Anomalous development of thyroid gland; a cadaveric study in coastal population of Andhra Pradesh

Abstract

Introduction: Thyroid gland is a butterfly shaped richly vascular, brownish-red endocrine organ, located at the lower part of the neck opposite to the fifth, sixth and seventh cervical and the first thoracic vertebrae. On account of developmental abnormalities thyroid gland shows various morphological anomalies like absence of isthmus, ectopic position, and absence of any one of the lateral lobes. Aims: The present study is aimed at documentation of morphological abnormalities and their incidences of thyroid gland, which is useful for the surgeons to plan for proper surgical procedures in thyroid disease. Materials and Methods: The present study was conducted in 50 cadavers (39 male & 11 female) in coastal region of Andhra Pradesh. Results: There is variable lobular pattern in 21 (42%) cadavers. Out of these, isthmus was absent in 8 (20.5%) male, and 3 (27.3%) female cadavers. Relation of tracheal rings to the isthmus was noted. Pyramidal lobe was present in 17 (43.5%) male and 2 female (18.1%) cadavers. Pyramidal lobe is frequently arising from the Isthmus. Levator glandulae thyroideae (LGT) was present in 16 (41%) male and 2 (18.1%) female cadavers. The average height and thickness of right lobe is 4.3cm and 1.15 cm and left lobe is 4.2cm and 1.15cm. Conclusion: As developmental abnormalities of the thyroid gland are common, it is essential to know their variations and incidences for successful thyroid surgeries. Keywords: Thyroid gland, Pyramidal lobe, Isthmus, Levator glandulae thyroideae.