Tumour seeding after fine-needle aspiration and core biopsy of the head and neck--a systematic review.

Although fine-needle aspiration cytology (FNAC) and core needle biopsy are essential diagnostic investigations of lumps in the head and neck, seeding along the needle track has long been a concern, and various factors have been implicated. We therefore searched the Medline database for relevant English language papers published between 1970 and 2014, excluding those on the thyroid and parathyroid, and systematically reviewed them to assess the risk. In the 610 articles reviewed we found only 7 reports of seeding (5 after FNAC and 2 after core needle biopsy).