The utility of intra-operative frozen section for the evaluation of microscopic extrathyroidal extension in papillary thyroid carcinoma.
OBJECTIVE
This study was designed to evaluate the usefulness of intra-operative frozen section for the evaluation of microscopic extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC).


METHODS
Retrospective cohort study.


METHODS
Dong-A University Medical Center, Busan, Korea.


METHODS
Three hundred and sixty-four patients who underwent thyroid surgery from January 2000 to December 2010 with PTC confined to one unilateral lobe as diagnosed using preoperative ultrasonography were enrolled.


METHODS
The patients who had microscopic ETE on frozen section were classified into "group A," and those who did not have microscopic ETE on frozen section were classified into "group B." Clinicopathologic factors including age, gender, size of the tumour, extent of operation, ETE, multifocality, bilaterality, lymph node metastasis and recurrence were compared between the two groups.


RESULTS
Of the 364 patients enrolled, ETE was confirmed in 100 patients (group A, 27.5%) on frozen biopsy. The nodule size in group A (0.94±0.87 cm) was larger than that in group B (0.86±0.79 cm) (P=.042). In group A, 15 patients (15%) showed multifocality and 11 patients (14.47%) showed bilaterality. In group B, 37 patients (14.02%) showed multifocality and seven patients (43.35%) showed bilaterality. They did not differ significantly between the two groups (P=.811, P=.182). There was a higher frequency of lymph node metastases in group A (52/86, 60.47%) than in group B (7/16, 43.75%, P=.214). Recurrence was observed in only two patients who had received thyroid lobectomy as the initial surgery in group A.


CONCLUSIONS
Intra-operative frozen biopsy can be a useful method for identifying the microscopic ETE. During the surgery, it can also help the surgeon to decide the optimal extent of surgery and the need for central compartment neck dissection in PTC patients.
Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.
J C
http://orcid.org/0000-0002-3734-0397
JC
Hong
Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.
J W
JW
Seo
Department of Medical Engineering, Dong-A University Graduate School, Busan, Korea.
A L
AL
Jang
Department of Endocrinology and Metabolism, Dong-A University College of Medicine, Busan, Korea.
S H
SH
Suh
Department of Pathology, Dong-A University College of Medicine, Busan, Korea.
M G
MG
Pak
Department of Family Medicine, Dong-A University College of Medicine, Busan, Korea.
S H
SH
Han
Department of Family Medicine, Dong-A University College of Medicine, Busan, Korea.
Y J
YJ
Park
Department of Otolaryngology-Head and Neck Surgery, In-Je University College of Medicine, Busan, Korea.
D K
DK
Lee
Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.
H S
HS
Park
Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.
M K
MK
Kang
D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery*; D005629:Frozen Sections; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018579:Patient Selection; D015203:Reproducibility of Results; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery*; D013965:Thyroidectomy; D016896:Treatment Outcome
extrathyroidal extension; frozen section; intra-operative; thyroid cancer