Key-Role of TSH Deficiency in Disclosing Craniopharyngioma Diagnosis in a Short Girl with Hashimoto’s Thyroiditis

Background: Hashimoto’s thyroiditis (HT) in childhood may present with either euthyroidism (52.1% of cases), or primary overt hypothyroidism (22.2%), subclinical hypothyroidism (19.2%), overt hyperthyroidism (3.5%), or subclinical hyperthyroidism (3%). In a large series of 608 children and adolescents with presenting HT, we found in no cases a biochemical picture with low free thyroxine (FT4) and normal or low-normal TSH serum levels, i.e. a thyroid pattern that is consistent with central hypothyroidism (CH), but is not compatible with HT. Therefore, the finding of such a biochemical pattern in a child with HTshould direct work-up towards seeking an associated central cause of hypothyroidism. Aim: The aim of the present case report is to reinforce the above view. Case report: In a short girl with celiac disease and HT, the suspect of an associated pituitary lesion was suggested, despite the lack of neuro-ophthalmic symptoms, by the finding of a thyroid function pattern that was not compatible with HT (low FT4 with normal TSH). This case report reinforces the view that the finding of a normal TSH in presence of a low FT4 should always alert pediatricians and raise the suspect of central hypothyroidism, even when a primary thyroid disease has been already identified. In this case TSH deficiency played a critical role in disclosing diagnosis of craniopharyngioma (CP). Conclusions: Among the endocrinological manifestations of CP, TSH deficiency is observed in only 25% of children, whereas GH deficiency (100% of cases) and ACTH deficiency (68%) are distinctly more frequent. In this case report TSH deficiency was present and played a critical role in disclosing diagnosis of CP. If it had been absent, it might be hypothesized that diagnosis of CP would have been furtherly delayed.