Thyroid carcinoma associated with hot nodule diagnosed by ultrasonography.

: A patient with thyroid carcinoma showing a hot nodule on radioiodine scintigraphy was examined by ultrasonography and was revealed to have occult carcinoma co-existing with adenomatous goiter. Ultrasonography should be performed to establish the diagnosis even if radioiodine scintigraphy reveals a hot nodule, as should fine-needle aspiration biopsy.