[Redifferentiation therapy with rosiglitazone in a case of differentiated thyroid cancer with pulmonary metastases and absence of radioiodine uptake].

Treatment with radioiodine (RDI) has been shown to be an effective option in patients with differentiated thyroid cancer with recurrent or metastatic disease. However, in spite of having elevated levels of thyroglobulin in blood, in some of these patients, the whole body scan does not detect radioiodine uptake due to loss of differentiation of the neoplastic cells, thus leading to loss of efficacy of the treatment. That is why drugs with potential differentiating properties, like rosiglitazone or retinoids, are being studied. The aim of these drugs is to improve RDI uptake by the tumor cells. In this work, we have described the case of a patient in whom uptake of RDI by the pulmonary metastases, with subsequent decrease of their size, was achieved after treatment with rosiglitazone (8 mg/day for 2 months) as redifferentiation therapy.