Endocrinological Evaluations of a Neurofibromatosis Type 1 Cohort: Is it Necessary to Evaluate Autoimmune Thyroiditis in Neurofibromatosis Type 1?

BACKGROUND: Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder in which the coexistence of autoimmune thyroiditis and thyroid gland tumours has been reported previously. AIMS: To determine the thyroid function and autoimmune thyroid diseases in neurofibromatosis type 1 patients in order to identify the possible association between neurofibromatosis type 1 and thyroid diseases. STUDY DESIGN: Case-control study. METHODS: The study includes 78 consecutive patients diagnosed with neurofibromatosis type 1 between June 2010 and June 2014 and 50 healthy controls. Baseline demographic data were generated from patient examination record forms, including age, sex, height, and weight, as well as levels of free triiodothyronine, free thyroxine, thyroid-stimulating hormone, anti-thyroid peroxidase and anti-thyroglobulin levels. RESULTS: Mean age, sex, and body mass index were similar in both groups (p>0.05). The mean levels of free triiodothyronine, free thyroxine, and thyroid-stimulating hormone were not statistically different between the neurofibromatosis type 1 and control groups. Similarly, no statistically significant difference was observed between the neurofibromatosis type 1 and control groups for anti-thyroid peroxidase and anti-thyroglobulin positivity (2.5% vs 0%, p>0.05). CONCLUSION: Screening for autoimmune thyroid disease and thyroid function seems to be unnecessary in patients with neurofibromatosis type 1.