Predictive factors for occult contralateral carcinoma in patients with unilateral papillary thyroid microcarcinoma by preoperative ultrasonographic and pathological features.
BACKGROUND
The surgical extent and indication for treatment in patients with papillary thyroid microcarcinoma (PTMC) remain a controversial issue. The aim of this study was to investigate the predictive factor for contralateral occult carcinoma in patients with unilateral PTMC by preoperative ultrasonographic and pathological features.


METHODS
Of the total patients who underwent thyroidectomy, 455 patients with PTMC confined to one unilateral lobe as diagnosed using preoperative ultrasonography (US) were enrolled in the study. Occult contralateral carcinoma was defined as tumor foci in the contralateral lobe that was not detected preoperatively, but was detected pathologically. All patients underwent preoperative US review to investigate the US features of PTMC such as laterality, location, size, internal component, echogenicity, margin, calcification shape, multifocality, bilaterality, extrathyroidal extension, and location with respect to the trachea. Clinicopathological data were also analyzed.


RESULTS
Of the total of 455 patients who underwent total thyroidectomy for preoperatively detected unilateral PTMC, 71 patients (15.6 %) had contralateral occult carcinoma. Clinicopathological characteristics did not significantly differ between patients with and without contralateral occult carcinoma. Multivariate analysis showed that the absence of a well-defined margin and the presence of a probably benign nodule in the contralateral lobe were independent predictive factors for contralateral occult carcinoma in patients with unilateral PTMC in preoperative US images.


CONCLUSIONS
We demonstrated that an absence of a well-defined margin and the presence of a probably benign nodule in the contralateral lobe were independent predictive factors for contralateral occult carcinoma in patients with unilateral PTMC in preoperative US. The prediction of contralateral occult carcinoma in unilateral PTMC using preoperative US features could be useful for determining the optical extent of surgery.
Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Kyung Hee University, #1 Hoegi-dong, Dongdaemun-gu, Seoul, 130-702, Korea.
Young Chan
YC
Lee
Young Gyu
YG
Eun
Yu-Mee
YM
Sohn
Sang Youl
SY
Rhee
Il Ki
IK
Hong
Suk
S
Chon
Seung Joon
SJ
Oh
Deog Yoon
DY
Kim
D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D057234:Preoperative Period; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D014134:Tracheal Neoplasms / Q000473:pathology; D014463:Ultrasonography