, complications and response to treatment according to ATA 2015 and MINSAL 2020. RESULTS: We included 105 patients, 38±11 years old, 84 (80%) female, diameter 2.2±1.5cm: 41 (39%) benign and 64 (61%) DTC. Among DTC, 44 (69%) had papillary thyroid cancer, 7 (11%) follicular thyroid cancer and 13 (20%) NIFTP. All had stage I DTC. According to MINSAL, 55 (85.9%) were very low/low, and 9 (14.1%) intermediate risk. According to ATA, 51 (80%) and 13 (20%) were low and intermediate risk, respectively. Six (9.4%) patients required early completion thyroidectomy and radioiodine ablation: 4 due to angioinvasion and 2 due to solid variant PTC. None of the 39 non-completed patients followed for at least 6 months had incomplete response. Regarding complications, there were no cases of hypocalcemia and 10 (9.5%) patients had transient dysphonia. CONCLUSIONS: In properly selected patients with thyroid nodules or DTC, lobectomy is an appropriate treatment option. In DTC, lobectomy accomplishes adequate disease control without need of further treatment in nearly 90% of patients, with very low associated morbidity.

Discrepancia en concentraciones de hormonas tiroideas libres medidas por distintos inmunoensayos / Discrepancy in concentrations of free thyroid hormones measured by different immunoassays

Abstract: Thyroid function is assessed by measuring thyrotropin and free and total thyroid hormone concentrations. There are interferences with the results of immunoassays that can lead to an incorrect diagnosis, of which the most frequent are the binding of thyroid hormones to heterophile antibodies, rheumatoid factor, anti-Ruthenium antibodies, the intake of biotin and anti-streptavidin antibodies. We present three cases of clinically euthyroid patients, with normal TSH, high free T4 and T3, and normal total T4 and T3 performed in a Roche Diagnostics ® COBAS 8000 device. When the test was repeated on a Siemens® Immulite device, the free and total hormones were within normal ranges. In the Roche Diagnostics ® assay, the presence of biotin or anti-Ruthenium or anti-streptavidin antibodies interferes with the formation of the complex responsible for the emission of light that allows inferring concentrations of thyroid hormones. The Siemens test works differently since the emission of light depends on the binding of T4 to an antibody conjugated with alkaline phosphatase not participating in the process biotin, streptavidin or ruthenium so this interference is avoided. This possible interference in immunoassays should be taken into account in case clinical manifestations differ from these laboratory determinations, to avoid a diagnosis and potential inappropriate treatment.

Resumen: La función tiroidea se evalúa midiendo tirotropina y concentraciones de hormonas tiroideas libres y totales. Existen interferencias con los resultados de inmunoensayos que pueden llevar a un diagnóstico incorrecto, de ellas, las más frecuentes son la unión de hormonas tiroideas a anticuerpos heterófilos, el factor reumatoide, anticuerpos anti Rutenio, la ingesta de biotina y anticuerpos anti estreptavidina. Se presentan tres casos de pacientes clínicamente eutiroideos, con TSH normal, T4 y T3 libres elevadas, y T4 y T3 totales normales realizadas en un equipo COBAS 8000 de Roche Diagnostics®. Cuando se repitió el ensayo en un equipo Immulite de Siemens®, las hormonas libres y totales estaban dentro de rangos normales. En el ensayo de Roche Diagnostics ®, la presencia de biotina o anticuerpos anti Rutenio o anti estreptavidina, interfiere con la formación del complejo responsable de la emisión de luz que permite inferir las concentraciones de las hormonas tiroideas. El ensayo de Siemens funciona de manera diferente ya que la emisión de luz depende de la unión de la T4 a un anticuerpo conjugado con fosfatasa alcalina no participando en el proceso biotina, estreptavidina o Rutenio por lo que se evita esta interferencia. Esta posible interferencia en inmunoensayos debe ser tenida en cuenta en caso de que las manifestaciones clínicas difieran de estas determinaciones de laboratorio, para evitar un diagnóstico y potencial tratamiento inadecuado.

Riesgo de recurrencia en cáncer diferenciado de tiroides: escala MINSAL / Risk of recurrence in differentiated thyroid cancer

Background: Differentiated thyroid cancer (DTC) is generally associated with a favorable prognosis. Its treatment requires surgery, selective use of radioiodine and levothyroxine, and its intensity must be adjusted to the initial risks of mortality and recurrence. Aim: To validate the risk of recurrence classification developed by the Chilean Ministry of Health in 2013 (MINSAL 2013), and compare it with the American Thyroid Association (ATA) 2009 and 2015 classifications. Material and Methods: Retrospective study of 362 patients with DTC aged 44.3 ± 13.4 years (84% women), treated with total thyroidectomy, selective radioiodine ablation and levothyroxine and followed for a median of 4.2 years (range 2.0-7.8). Risk of recurrence was estimated with MINSAL 2013, ATA 2009 and ATA 2015 classifications, and risk of mortality with 7th and 8th American Joint Committee on Cancer (AJCC)/TNM systems. Clinical data obtained during follow-up were used to detect structural and biochemical persistence/recurrence. Results: A mean dose of 104 ± 48 mCi radioiodine was received by 91% of patients. MINSAL 2013 classified 148 (41%), 144 (40%), 67 (19%) and 3 (1%) patients as very low, low, intermediate and high risk of recurrence, respectively. Forty-five (12.4%) patients had persistence or recurrence during follow-up: 33 structural and 12 biochemical. Rates of persistence/recurrence on each category of MINSAL 2013 were 4.1%, 7.6%, 37.3% and 100%, respectively (p < 0.01). Areas under Receiver Operating Characteristic curves for persistence or recurrence of MINSAL 2013, ATA 2009 and ATA 2015 were 0.77 vs 0.73 vs 0.72, respectively. Conclusions: MINSAL 2013 classifies appropriately DTC patients and estimates correctly their risk of persistence or recurrence.

