[Unusual isotope scanning aspects of hot thyroid nodules: diagnostic problems].

The classical picture of development of the "hot" nodule, which takes into account at the same time fixing or non-fixing nature of healthy perinodular tissue and the clinical condition of the patient fails to explain certain biological and scintigraphic findings. The authors discuss problems related to scintigraphy which they encounter in the course of the examination. In 174 stimulation tests carried out, 12 resulted in hypofixation of the isotope in the nodule, scintigraphy being carried out in three patients using 99-mTcO4 spontaneous reactivation of healthy tissue was seen in 5 patients. In the light of the cases reported, it would appear that the scintigraphic picture of the "hot" nodule is more in favor of a duality between the latter and healthy tissue with respect to iodine than of a hypersensitivity to TSH. In the 12 inhibition studies carried out, 3 showed the persistence of a contralateral shadow. Finally, on five occasions histological examination of the operative specimen showed the presence of neoplastic change, in two cases within the "hot/ nodule.