Endocrine Abstracts

Background: The thyroid pyramidal lobe (TPL) represents a normal anatomical variation of the thyroid gland. Intraoperative TPL identification is of paramount significance, taking into account that the remnant TPL leads to higher thyroglobulin, could contain thyroid carcinoma foci and lead to recurrence.

Methods: We conducted a prospective single-center, single-operator study to identify TPL in 500 consecutive patients undergoing thyroid ultrasound for any indication. We extended the standard technique to actively search for TPL. The findings reported were presence and site of the TPL (right vs left), presence of incidentally discovered nodules in TPL and thyroglossal duct cysts (TGDC). We excluded patients who underwent thyroid surgery or radioiodine therapy.

Results: Of the 500 consecutive patients, TPL was identified in 113 (22.6%), 4 had TGDC, 2 had hemiagenesis of the left thyroid lobe. Fourty-nine patients (43.4%) presented with left-sided TPL, 64 (56.6%) with right-sided. In 4 patients (3.5%), we identified incidental asymptomatic nodular lesions within TPL.

Conclsions: We suggest to routinely screen for thyroglossal duct remnants (TPL or TGDC) during thyroid ultrasound. This may reduce the rate of postoperative remnant TPL, obtain lower postoperative thyroglobulin levels and potentially lead to less frequent radioiodine therapy indication. Incidental discovery of thyroid nodules within TPL could also play important role in patient management. We observed a higher prevalence of the right-sided TPL in our study, which differs from previous reports stating more frequently left-sided TPL.