[428] Galectin-3 and BRAF Mutation in Cases of Cytologically Suspicious of Papillary Carcinoma

DK Kim, HK Kim, JY Kwak, MJ Kim, HJ Jung, JS Koo, BJ Lim, CK Jung, SW Hong. Yonsei University College of Medicine, Seoul, Korea; Catholic University St. Mary's Hospital, Seoul, Korea

Background: Fine needle aspiration, known as the most accurate and cost-effective manner, still have some chances of indeterminate cases which are pauci-cellular and showing minor nuclear atypia, but most of are suspicious of papillary thyroid carcinoma (PTC). BRAF mutation was found about half of the PTC and galectin-3 as expressed by malignant tumor, helping us to differentiate malignancy from benign lesion.
Design: Subjected cases included 44 cases previously diagnosed as suspicious of PTC with cytologic examination which were confirmed with PTC after tissue examination and 4 benign controls. The subjected cases were analyzed the galectin-3 expression by immunohistochemical staining and the BRAF mutation by PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) with new restriction enzyme.
Results: All 44 cases of PTC and 2 out of 4 benign controls revealed galectin 3 expression. BRAF mutation was found in 9 cases of PTC only.

Prevalence of positivity of galectin-3 and BRAF mutation in cytology specimen

Category(n)	Galectin-3 (+)		Galectin-3 (-)
	BRAF(+)	BRAF(-)	BRAF(+)	BRAF(-)
cPTC (40)	8	32	0	0
fvPTC (2)	0	2	0	0
dsPTC (1)	0	1	0	0
cmPTC (1)	1	0	0	0
Benign (18)	0	8	0	10

cPTC: conventional papillary thyroid carcinoma, fvPTC: follicular variant papillary thyroid carcinoma, dsPTC: diffuse sclerosing variant papillary thyroid carcinoma, cmPTC: cribriform morular variant papillary thyroid carcinoma

Statistical analysis of single and combined galectin-3 and BRAF mutation in cytology specimen

	Sensitivity	Specificity	Accuracy	PPV	NPV
BRAFV600E	20.4	100	43.5	100	33.9
Galectin-3	100	55.5	87	84.6	100
Galectin-3 and BRAFV600E	100	100	100	100	100
Galectin-3 or BRAFV600E	100	55.5	87	84.6	100

PPV; positive predictive value, NPV; negative predictive value


Conclusions: Assessment of galectin-3 expression demonstrates high sensitivity but low specificity. Evaluation of the BRAF mutation revealed high specificity and low sensitivity. This study suggests that the combination of the two methods in cytology diagnosis of PTC will be complementary.
Category: Cytopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 99, Tuesday Morning