A 52-year-old woman was evaluated for an enlarging neck mass. Fine-nee
dle aspirate contained Hurthle cells and thyroidectomy revealed two se
parate thyroid morphologically similar lesions. Immunohistochemical st
udies confirmed diagnoses of separate Hurthle cell thyroid and oxyphil
parathyroid adenomas. Diagnostic pitfalls and the role of immunohisto
chemistry in diagnosis are discussed. (C) 1994 John Wiley & Sons, Inc.