RESUMO
Thyroid abnormalities are found nearly 70% cases receiving sunitinib therapy. Mostly, patients suffer transient hypothyroidism rarely presents with overt acute symptoms requiring levothyroxine replacement. Onset is variable in published literature. We report a case of metastatic gastrointestinal stromal tumor receiving sunitinib with normal baseline thyroid function. The patient developed symptoms of acute severe hypothyroidism with high thyroid stimulating hormone level on the 4th week of therapy. The patient responded with oral levothyroxine. clinical and biochemical parameter resolved rapidly. Patient receiving sunitinib warns baseline and subsequent surveillance of thyroid function (both clinical and biochemical). This rare dreadful condition reverts promptly with thyroxine replacement.