A 27-year-old pregnant woman was admitted to the hospital for a cesarean delivery. Diagnosed with gestational diabetes mellitus and goiter during pregnancy, with normal levels of thyroid function tests and an appropriate glycemic control. Two days after delivery, the patient developed facial swelling and pain, occipital cephalalgia, swelling and paresis of upper limbs, diplopia and dyspnea, with normal glucose blood tests. Chest radiography demonstrated superior mediastinal enlargement. Computed tomography (TC) of the brain, neck and chest was performed.