Papillary thyroid carcinoma: differential diagnosis and prognostic values of its different variants: review of the literature.

Papillary thyroid carcinoma is the most common thyroid malignancy, and has an excellent prognosis, even with cervical lymph node metastasis; however, histological variants are considered relevant, which may be associated with familial adenomatous polyposis and tumor aggressiveness. Histological features, such as vascular and/or lymphatic invasion, angiogenesis, multifocality, high cellular proliferation rate, neoplastic cell dissemination, and the histological varieties, are indicative of poor prognosis, together with associated clinical factors: age, sex, and tumor size.