Needle track dissemination of follicular thyroid carcinoma following fine-needle aspiration biopsy: report of a case.

Few reports have been concerned with the risk of needle track dissemination of tumor cells following fine-needle aspiration biopsy, especially for follicular thyroid nodules. A 61-year-old woman who underwent fine-needle aspiration biopsy and surgery 5 years previously for follicular thyroid adenoma presented with nodules that had developed in the sternocleidomastoid and omohyoid muscles of the anterior neck. These nodules were located along a line from the skin to the thyroid that coincided with the needle track of the previous biopsy. Following surgical resection, histological diagnosis determined the nodules to be follicular carcinoma. The clinical course and linear arrangement of the lesions were highly suggestive of needle track dissemination of tumor cells following fine-needle aspiration biopsy. Although fine-needle aspiration biopsy is a useful tool for the diagnosis of thyroid nodules, it is important to consider the risk of tumor cell dissemination.