Discordance between cytologic results in multiple thyroid nodules within the same patient.

Objective: To examine the frequency of discordant cytologic results between multiple thyroid nodules biopsied in the same patient.

Study Design: In a retrospective chart review of 441 consecutive patients, 326 (73.9%) had 2 or more nodules with colloid and/or thyroid cells recovered. Cytology was classified as (A) colloid only, (B) benign colloid nodule with or without degeneration, (C) Hashimoto's, or (D) follicular or Hürthle cell neoplasm, hyperplasia or suspicious for malignancy. Discordance was defined as having at least 2 different categories in the same patient. Twenty-four predetermined factors were analyzed, including demographics, laboratory values and ultrasound characteristics.

Results: The results, by category, were A, 164 (18.4%); B, 575 (64.6%); C, 131 (14.7%); and D, 20 (2.2%). Overall, 126 of 326 (38.7%) patients had at least 1 discordant grouping between their nodules. Of 326 patients, 165 had 2, 94 had 3, 48 had 4, 14 had 5, and 5 had 6 nodules biopsied, of which 48 (29.1%), 39 (41.5%), 29 (60.4%), 8 (57.1%) and 2 (40.0%), respectively, showed diagnostic discordances (p = 0.0007).

Conclusion: The high rate (38.7%) of discordance between biopsies of multiple nodules in the same patient support a recommendation to biopsy all nodules that otherwise meet criteria for biopsy, as opposed to only the largest one.