Pyramidal Lobe in Total Thyroidectomy: A Prospective Study of 445 Patients With Papillary Thyroid Carcinoma.

OBJECTIVES

The pyramidal lobe (PL), a normal yet highly variable anatomical structure of the thyroid gland. Current literature suggests that 10% to 30% of patients undergoing total thyroidectomy (TT) exhibit residual PL tissue, which may compromise the completeness of cancer resection, hinder postoperative radioiodine therapy, and impact serum thyroglobulin levels. Notably, major guidelines from the American Thyroid Association, European Society for Medical Oncology, National Comprehensive Cancer Network lack specific recommendations regarding PL management. This study evaluates its role and necessity in TT, particularly in papillary thyroid carcinoma (PTC).

METHODS

A retrospective review of prospectively maintained data from 445 PTC patients who underwent TT at our institution (January 2022-April 2024) was conducted. Intraoperative PL localization was recorded, and specimens were assessed for PL presence and histology. Surgical complications, thyroid function and radioiodine-131 treatment were monitored during follow-up.

RESULTS

Pathology confirmed PL in 242 of 445 patients (54.04%), with intraoperative identification accuracy at 95.30% (242/254). The remaining 12 resected specimens exclusively comprised muscular tissue. Occult PTC was detected in 21 PLs (4.72% of the total cohort; 8.68% of those with PL), all part of multifocal tumors. PL-associated PTC was an independent risk factor for prelaryngeal lymph node metastasis [OR (95% CI): 3.332 (1.230-9.025), P = .018]. PL removal facilitated prelaryngeal lymph node dissection without increasing surgical complications.

CONCLUSIONS

PL resection in TT removes occult PTC and optimizes prelaryngeal lymph node dissection without increasing surgical complications. This highlights the value of routinely excising the pyramidal lobe during total thyroidectomy to ensure thorough removal of residual cancer.