Pyramidal lobe

The pyramidal lobe of the thyroid gland is an anatomical variant defined as a conical or cylindrical projection of thyroid tissue that extends superiorly from the isthmus or adjacent part of either thyroid lobe, most commonly toward the thyroid cartilage or the hyoid bone. It represents an embryological remnant of the caudal thyroglossal duct and is considered an accessory lobe of the thyroid gland. The pyramidal lobe is present in approximately 40–60% of individuals, with a slight predominance of origin from the left side of the isthmus or left lobe, and its length and width are highly variable.