Double pyramidal lobe of the thyroid gland: report of two consecutive cases with surgical and oncologic implications

The pyramidal lobe (PL) of the thyroid gland is a common embryological remnant; however, the presence of double PLs is an exceptionally rare anatomical variation. Failure to recognize this anomaly may result in incomplete thyroidectomy, particularly in patients with thyroid malignancy. We report two consecutive cases of double PL identified intraoperatively within a 2-day interval at a single center. The index case was a 51-year-old woman operated on for a suspicious thyroid nodule, with final pathology revealing classic variant papillary thyroid carcinoma (2.3 cm) with central lymph node metastases (pT2N1a, AJCC 8th edition). Two distinct PLs arising from the isthmus were identified and completely excised. Two days later, a 55-year-old man with multinodular goiter and a history of asthma underwent thyroidectomy, during which an identical double PL configuration was detected and removed. In both cases, preoperative ultrasonography failed to identify the PLs. The occurrence of two consecutive cases suggests that double PL may be underrecognized rather than truly exceptional. Systematic exploration of the prelaryngeal region is essential to ensure complete thyroidectomy and optimal oncologic outcomes.