Non-endemic goitrous cretinism.

Enlargement of the thyroid gland is an unusual finding in cretins outside endemic goitrous areas. Wilkins, Clayton and Bertirong (1954), reviewing published cases of non-endemic goitrous cretinism, collected reports of 32 cases and described a further four cases of their own. Other cases have been reported by Rienhoff (1940) and Smallpeice (1949). The hypothyroidism in these cases is of variable degree and the thyroid enlargement may appear at any time from infancy to adult life. Early administration of thyroid extract in adequate dosage causes the enlarged thyroid to return to normal size unless irreversible pathological changes have taken place in the gland. Subsequent withdrawal of the drug or reduction in dosage results in reappearance of the goitre. In glands which have been removed the histological changes are broadly those of hyperplasia leading to involution and fibrosis. Radioactive iodine studies have so far been reported in 26 cases (Hamilton, Soley, Reilly and Eichorn, 1943; Lerman, Jones and Calkins, 1946; Stanbury and Hedge, 1950; Stanbury, 1951; Hubble, 1953a; McGirr and Hutchison, 1953; Wilkins et al., 1954) and have shown that the enlarged thyroid glands have an unusual avidity for iodine, unlike cases of non-goitrous sporadic cretinism in which there is little or no uptake of radioactive iodine. From these facts the aetiology of non-endemic goitrous cretinism would appear to be a complete or partial failure of production of thyroid hormone with, presumably, an excessive secretion of pituitary thyrotropic hormone resulting in hyperplasia of the thyroid gland. An identical condition may also be produced by the action of goitrogenic agents and is known to occur in the newborn infant following administration of thiouracil to the mother during pregnancy (Elphinstone, 1953). The high incidence of the disease in siblings suggests that the defect is gMentically determined, possibly by a recessive mode of inheritance. The rarity of this type of cretinism and the value of radioactive iodine studies in elucidating the exact