Table 2.

Cyst fluid studies

Cyst fluid test	Test characteristics	Diagnosis
String sign ≥ 1 cm, ≥ 1 s	95% specificity, 94% positive predictive value	Mucinous
Cyst fluid cytology	63% sensitivity	-
Cyst wall cytology	29% increased diagnostic yield	-
CEA > 192 ng/mL	75% sensitivity, 84% specificity	Mucinous
CEA < 5 ng/mL	50% sensitivity, 95% specificity	Serous cystadenoma, pseudocyst, cystic neuroendocrine tumor
Amylase < 250 U/L	44% sensitivity, 98% specificity	Excludes pseudocyst
Glucose < 50 mg/dL	89% sensitivity, 78% specificity	Mucinous
KRAS/GNAS mutation	89% sensitivity, 100% specificity	Mucinous

CEA: Carcinoembryonic antigen.