Intraoperative cytology increases the diagnostic accuracy of frozen sections for the confirmation of various tissues in the parathyroid region.

The identification of parathyroid gland tissue and its distinction from adjacent structures such as thyroid gland, lymphoid, fibroadipose, and, rarely, thymic tissues on frozen section (FS) may be challenging owing to freezing artifact. Intraoperative cytology (IC) provides valuable complementary morphologic details. We evaluated 72 specimens with IC alone (group 1), followed by interpretation with FS to reach a final interpretation using IC and FS together (group 2). An additional 105 specimens were evaluated by FS alone (group 3). Permanent section diagnosis was used as the "gold standard." Sensitivity and specificity were 100% for group 2, compared with lower values for group 1 (98% and 100%, respectively) and group 3 (94% and 94%, respectively). IC is a valuable adjunct to FS during intraoperative consultation for evaluation of tissue in a parathyroid location.