Applicability of Fine-Needle Aspiration Biopsy of Lymph Nodes Using WHO Reporting System: Comparison between Pediatric and Adult Brazilian Populations

This study, despite the limited pediatric sample, demonstrates that the method is applicable to both pediatric and adult patients, including those outside cancer centers. The calculated ROM was 50% for inadequate, 32.6% for benign, 82.9% for suspicious, and 97.6% for malignant categories. Deviations from WHO reference intervals for inadequate and benign cases may be attributed to the absence of ancillary techniques. Then, two main findings emerged: (i) benign cytological diagnoses predominated in children, while suspicious and malignant results occurred exclusively in adults; and (ii) lymph nodes >2 cm were strongly associated with malignant cytological and histological outcomes.