Spindle and giant cell metaplasia in papillary carcinoma of the thyroid

The preceding discussion serves to re-emphasize that metaplasia to a highly lethal form of thyroid cancer can occur in the usually indolent papillary thyroid cancer. When this happens, these patients usually have the ominous signs previously elucidated. There is recent rapid growth in the thyroid or neck nodes, a large (over 5 cm.) tumor, and recurrent laryngeal nerve palsy. However, these signs are not always present.Furthermore, metaplasia may not be manifest in the first material examined histologically. There may be a long interval from the initial treatment to the appearance of large areas of metaplasia (twelve and ten years in two of these cases). Metaplasia may be present in either or both the primary tumor, cervical, or other metastases. Its absence in the primary lesion does not preclude its appearance in subsequent metastases. This was demonstrated in two patients in this review. There was metaplasia in a submental node in one (case IV) and an axillary node in the other (case V) with no evidence of metaplasia in the primary lesion in either. Once spindle or giant cell metaplasia is evident in large amounts, the prognosis is grave; the average time until death is five months.