PRIMARY CARCINOID TUMOR OF THE THYROID GLAND

The concept of carcinoid was introduced by Oberndorfer in 1907, for small tumors arising in the small intestines. Recently, however, cases of carcinoid tumors arising outside the gastrointestinal tract (thymus, ovary, etc.) have been increasingly reported. We encountered a tumor that was diagnosed as carcinoid tumor of the thyroid after thorough examination by optical and electron microscopy and immunohistochemical techniques. The patient was a 76-year-old woman with a tumor mass on the anterior aspect of the neck and symptoms that resembled those of the carcinoid syndrome: flushing, dizziness and diarrhea. Both thyroid and parathyroid were functioning normally and blood calcitonin levels were within the normal range. Left hemithyroidectomy was carried out on June 15, 1985. The postoperative course was uneventful and various symptoms were attenuated. Our survey of the literature disclosed that no primary carcinoid tumor arising in the thyroid has been reported previously, and that not only the definition of carcinoid tumors arising in the thyroid but also the classification of so-called C-cell origin tumors of the thyroid remain unclear. The case is therefore reported with some discussion.