Optimizing Diagnostic Accuracy of Fine Needle Aspiration Biopsy Calcitonin Measurements in Detecting Medullary Thyroid Carcinoma.

Background: The optimal cutoff value of calcitonin (Ctn) levels measured using an electrochemiluminescence immunoassay (ECLIA) obtained from the washout fluid of fine needle aspiration (FNA-Ctn) for the diagnosis of medullary thyroid carcinoma (MTC) is currently not established. We evaluated the diagnostic accuracy and clinical utility of FNA-Ctn for the diagnosis and location of MTC in patients with nodular or multinodular goiters. Methods: This was a case-control study nested on a prospective multicenter cohort of patients with nodular or multinodular goiter, normal or elevated serum Ctn, and thyroidectomy indications. Ctn and FNA-Ctn were measured using ECLIA methodology before surgery. From this nested cohort, MTC cases and controls (non-medullary pathology) were identified from the final pathological analysis. Cumulative incidence sampling of controls was randomly performed at a ratio of 1:2. Sensitivity, specificity, and area under the receiver operator curve (AUROC) were calculated for patients and the total number of thyroid nodules. Results: From 1272 patients included in the prospective cohort, 50 MTC cases and 105 controls were included. In this study, 286 thyroid nodules were evaluated (63 MTC and 223 non-MTCs). The median serum Ctn value was significantly higher in cases (525 pg/mL [interquartile range (IQR), 162.5-1.200]) than in controls (1.6 pg/mL [IQR, 0.5-5.6]; p < 0.001). The median FNA-Ctn value was significantly higher in MTC nodules (3.100 pg/mL [IQR, 450-45,200]) than in non-MTC nodules (0.5 pg/mL [IQR, 0.5-0.5]; p < 0.0001). In 11 MTC patients with multinodular goiter, the FNA-Ctn value was significantly higher in non-medullary nodules located in the same lobe where an MTC nodule was diagnosed (p = 0.0002). Overall, the FNA-Ctn AUROC was 0.99 [95% confidence interval, 0.98-1.0], and a threshold of ≥220 pg/mL showed 100% sensitivity and 98% specificity for MTC diagnosis. Conclusions: The use of FNA-Ctn measured by ECLIA showed adequate diagnostic accuracy for MTC diagnosis. Moreover, it may be clinically useful for localization in multinodular goiter when lobectomy is considered. Clinical Trial Registration: Clinicaltrials.gov NCT06067594.

Non-invasive follicular neoplasm with papillary-like nuclear features: a challenging and infrequent entity in Argentina.

PURPOSE: Non-invasive encapsulated follicular variant of papillary thyroid cancer was reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). These neoplasms have an extremely low malignant potential. The aim of this study was (1) to assess the prevalence of NIFTP in patients with papillary thyroid carcinoma, (2) to evaluate their outcomes, and (3) to determine their molecular profile. METHODS: Multicenter, descriptive, retrospective study. Patients with papillary thyroid cancer diagnosed from January 2006 to December 2016 from 11 referral centers were included. Diagnosis of NIFTP was based on criteria described by Nikiforov et al. in 2018. At least two pathologists agreed on the diagnosis. Two thousand six hundred and seventy-seven papillary thyroid cancer patients were included; 456 (17%) of them were follicular variant papillary thyroid cancer, and 30 (1.12%) fulfilled diagnostic criteria for NIFTP. RESULTS: Each of the 30 included patients underwent a total thyroidectomy, and 50% were treated with radioiodine (median dose 100 mCi). After a median follow-up of 37 months, 84% of patients had an excellent response, 3% had an indeterminate response and data was missing in the remaining 13%. No metastatic lymph nodes, distant metastases or recurrences were found. RAS mutations were detected in 4 patients (13%). CONCLUSION: The prevalence of NIFTP in our series is amongst the lowest reported. Excellent outcomes of patients underscore their low malignant potential. Molecular findings differ from other series, probably related to environmental or ethnic features of our population and the meticulous criteria for diagnosing NIFTP.

Necrosis isquémica subendocárdica en un paciente con síndrome urémico hemolítico (SUH) / Subendocardial schemic necrosis in an infant with hemolytic-uremic syndrome

El síndrome urémico hemolítico es una enfermedad multiorgánica y con pronóstico variable según sea la forma clásica con diarrea o sin ella. Se lo reconoce por su alta morbilidad (insuficiencia renal crónica). En el período agudo se describen casos fatales. Reportamos el caso de un niño de 23 meses de vida quien ingresó a UCIP con diagnóstico de SUH para diálisis peritoneal. Durante el séptimo baño de diálisis el paciente experimentó inquietud, desasosiego y paro cardiorespiratorio casi inmediatamente. El hallazgo necrópsico reveló necrosis isquémica subendocárdica

Necrosis isquémica subendocárdica en un paciente con síndrome urémico hemolítico (SUH) / Subendocardial schemic necrosis in an infant with hemolytic-uremic syndrome

El síndrome urémico hemolítico es una enfermedad multiorgánica y con pronóstico variable según sea la forma clásica con diarrea o sin ella. Se lo reconoce por su alta morbilidad (insuficiencia renal crónica). En el período agudo se describen casos fatales. Reportamos el caso de un niño de 23 meses de vida quien ingresó a UCIP con diagnóstico de SUH para diálisis peritoneal. Durante el séptimo baño de diálisis el paciente experimentó inquietud, desasosiego y paro cardiorespiratorio casi inmediatamente. El hallazgo necrópsico reveló necrosis isquémica subendocárdica (AU)