Thyroid anomalies with its embryological and clinical correlation

Abstract

Objective: Thyroid gland is the first endocrine gland to start developing in the embryo. It is well-known for its developmental anomalies such as persistence of pyramidal lobe, thyroglossal duct, agenesis of isthmus, agenesis or hemiagenesis of thyroid gland, or aberrant thyroid glands. These anomalies may cause clinical functional disorders and should be kept in mind while doing surgery on the gland. Materials and Methods: A study was conducted on 37 cadavers to look for the anomalies of thyroid gland. Results: We observed six cases of agenesis of the isthmus of the thyroid gland. Four cases were of agenesis of isthmus alone, fifth case had isthmus agenesis with duplication of the thyroglossal duct remnant and a pyramidal lobe, and sixth one had isthmus agenesis with a thyroglossal duct which divides before entering the two lateral lobes. Conclusion: Such knowledge is very essential for the surgeon while performing thyroid surgeries. Understanding the surgical anatomy of the thyroid gland and its possible variations is essential for safe and effective surgery.

Keywords

• Agenesis
• isthmus
• thyroid gland
• thyroglossal duct