Benign hepatic cyst mimicking thyroid carcinoma metastasis

Introduction: The follow-up of differentiated thyroid carcinoma (DTC) for detecting persistent or recurrent disease is based on iodine whole body scan (WBS), the evaluation of the tumor marker thyroglobulin (Tg), the anti-thyroglobulin antibody (anti-Tg) and neck ultrasonography (US). Well known false-positive causes of WBS include inflammatory processes, some non-thyroid tumors, kidney or even sebaceous cysts. Methods: We reported a case of false-positive WBS, after therapeutic dose of (I-131) Nal. Results: We enphasize the importance of recognizing benign liver cysts mimicking DTC metastasis. Conclusions: False-positive and negative results may occur with WBS and must be recognized to avoid mismanagement. Arq Bras Endocrinol Metab. 2009;53(6):777-82