Ultrasonography should not guide the timing of thyroidectomy in pediatric patients diagnosed with multiple endocrine neoplasia syndrome 2A through genetic screening.
BACKGROUND
American Thyroid Association (ATA) guidelines suggest that thyroidectomy can be delayed in some children with multiple endocrine neoplasia syndrome 2A (MEN2A) if serum calcitonin (Ct) and neck ultrasonography (US) are normal. We hypothesized that normal US would not exclude a final pathology diagnosis of medullary thyroid cancer (MTC).


METHODS
We retrospectively queried a MEN2A database for patients aged<18 years, diagnosed through genetic screening, who underwent preoperative US and thyroidectomy at our institution, comparing preoperative US and Ct results with pathologic findings.


RESULTS
35 eligible patients underwent surgery at median age of 6.3 (range 3.0-13.8) years. Mean MTC size was 2.9 (range 0.5-6.0) mm. The sensitivity of a US lesion≥5 mm in predicting MTC was 13% [95% confidence interval (CI) 2%, 40%], and the specificity was 95% [95% CI 75%, 100%]. Elevated Ct predicted MTC in 13/15 patients (sensitivity 87% [95% CI 60%, 98%], specificity 35% [95% CI 15%, 59%]). The area under the receiver operating characteristic curve (AUC) for using US lesion of any size to predict MTC was 0.50 [95% CI 0.33, 0.66], suggesting that US size has poor ability to discriminate MTC from non-MTC cases. The AUC for Ct level at 0.65 [95% CI 0.46, 0.85] was better than that of US but not age [AUC 0.62, 95% CI 0.42, 0.82].


CONCLUSIONS
In asymptomatic children with MEN2A diagnosed by genetic screening, preoperative thyroid US was not sensitive in identifying MTC of any size and, when determining the age for surgery, should not be used to predict microscopic MTC.
Section of Surgical Endocrinology, Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Lilah F
LF
Morris
Steven G
SG
Waguespack
Beth S
BS
Edeiken-Monroe
Jeff E
JE
Lee
Thereasa A
TA
Rich
Anita K
AK
Ying
Carla L
CL
Warneke
Douglas B
DB
Evans
Nancy D
ND
Perrier
Elizabeth G
EG
Grubbs
D000293:Adolescent; D019540:Area Under Curve; D002116:Calcitonin / Q000097:blood*; D018276:Carcinoma, Medullary / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D018813:Multiple Endocrine Neoplasia Type 2a / Q000000981:diagnostic imaging* / Q000235:genetics / Q000601:surgery*; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013964:Thyroid Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D013965:Thyroidectomy; D014463:Ultrasonography
D002116:Calcitonin; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human