Thyroid Gland Follicular Adenoma with Papillary Architecture

**Semantic type:** Neoplastic Process

**Definition:** A benign, encapsulated thyroid gland neoplasm characterized by the presence of large follicles with intrafollicular papillary architecture. The cells lining the papillae are usually columnar. It is usually a cystic neoplasm and lacks nuclear atypia and capsular invasion. Psammoma bodies are not present. Activating TSHR mutations have been described in the majority of cases. In a small number of cases GNAS mutations have been identified.

**Synonyms:** - Thyroid Gland Follicular Adenoma with Papillary Hyperplasia