Clinical features of differentiated thyroid carcinoma in children and adolescents from a sub-Himalayan iodine-deficient endemic zone.

Northern India is an identified sub-Himalayan iodine-deficient endemic zone. We retrospectively analysed the case files of children with differentiated thyroid carcinoma from this endemic zone and attempted to define the disease in terms of its presentation, clinical course and outcome of radioiodine therapy. Between 1967 and June 2000, 1135 patients with thyroid cancer were treated in our centre and 80 (7%) were less than 20 years of age. There were 45 females and 35 males. Histologically, 85% of patients had papillary carcinoma and the rest follicular carcinoma. Cervical lymph node involvement was seen in 66% of patients, and distant metastasis, mainly pulmonary, in 29%. In children less than 10 years of age, 75% of patients had distant metastasis at the time of presentation. The post-surgery 48 h radioiodine neck uptake was 12.2+/-9.6%. Ninety-six per cent of the residual thyroid, 90% of nodal metastases and 57% of pulmonary metastases were ablated. Although nine patients had nodal recurrence between surgery and radioiodine treatment, no recurrence was observed thereafter, and three disease-related deaths (all in children less than 10 years of age) were seen in the mean follow-up of 6 years. We conclude that, except for the relatively higher incidence of follicular thyroid cancer and the higher mortality in the less than 10 year age group, the course and outcome of differentiated thyroid carcinoma in children from iodine-deficient areas is no different from that in children in iodine-sufficient areas.