Incidence of pyramidal thyroid lobe in the university college hospital Ibadan

The pyramidal lobe of the thyroid gland is derived from remnant of the thyroglossal duct. Its presence may be missed clinically; however radiologic and intra-operative findings reveal its presence in up to 50% of cases. The incidence of pyramidal lobe is however not clearly known in Sub-Saharan Africa, particularly in Nigeria. Our aim is to determine the incidence and histological variation of pyramidal lobe of the thyroid gland among surgical patients who underwent thyroid surgery in the University College Hospital, Ibadan.

Consecutive surgical patients that underwent total thyroidectomy in the Endocrine Surgery Division, Department of Surgery, University College Hospital, Ibadan between April 2013 and April 2017 were recruited irrespective of age, sex and clinical diagnosis. The presence, anatomy and subsequent histological diagnosis of the pyramidal lobe were noted.

One hundred sixty thyroid surgeries were done. Pyramidal lobe was found in 70 patients (44.0%). The presence of the pyramidal lobe was most often associated with multinodular goitres 42 (61.8%) and least found in thyroids with malignant tumours 3 (4.4%). The pyramidal lobe originated commonly from the midline (50.0%) and least from the right (10.3%). The length of the pyramidal lobes ranged from 8 to 80 mm (average 50 mm) in males and 5 to 54 mm (average 42 mm) in females.

The presence of a pyramidal lobe is not uncommon in people of southwestern Nigeria with its morphologic and histologic profile akin to what obtains in other geographical locations of the world.