The sella in childhood hypothyroidism.

Two sellar configurations have been noted in primary childhood hypothyroidism. In the older child the sella appears unusually round and slightly enlarged, and the term "cherry" sella has been used to describe its appearance. Enlargement is due to rebound hypertrophy of the pituitary gland and is reversible with adequate, early treatment. If reversal of these changes is not accomplished one should consider the possibility of an adenoma having developed. In the young child an infant the sella appears more immature and "bowl-like". Enlargement is not a prominent feature in this age group, and indeed was difficult to detect with certainty. Both configurations, but especially the "cherry" sella of the older child, are characteristic enough to enable one to suggest the diagnosis of primary hypothyroidism from lateral skull films.