Exceptional evolution of autoimmune hypothyroidism to Graves’ disease

The occurrence of Graves’ disease after an autoimmune hypothyroidism is particularly outstanding and raises questions about the mechanisms involved. Here, we report an 18-year-old patient who has been followed up for autoimmune hypothyroidism since 2009. Hormonal biological monitoring has led to gradually reduce the dose of substitution therapy and to stop it in September 2011 due to the occurrence of hyperthyroidism. The diagnosis of Graves’ disease was confirmed by the positivity of TSH-receptor antibodies. Carbimazole treatment is then undertaken. This new observation shows that this seemingly paradoxical combination is not impossible and encourages regular surveillance of these patients.