Macroscopic venous tumour thrombus in paediatric adrenocortical tumours

Macroscopic venous tumour thrombus is recognized in adult adrenocortical tumours (ACT), but its incidence, surgical implications, and prognostic impact in children remain poorly defined.

We retrospectively analysed prospectively collected registry data from 104 children and adolescents with adrenocortical carcinoma or tumours of uncertain malignant potential treated between 1997 and 2025. Patients were classified by vascular status: no invasion, microscopic invasion, macroscopic venous tumour thrombus, or unresectable disease. The study was non-randomized; treatment reflected registry recommendations and local multidisciplinary decisions.

Vascular status was no invasion in 26 patients, microscopic invasion in 54, macroscopic venous tumour thrombus in 20, and unresectable disease in 4. Macroscopic venous tumour thrombus occurred in 19.2% and involved the adrenal vein only in 6 patients, suprarenal inferior vena cava in 4, retrohepatic inferior vena cava in 7, and intracardiac extension in 3. Right-sided tumours were numerically more frequent in the macroscopic thrombus group (14 of 20, 70.0%). This subgroup was older (median 7.3 years), had larger tumours (median 11.0 cm), and showed frequent regional lymph-node involvement (95.0%), distant metastases (30.0%), neoadjuvant treatment (55.0%), and adjuvant therapy (85.0%). Complete resection was achieved in 12 of 18 surgically treated patients. Five-year overall survival was 91.0%, 73.6%, and 56.1% for patients without vascular invasion, with microscopic invasion, and with macroscopic thrombus, respectively; corresponding event-free survival was 69.0%, 58.8%, and 42.5%.

Macroscopic venous tumour thrombus identifies a high-risk subgroup, but complete resection remains achievable in selected patients and should not be equated with surgical futility.