Secondary thyroid malignancy from metastatic colon lymphoma

Primary thyroid malignancy is more frequent than secondary. This case report describes a colon lymphoma with unique thyroid metastasis. When a thyroid lesion appears in an extension study such as Positron emission tomography–computed tomography marked with 18F-2-fluoro-2-deoxy-D-glucose, it is recommended to perform an ultrasound. The correct study with ultrasound and cytology obtained through fine needle aspiration on thyroid lesion allowed to refine the diagnosis and provide the correct treatment.