Thyroid neoplasms: incidental findings on extent of disease evaluation CT for other pediatric malignancies

Purpose We performed a retrospective analysis to evaluate the risk of thyroid cancer in incidental thyroid nodules (ITNs) discovered on CT in patients with a history of pediatric cancer. Methods With IRB approval we reviewed the records of pediatric oncology patients age ≤ 21y with newly detected thyroid nodules on surveillance CT of the neck, chest, chest/abdomen/pelvis, or PET/CT performed between April 2008 and March 2015. Patients with < 6 months of follow-up after incidental findings, a history of primary thyroid malignancy, or incomplete records were excluded. Results The final cohort (N = 68) included 35 females and 33 males (mean age 16.0 ± 4.3[SD] years) with a mean follow-up time of 3.7 ± 1.9[SD] years after CT detection of ITN(s). Twenty patients (29.4%) received a follow-up thyroid ultrasound, eleven (16.2%) of whom underwent fine needle aspiration (FNA) for cytopathologic diagnosis. Among these, six (8.8%) underwent thyroid resection, with final pathology demonstrating papillary carcinoma in five (7.4%) and benign pathology in one. Conclusions Despite the low incidence of thyroid nodules and low risk of thyroid malignancy in the general pediatric population, we found a significant rate of malignancy in CT-detected ITNs in our pediatric oncology patients, and recommend ultrasound and FNA of these nodules in this high-risk population. Level of evidence Level IV, retrospective study with no comparison group.