De-differentiation in thyroid cancer- an increasingly appreciated concept

Abstract

Thyroid cancer is the most common endocrine malignancy. In general, they are said to be of good prognosis, still there are a few aggressive variants. Differentiated carcinomas like papillary and follicular comprise of major proportion and have a less aggressive clinical behaviour, even though some of them tend to be otherwise. De-differentiated and undifferentiated cancers are more aggressive. There has been an already existing theory that these de-differentiated cancers arise from differentiated ones by a process of stepwise molecular changes. There are already reported cases of coexistence of multiple histologies. Appreciation of dedifferentiation and identification of the genetic changes may be of help in forming improved treatment strategies, including targeted therapy. This article is to report a rare case we came across, in which three different histologies coexisted and may be pointing towards graded de-differentiation pattern. This is a further support to the stepwise de-differentiation theory.