Imprint cytology of parathyroid tissue in relation to other tissues of theneck and mediastinum

OBJECTIVE: To retest the hypothesis that imprint cytology may be used to re liably diagnose parathyroid tissue and, if so, to ascertain whether accurac y in this technique may be easily attained. STUDY DESIGN: Imprint preparations from 15 parathyroid, 10 thyroid, 8 lymph oreticular and 2 adipose tissue specimens were assessed blindly by two path ologists, one of whom (pathologist B) had only limited experience with endo crine tissue implicit cytology. RESULTS: Both assessors consistently distinguished parathyroid and thyroid preparations from lymphoreticular and adipose tissue preparations. While th ere was occasional difficulty in distinguishing between parathyroid and thy roid preparations, this was usually attributable to the scanty nature of th e preparations. No single cytologic feature allowed a distinction between p arathyroid and thyroid tissue. However, by considering several relatively d iagnostic features collectively, pathologist B showed an increase in specif icity and sensitivity rates for distinguishing parathyroid from thyroid imp rints from 82% to 100% and 57% to 83%, respectively. CONCLUSION: The high accuracy rates and rapid learning curve shown by impri nt cytology in distinguishing between different neck ou mediastinal tissue types, together with ifs time- and cost-cutting potential, support a role f or the technique in the intraoperative diagnosis of parathyroid tissue.