Papillary carcinoma thyroid – Histological subtypes and clinical significance

Papillary carcinoma thyroid is a very common malignancy of the thyroid having a very good overall prognosis. Among the subtypes of this tumor certain histological subtypes identified are more aggressive than the ones with classic histology. The purpose of this review is to stratify the prognosis concerning papillary thyroid carcinoma patients with different histopathological patterns, their features of identification, and molecular differences. This is a narrative review of various published articles including meta-analysis results. This does not contain any studies with human participants by the author. A general outline of each subtype with histologic descriptions, relevant differential diagnosis, immunohistochemical as well as ancillary studies is discussed in this article. The rarity of the aggressive subtypes of papillary carcinoma and poor understanding of tumor biology can lead to inadequate treatment, and hence, the correct diagnosis is very important, and equally important is the awareness of these entities among the treating physicians.