Surgical anatomy of the pyramidal lobe and its significance in thyroid surgery

Abstract

Aim. The purpose of this prospective study was to highlight some new findings about anatomical and morphological variations of the thyroid pyramidal lobe and to emphasise the necessity and importance of exploration of the visceral compartment of the neck and resection of this structure in primary thyroid operations. Method. We analysed 100 consecutive primary thyroid operations with additional pathological examination of the specimens. Results. A pyramidal lobe was found in 61% of the cases. The lobe of Lalouette was found more often in women (61.96%) than in men (50%) and more often (67.3%) in patients less than 50 years old than in those older than 50 (54.2%). The lobe branched off more frequently from the midline (49.18%) than from other parts of the isthmus; its length ranged from 8 to 40 mm, with a median length of 20.13 mm. In diffuse thyroid diseases, the lobes were always pathologically involved and significantly longer. Conclusion. Since the pyramidal lobe is a normal component of the thyroid gland, of varying position and size, with pathological changes in benign and malignant diseases, it should always be examined during thyroid surgery and mandatorily removed in total and subtotal thyroidectomies.