Scintigraphic Evaluation of Thyroid Pyramidal Lobe

OBJECTIVE: The aim of this study is to investigate the presence of pyramidal lobe in thyroid scintigraphy and to compare the presence of pyramidal lobe in different thyroid pathologies between genders.
METHODS: Images of 866 patients (663 female, 203 male) with ages ranging from 8 to 85 were evaluated retrospectively. Presence of pyramidal lobe and its location were established in images. Patients were divided into groups in terms of gender, nodular/diffuse goiter presence, and thyroid function test results, and their rates of the presence of pyramidal lobe and whether a significant difference existed between the groups were estimated.
RESULTS: Of the 866 patients, 156 (18%) had pyramidal lobe observed in scintigraphy image. Hundred and 26 (81%) of patients observed to have pyramidal lobe were female and 30 (19%) were male. Pyramidal lob stemmed from the left lobe in 76 (48%) patients, right lobe in 61 (40%) patients, and isthmus in 19 (12%) patients. Pyramidal lobe observation rate was 18% for euthyroidism and hyperthyroidism, it was established as 12% for hypothyroidism. The rate of pyramidal lobe observation was 13% in nodular goiter patients, 43% in diffuse goiter patients, and 20% in patients whose scintigraphy showed normal thyroid glands. In the statistical evaluation, rate of pyramidal lobe in diffuse goiter patients was found to be significantly higher compared to other patients (P<0.001).
CONCLUSION: Preoperative imaging of pyramidal lobe especially in patients needing total thyroidectomy would decrease relapses that may occur later and thus facilitate the treatment and monitoring of patients.