Histological alterations following thyroid fine needle biopsy: a systematic review

Thyroid fine-needle biopsy (FNB) is a simple, reliable, inexpensive, and generally safe diagnostic procedure in the management of thyroid nodules. However, the trauma inflicted by the needle may lead to various degrees of histological alterations, observed in histological specimens, if thyroidectomy follows. Post-FNB histological alterations of the thyroid (PFHAT) can generally be divided into acute and chronic. Hemorrhage is the most common acute and fibrosis the most common chronic PFHAT. Some of the PFHAT causes problems in histological assessment, making diagnosis difficult, even leading to misdiagnosis. In this review, we tried to collect and summarize all reported PFHAT cases and studies, aiming to make involved physicians, cytologists, and pathologists aware of the spectrum of PFHAT and to provide information to help in differential diagnosis and to avoid misdiagnoses, which could lead to unnecessary radical surgery and/or adjuvant therapy.