Prognostic value of the tall cell variety of papillary cancer of the thyroid.

We analyse a new variety of papillary carcinoma of the thyroid, known as the tall cell variant. The lesion is characterized by a papillary cancer (PCT) in which more than 30% of the tumour is made up of a population of tall columnar cells over twice as tall as their width. Of a population of 158 differentiated thyroid carcinomas we found five cases of this rare variant. We studied their clinico-pathological features, the importance of an early diagnosis and their prognostic implications. The data were compared with those of Well-Differentiated or Classical PCT (WDPC), the most important features of which were: (a) later age of appearance; (b) greater predilection for males; (c) greater frequency of extrathyroid tumor extensions; (d) greater frequency of recurrences; and (e) a shorter survival or disease-free interval. The prognostic importance involved in recognizing this variant is based on the need to give patients a more aggressive treatment and more exhaustive follow-up.