[Thyroid biopsy in the auto-immune thyroid diseases]

There are three types of thyroid biopsy, fine needle biopsy, large needle biopsy and open biopsy. The aim of thyroid biopsy is not the diagnosis of auto-immune thyroid diseases itself, but the differential diagnosis of coexisting nodular goiter. Though fine needle aspiration biopsy cytology(FNABC) is a safe and valuable method, there is a limit. Large needle biopsy has small part for thyroid field. In case of malignant lymphoma or anaplastic carcinoma, the open biopsy is recommended. By using ultrasonic guide technique, the accuracy of ABC has come to high. Immunohistochemical method or molecular biological technique are now available.