HISTOLOGIC TRENDS IN THYROID-CANCER 1969-1993 - A CLINICOPATHOLOGICALANALYSIS OF THE RELATIVE PROPORTION OF ANAPLASTIC CARCINOMA OF THE THYROID

Background: It was observed that new presentations of anaplastic carci noma of the thyroid had become infrequent in the last two decades. Met hods: All cases of thyroid cancer seen at our centre between 1969-1993 (n = 2921) were classified as papillary 49%, follicular 34%, medullar y 7.5%, anaplastic 4.7%, and other 4.8%. The total number of thyroid c ancers show a 3.5-fold rise. Results: The differentiated thyroid cance rs show a significant rising trend as against the relative proportion of anaplastic carcinoma, which shows a significant decline (P = 0.002) . Clinicopathologic data on 124 patients of anaplastic carcinoma revea led 50% patients had either long-standing goitres, previous thyroid ab normalities, or associated differentiated thyroid carcinoma on histolo gy. Conclusions: The decline in the relative proportion of anaplastic carcinoma may in part be explained by the clinicopathologic findings o r it may be attributed to histological reclassification. (C) 1996 Wile y-Liss, Inc.