[Basedow's disease in a female patient with breast cancer metastasizing to the thyroid].

A case is presented of a woman with a breast cancer who developed Basedow's disease several months after the diagnosis of the cancer. In spite of the antithyrotoxic treatment the Basedow's symptoms persisted till the end of life. The case is compared with other similar cases in which the combination of Basedow's disease with a metastatic tumour of the thyroid gland is not described. Probably the tumour invasion of the thyroid gland triggers the appearance of various clinical syndromes of hyperthyroidism including the full classical picture of Basedow's disease as is the case in the reported patient. The intimate etiopathogenetic mechanisms of these thyrotoxic syndromes are not yet clear.