Papillary Carcinoma of the Thyroid Papillary carcinoma is the most common type of thyroid carcinoma and occurs in all age groups. Since the majority of papillary carcinomas contain neoplastic follicles, in addition to neoplastic papillae, many authors classify mixed papillary and follicular carcinomas separately from pure papillary tumours. There is, however, no accepted evidence of any difference in clinical behaviour between the various types and the term ‘papillary carcinomas’ therefore includes all tumours that contain any neoplastic papillae. These tumours are predominantly lymphangioinvasive. See later: • Papillary Microcarcinomas of the Thyroid • Intrathyroid Papillary Carcinoma • Extrathyroid Papillary Carcinoma