ABSTRACT
Congenital goiter associated with hypothyroidism is a genetically determined condition in which there is a biochemical abnormality in one or more of the steps in the synthesis of thyroid hormone. The metabolic block in hormone formation leads to an increase in secretion of Thyroid-stimulating hormone that in turn causes hypertrophy of the epithelial elements of the glandular follicules, increased vascularity of the gland, and diminished colloid. Although patients with dyshormonogenetic goiter are classified into several categories according to the types of biochemical defects, the clinical picture in most patients is almost identical: goiter associated with hypothyroidism or with borderline thyroid hypofunction. An enlarged thyroid gland is usually present at birth but in the absence of adequate thyroid substitutive therapy with L-thyroxine, goiter commonly becomes more evident and larger thereafter. Cellular atypias are a common feature in dyshormonogenetic goiters.
