Abstract
Background : Parathyroid carcinoma is a rare neoplasm accounting for only 1-3% of primary hyperparathyroidism cases. We report the cytological features of parathyroid carcinoma with anaplastic transformation.
Case : A 70-year-old man seen for a nodular right-lung lesion found in chest X-ray screening was found in computed tomography (CT) to have a cervical tumor posterior to the lower right thyroid gland. Blood calcium and parathyroid hormone (PTH) levels were elevated. Suspected parathyroid carcinoma with pulmonary metastasis necessitated excision with right thyroid lobectomy. Smear cytology showed two types of tumor cells-differentiated with round nuclei and anaplastic with large pleomorphic nuclei. Transition was noted from differentiated to anaplastic tumor cells. Postoperative blood calcium and PTH levels returned to normal and the pulmonary lesion shrank markedly without further treatment.
Conclusion : Gene analysis showed that anaplastic tumor cells carried a p53 gene point mutation, while remaining differentiated carcinoma cells had the wild-type p53 gene. These findings suggest that p53 gene mutation is associated with anaplastic parathyroid carcinoma transformation.
