follicular adenoma

Full Definition

A benign thyroid neoplasm characterized by a complete fibrous capsule and follicular architecture. Follicular adenomas cannot be reliably distinguished from follicular carcinoma on fine needle aspiration cytology, often requiring surgical excision for definitive diagnosis. The distinction depends on histologic examination for capsular or vascular invasion. These lesions are typically solitary and may be functioning or non-functioning.

Usage

Usage note: Emphasize that definitive diagnosis requires histologic examination, not cytology alone.

In Context

• "Follicular adenoma was confirmed on final histopathology following hemithyroidectomy." — Pathology report
• "Cytology suggesting follicular adenoma requires surgical excision for definitive diagnosis." — Clinical decision documentation