“Hook Effect” in Calcitonin Immunoradiometric Assay in Patients with Metastatic Medullary Thyroid Carcinoma: Case Report and Review of the Literature

Abstract

To our knowledge, this is the first reported case of a phenomenon such as the hook effect in a calcitonin immunoradiometric assay in patients with MTC. Being aware of this phenomenon is important, because a low calcitonin result could give false reassurance to both the patient and the clinician and could dramatically change the prognosis of the patient.