title: Twenty-one-gauge needles provide more cellular samples than twenty-five-gauge needles in fine-needle aspiration biopsy of the thyroid but may not provide increased diagnostic accuracy.
abstract: The technique of fine-needle aspiration (FNA) biopsy of the thyroid is important to evaluate malignancy in thyroid nodules. Eighty-five percent of thyroid FNA procedures lead to sufficient cellular material for diagnosis. With more cells aspirated, the chance of sufficiency for diagnosis increases. Large-bore needles lead to more cellular material being aspirated but bloodier specimens that may interfere with cytologic interpretation. Small-bore needles may result in too few cells for diagnosis. We conducted a randomized prospective study contrasting 21-gauge and 25-gauge needles in the evaluation of 50 consecutively enrolled nodules at our institution. In our investigation, 21-gauge needles more frequently provided superior biopsy specimens (50%) than did 25-gauge needles (18%). In the remaining specimens (32%), the 21-gauge and 25-gauge needles provided similar cellular material. The rate of sufficient samples was the same. We conclude that use of 21-gauge needles results in more cellular specimens but may not result in increased diagnostic accuracy.
authors.affiliation: Department of Medicine, Boston University School of Medicine, Massachusetts 02118, USA.
authors.forename: V
authors.initials: V
authors.lastname: Tangpricha
authors.forename: B J
authors.initials: BJ
authors.lastname: Chen
authors.forename: N C
authors.initials: NC
authors.lastname: Swan
authors.forename: A T
authors.initials: AT
authors.lastname: Sweeney
authors.forename: A
authors.initials: A
authors.lastname: de las Morenas
authors.forename: J D
authors.initials: JD
authors.lastname: Safer
mesh_terms: D001707:Biopsy, Needle / Q000295:instrumentation*; D002498:Centrifugation / Q000379:methods; D006461:Hemolysis; D006801:Humans; D011446:Prospective Studies; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000473:pathology; D016606:Thyroid Nodule / Q000175:diagnosis / Q000473:pathology*