Association of different pathologic processes of the thyroid gland in fineneedle aspiration samples

OBJECTIVE: To evaluate the possible significant association between differe nt pathologic processes of the thyroid gland. STUDY DESIGN: From a series of 10,039 fine needle aspiration biopsies of th e thyroid gland, a total of 1,330 cases were aspirated involving two or mor e palpable nodules. In 103 (1%) cases, two different pathologic processes w ere cytologically diagnosed. Statistical analysis was performed through fou r two-tailed chi (2) tests to evaluate the following events: (1) mononodula rity and multinodularity vs. neoplasms, (2) colloid goiter and neoplasms, a nd (3) all neoplasms vs. colloid goiter and lymphocytic thyroiditis. All te sts were performed using < .05 as the probability level. RESULTS: Simulataneous pathologic processes observed were: goiter. and chro nic lymphocytic thyroiditis (32), goiter and Hashimoto's thyroiditis (21), goiter and subacute granulomatous thyroiditis (8), goiter and follicular ne oplasm (9), and goiter and papillary carcinoma (14). In 12 cases we found g oiter and Hurthle cell tumor, goiter and medullary thyroid carcinoma (2), p apillar thyroid carcinoma and Hashimoto's thyroiditis (2), Graves' disease and lymphocytic thyroiditis (2), and follicular neoplasm and lymphocytic th yroiditis (1). Statistical analysis showed significant association between multinodularity and neoplasms (P < .001), while the association between goi ter and any type of neoplasm was not statistically significant. All the neo plasms taken together were associated with lymphocytic thyroiditis and goit er (P < .005). CONCLUSION: While there may be no statistically significant associations be tween the individual pathologies, it seen rs that having one pathology incr eases the risk of developing another. All the palpable nodules in the same gland should be investigated by fine needle aspiration in order to improve diagnostic sensitivity and to identify occult neoplasms.