Del macro al microcarcinoma tiroideo: cambios en las características de presentación del cáncer de tiroides en un centro universitario chileno en 20 años / From macro to micro thyroid carcinoma: records of a clinical hospital from 1991 to 2010

Background: The prevalence of thyroid cancer has increased, particularly in nodules smaller than 10 mm, probably due to the growing use of routine thyroid ultrasound. There is controversy about the biological behavior of micro carcinomas and the relevance of their early detection. Aim: To characterize the clinical presentation of thyroid cancer over 20 years in an University medical center and to evaluate the differences between macro and micro carcinomas. Patients and Methods: We reviewed 1547 surgical biopsy records of thyroid cancer in our institution obtained between 1991 and 2010. Results: We observed a sustained increase in the rate of thyroidectomies for thyroid cancer (per 1000 surgical procedures) in the study period. Papillary, follicular, mixed, medullary and anaplastic carcinomas were observed in 95, 3, 2, 0.5 and 0.1% of biopsies, respectively. The incidence of tumors of less than 10 mm (micro carcinoma) also increased. Those findings were associated with a significant decrease in tumor aggressiveness, determined by a low frequency of surgical margin involvement of thyroid capsule, perithyroid tissue invasion, vascular permeation and lymph node metastases. Conclusions: The increased prevalence of thyroid cancer, especially of micro carcinomas, may reflect the greater use of diagnostic ultrasound or represent a real change in the biological behavior of this disease and our data suggest that further studies are needed to know the impact of early treatment in the outcome of those patients because of the real less histologic agressiveness of micro carcinomas.

Utilidad de la PTH intraoperatoria como predictor de curación quirúrgica en hiperparatiroidismo primario / Usefulness of intraoperative parathormone measurement to predict surgical cure in primary hyperparathyroidism

Background: The aim of the surgical treatment of primary hyperparathyroidism (PHPT) is to achieve its complete cure, evidenced by normal serum calcium in the postoperative period. Measurement of intraoperative serum parathormone (PTH) can be useful to predict complete cure of the disease. Aim: To assess the usefulness of intraoperative PTH measurement to predict complete cure of PHPT Material and methods: Serum PTH was measured to all patients operated for PHPT between 2003 and 2008, before and five and ten minutes after the excision of the parathyroid gland causing the disease. The criteria for complete cure were normal serum calcium at 24 hours and 6 months after surgery and the pathological confirmation of parathyroid gland excision. Results: Eighty-eight operated patients, aged 58±15 years (72 females) were studied. Sixty four percent were asymptomatic and their preoperative serum calcium was 11.6± 1.2 mg/dl. A normal serum calcium was achieved in 86 patients (98 percent) at 24 hours and 50 of 52 patients followed for six months (96 percent). The pathological study disclosed an adenoma in 69 (78 percent), and multiglandular disease in 16 (18 percent), a parathyroid cancer in one and a normal gland in one patient. Intraoperative PTH predicted early and definitive cure in 97 percent and 100 percent of patients with a single adenoma, respectively. Among patients with multiglandular disease, the predictive figures were 94 percent and 100 percent, respectively. Conclusions: Intraoperative PTH measurement efficiently predicts early and definitive surgical cure of PHPT.

Diseño de una escala ecográfica predictora de malignidad en nódulos tiroideos: Comunicación preliminar / An ultrasound score to predict the presence of papillary thyroid carcinoma: Preliminary report

Background: Thyroid nodules are common and associated to a low risk of malignancy. Their clinical assessment usually includes a fine neddle aspiration biopsy (FNAB). Aim To identify ultrasonographic characteristics associated to papillary thyroid carcinoma (PTC) and generate a score that predicts the risk of PTC. Material and methods: Retrospective review of all fine needle aspiration biopsies of the thyroid performed in a lapse of two years. Biopsies that were conclusive for PTC were selected and compared with an equal amount of randomly selected biopsies that disclosed a benign diagnosis. Results: One hundred twenty two biopsies of a total of 1,498 were conclusive for PTC. Univariate analysis showed associations with PTC for the presence of micro-calcifications (Odds ratio (OR) 49.2: 95 percent confidence intervals (CI) 18.7-140.9), solid predominance (OR 25.1; 95 percent CI 6-220), hypoechogenicity (OR 23.5, 95 percent CI 6.5-122.6), irregular borders (OR 17, 95 percent CI 7.2-42.9), lymph node involvement (OR 12.3, 95 percent CI2.7-112), central vascularization (OR 12.2, 95 percent CI 4.8-33.3), local invasion and hyperechogenicity (OR 0.2; CI95 percent CI 0.03-0.6). Multivariate analysis disclosed microcalcifications (OR 28.1; CI 95 percent 8.9-89), hypoechogenicity (OR 9.4; 95 percent CI 1.5-59.5) and irregular borders (OR 4.7; CI 95 percent 1.5-15) as the variables independently associated with the presence of PTC. The prevalence of PTC in the presence of the three variables was 97.6 percent (Likelihood ratio (LR) 45) and 5.4 percent in their absence (LR 0.06). Conclusions: This scale predicts the presence or absence of PTC using simple ultrasound characteristics.