Abstract
A case of primary hyperparathyrodism (PHP) associted with advanced thyroid cancer in a 67-year-old woman is reported. In this case the differential diagnosis before operation was very difficult. It is not rare that the patient with PHP has a thyroid cancer, however, the thyroid cancer is commonly occult or small, and rarely large and advanced seen in this case. In the operative treatment of PHP, the thyroid gland must be explored carefully. If a thyroid cancer accidentally found is smal, lobectomy of the thyroid gland may be a proper treatment. However if it is advanced, subtotal thryoidectomy and modified neck dissection or more extensive operation must be chosen.
