Pathological prognostication of paediatric adrenocortical tumours: Is a gold standard emerging?

BACKGROUND: Criteria for the pathological classification of adult adrenocortical tumours (ACTs) have been found to overestimate the malignant potential of childhood ACTs. We sought to evaluate the accuracy and utility of criteria developed for paediatric ACT compared to current criteria for adults. METHODS: ACTs treated between January 2006 and December 2016 in two paediatric institutions were evaluated. Patients classified clinically as malignant (CM) had locally invasive disease at surgery requiring extensive en bloc resection to achieve clear margins, had local recurrence or distant metastasis. Slides were reviewed by pathologists blinded to the clinical outcome. A grade was assigned to each tumor according to the Weiss, Aubert, Wieneke and Dehner-Hill criteria. The pathological grade was compared to the clinical outcome. RESULTS: The median follow-up was 60 months (interquartile range 25-80 months). Based on clinical criteria, of 22 patients 14 (64%) had a benign course and eight (34%) behaved malignant. The malignant potential was overestimated by Weiss criteria in 23% and Aubert criteria in 27%. Wieneke and Dehner-Hill criteria showed good clinicopathological correlation; no child who had a benign course was classified as malignant. The Dehner-Hill criteria, however, classified five (23%) children as intermediate risk of which three had a clinically benign and two a CM course. CONCLUSION: The Wieneke criteria accurately predicts the clinical course in childhood ACTs and could be considered the gold standard in their pathological characterization.