ESPE Abstracts

Background: in general population Hurthle cell cancer (HCC) accounts for 3-7% of all differentiated thyroid cancers (TC) with a more aggressive course, while its relative prevalence and behavior in childhood is uncertain due to the lack of specific literature reviews.

Objective: to describe the largest pediatric HCC cohort to date reported and to estimate its relative prevalence among TC variants in childhood.

Methods: study population included 5 patients <19 years, who were diagnosed with HCC during the period 2000-2018 in our Departments. Histologic diagnosis of HCC was based on the finding of at least 75% of Hurthle cells at post-surgical analysis. HCC course was retrospectively reconstructed with data recorded at diagnosis, at surgical resection and during a follow-up period ranging from 6.5 to 15 years. Patients' assessment included: clinical findings, thyroid function and autoimmunity tests, neck and chest imaging (ultrasound and computed tomography scan), cytologic and histologic analyses of the tumor.

Results: HCC occurred with a relative prevalence of 5.8% (5 of 86 young patients affected by TC, diagnosed in the same period and institutions), at a median chronological age of 12.5 years. All patients were biochemically euthyroid at HCC diagnosis and underwent both total thyroidectomy with central neck dissection and radioiodine therapy, with subsequent L-T4 thyroidal suppression. Low or intermediate risk level was observed at diagnosis, since none of our patients exhibited extensive lateral neck disease or distant metastases and all of them showed a persistent clinical, biochemical and imaging remission over time. Antecedents of other diseases were recorded in 3 patients (Hashimoto's thyroiditis, Neurofibromatosis type 1 and osteosarcoma respectively).

Conclusions: 1) in childhood the relative prevalence of HCC among TC histotypes is 5.8%, that is close to the one reported from literature both in general population (3-5.7%) and in young patients (2-7%); 2) HCC may develop even very early, at an age of 7 years; 3) in pediatric age HCC does not seem to have a more aggressive behavior than other TC histotypes; 4) antecedents of other diseases are not infrequent in the history of children with HCC.