Nodular hyperplasia in treated congenital goitrous hypothyroidism.

Two patients with congenital goitrous hypothyroidism, treated since birth, are described. Each developed progressive nodular thyroid enlargement in adolescence, possibly related to ongoing thyroid stimulation due to slight and transient elevations of thyroid stimulating hormone (TSH) levels. The incidence and degree of persistent thyroid enlargement in these patients has not been well documented. If present in a significant number of patients despite appropriate L-thyroxine replacement, our therapeutic aims in congenital goitrous hypothyroidism may need to be modified to achieve TSH suppression, rather than normalization.