Abstract
Background Central compartment lymph node dissection (CLND) is a part of the surgical management
of differentiated thyroid cancer (DTC). Therapeutic CLND is done to address clinically
significant central compartment nodes in patients with DTC, while prophylactic CLND
is performed in the presence of high-risk features in the absence of clinically significant
neck nodes. Removal of thymus—unilateral or bilateral—during CLND to achieve complete
clearance of level VI and VII lymph node stations and address thymic metastasis is
debatable.
Objective The present systematic review was conducted to summarize the evidence, delineating
the role of thymectomy during CLND in patients with DTC.
Methods Electronic databases of PubMed, Embase, and Cochrane were searched from their inception
to July 2020 using keywords—thyroid neoplasms or tumors, thyroidectomy, and thymectomy—to
identify the articles describing the role of thymectomy during CLND in DTC. A pooled
analysis of surgicopathological outcomes was performed using metaprop command in STATA
software version 16.
Result A total of three studies and 347 patients—total thyroidectomy (TT) with bilateral
thymectomy in 154, TT with unilateral thymectomy in 166, and TT alone in 27 patients
with DTC—were included in the systematic review. The pooled frequency of thymic metastasis
was a mere 2% in patients undergoing either unilateral or bilateral thymectomy. The
routine addition of thymectomy does not result in better lymph node clearance. Unilateral
and bilateral thymectomy were associated with high chances of transient hypocalcemia
(12.0% and 56.1%, respectively).
Conclusion Routine thymectomy is not warranted during CLND, considering minimal oncological
benefit and high risk of postoperative hypocalcemia.
Keywords
Head And Neck Cancer - Thyroid neoplasms - Central compartment node dissection - Thyroidectomy
- Thymectomy
