Prevalence and clinical significance in our setting of incidental uptake in the thyroid gland found on 18F-fluordeoxyglucose positron emission tomography-computed tomography (PET-CT).

INTRODUCTION: The expanding use of 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) has resulted in an increased frequency of incidentally discovered areas of FDG uptake within the thyroid gland. In these incidentalomas, high malignancy rates are reported. The study aimed, on the one hand, to determine the prevalence in our setting of thyroid incidentalomas in patients with no previous history of thyroid cancer undergoing an FDG PET-CT as well as the risk of malignancy and, on the other hand, to evaluate the usefulness of the maximum standard uptake value (SUVmax) for detecting thyroid cancer. MATERIAL AND METHODS: The FDG PET-CT scans performed at our hospital between June 2013 and December 2020 were retrospectively reviewed. In those incidentalomas with sufficient additional investigation, a diagnosis of benign or malignant was established based on the complementary tests. RESULTS: From the 21,594 PET-CT scans performed, 398 (1.8%) patients had an incidental FDG uptake, either focal (n=324) or diffuse (n=74). Among incidentalomas with further investigation, the rate of malignancy was higher in patients with focal FDG uptake than in those with diffuse uptake (26.5% versus 4%, respectively, p<0.05). The SUVmax value was significantly lower in benign focal lesions (5.7 [range: 2.3-66] than in malignant ones 10.6 [range: 3.1-51.2]; p<0.05). Nearly a quarter of malignant diagnoses (23.3%) were related to potentially aggressive tumours. CONCLUSION: The high rate of malignant tumours found among PET-CT incidentalomas and the high proportion of aggressive tumours demonstrate the need for a standardised approach in the investigation of incidental focal FDG uptake in the thyroid gland.

Sudden cardiac death in persons aged 50 years or younger: diagnostic yield of a regional molecular autopsy program using massive sequencing.

INTRODUCTION AND OBJECTIVES: Sudden cardiac death (SCD) in young people often has a genetic cause. Consequently, the results of "molecular autopsy" may have important implications for their relatives. Our objective was to evaluate the diagnostic yield of a molecular autopsy program using next-generation sequencing. METHODS: We performed a prospective study of a cohort of consecutive patients who died from nonviolent SCD, aged ≤ 50 years, and who underwent molecular autopsy using large panels of next-generation sequencing, with subsequent clinical and genetic family screening. We analyzed demographic, clinical, toxicological, and genetic data. RESULTS: We studied 123 consecutive cases of SCD in persons aged ≤ 50 years. The incidence of SCD was 5.8 cases/100 000 individuals/y, mean age was 36.15±12.7 years, and 95 were men (77%). The cause was cardiac in 53%, unexplained SCD in 24%, toxic in 10.6%, and infant SCD in 4%. Among cardiac causes, ischemic heart disease accounted for 38% of deaths, arrhythmogenic cardiomyopathy for 7%, hypertrophic cardiomyopathy for 5%, and idiopathic left ventricular hypertrophy for 11%. Genetic analysis was performed in 62 cases (50.4%). Genetic variants were found in 42 cases (67.7%), with a mean of 3.4±4 genetic variants/patient, and the variant found was considered to be pathogenic or probably pathogenic in 30.6%. In unexplained SCD, 70% showed some genetic variant. Family screening diagnosed 21 carriers or affected individuals, 5 of whom were at risk, indicating an implantable cardiac defibrillator. CONCLUSIONS: Protocol-based and exhaustive study of SCD from cardiac causes in persons aged ≤ 50 years is feasible and necessary. In a high percentage of cases, the cause is genetic, indicating the existence of relatives at risk who could benefit from early diagnosis and treatment to avoid complications.