Histologic analysis and comparison of techniques in fine needle aspiration-induced alterations in thyroid

Objective: To assess histologic alterations following fine needle aspira tion (FNA) of the thyroid and differentiate these from omi nous lesions, such as papillary carcinoma thyroid, as well as assess and compare the degree of tissue trauma from the techniques: needle only vs. needle with syringe, size of nee dle and number of aspirations. Study Design: Thyroidectomy specimens of 100 cases with prior FNA biopsy were selected. The changes called "worrisome histologic alteration following fine nee dle aspiration of the thyroid" (WHAFFT) were studied. Number of FNAs, needle size and technique were tabulat ed for 73 of 100 cases. Results: Worrisome changes were confined to areas near the needle tract and hence could be differentiated from ominous lesions. Control cases did not show WHAFFT lesions. Non-aspiration FNA cytology (FNAC) technique results in fewer, less fre quent WHAFFT changes. The increasing number of FNAs leads to statistically significant increase in infarction, necro sis and vascular changes. A gradation in the WHAFFT changes, directly proportional to the increasing diameter of the needle, was observed. Conclusion: The pathologist should be aware of WHAFFT to avoid mis interpretation. The technique of non-aspiration FNAC is significantly less traumatic. An inarase in FNAs or size of needle results in more severe WHAFFT changes.