Endocrine Abstracts

Introduction: Total thyroidectomy (TT) is a safe and effective operation. The most frequent complication after TT is hypoparathyroidism. Surgical trauma, devasculisation of parathyroid glands and inadvertent parathyroidectomy have been identified as the main causes resulting in postoperative hypocalcaemia. The objectives of this study are to investigate the incidence of intrathyroid parathyroid glands (ITPGs) in a large cohort and to clarify their histological characteristics.

Patients and methods: This is a retrospective study of two specialized centers in thyroid diseases. The medical records of patients with thyroidectomy were reviewed. Patients who underwent lobectomy or near total thyroidectomy, intentional parathyroidectomy during TT for concurrent parathyroid diseases, lymph node dissection and patients with inadequate data were excluded from the study. Patients were divided into two groups: those with (P group) and those without parathyroidectomy (non-P group). According to the location of the dissected parathyroid gland the P-group was sub-divided in ITPGs or extrathyroid parathyroid glands (ETPGs). Morphological characteristics of ITPGs were compared with the corresponding characteristics of the ETPGs in a case control way.

Results: 4500 patients with TT were included. 605 of them were excluded from the study. Inadvertent parathyroidectomy (IP) was presented in 424 cases (10.89%). Intrathyroid parathyroid glands were presented in 68 cases (1.75%). There was a trend of ITPGs being smaller in size compared to ETPGs (P=0.067). Cystic degeneration was presented in ITPGs (P=0.01). Other histological characteristics, including weight were similar in intra and extra parathyroid glands. Presence of clinical hypocalcaemia was similar in all groups.

Conclusions: The incidence of ITPGs in our cohort is 1.75%. Surgical removal of ITPGs does not increase the presence of clinical hypocalcaemia and should be consider a minor complication of TT. Patients should be informed prior to TT about the possible presence of ITPGs and, therefore, their probable accidental removal.