Carcinoembryonic Antigen (CEA), Pancreatic Cyst Fluid

CPT CODE:

USEFUL FOR:

When used in conjunction with imaging studies, cytology, and other pancreatic cyst fluid tumor markers:
 - Distinguishing between benign (inflammatory cysts, pseudocysts)   and malignant pancreatic cysts
 - Determining the likely type of malignant pancreatic cyst

SPECIMEN REQUIRED:

1 mL of pancreatic cyst fluid. Send specimen frozen in plastic vial.

TRANSPORT TEMPERATURE:

Frozen\Refrig OK\Ambient NO

CLINICAL INFORMATION:

Cystic lesions of the pancreas are of various types including: Benign cysts:- Inflammatory cysts (pseudocysts)- Serous cysts (serous cystadenoma)Mucinous cysts:- Premalignant (mucinous cystadenoma)- Malignant (cystadenocarcinoma, intrapapillary mucinous    neoplasia)
The diagnosis of pancreatic cyst type is often difficult and mayrequire correlating imaging studies with results of cytologic examination and tumor marker testing performed on cyst aspirates. Various tumor markers have been evaluated to distinguish nonmucinous, nonmalignant pancreatic cysts from mucinous cysts, which have a high likelihood of malignancy.Carcinoembryonic antigen (CEA) has been found to be the mostreliable tumor marker for identifying those pancreatic cysts that arelikely benign (CEA <30 ng/mL).(1,2) In cyst aspirates, CEAconcentrations > or =30 ng/mL are suspicious for mucinous cysts.The greater the CEA concentration, the greater the likelihood thatthe mucinous cyst is malignant. However, CEA testing does notreliably distinguish between benign, premalignant, or malignantmucinous cysts. CEA test results should be correlated with the results of imaging studies, cytology, other cyst fluid tumor markers(ie, amylase and CA 19-9), and clinical findings for diagnosis.
See "Pancreatic Cyst Fluid Markers - Interpretive Algorithm" in Special Instructions

CLINICAL INTERPRETATION:

A pancreatic cyst fluid CEA concentration of > or =30 ng/mL is suspicious for a mucinous cyst but is not diagnostic. The sensitivity and specificity for mucinous lesions are approximately70% to 80% at this concentration.(2) Other pancreatic lesions mayhave CEA concentrations >30 ng/mL, including cystic lesionsrelated to nonmucinous pancreatic carcinoma. CEA <30 ng/mLis more consistent with serous cystadenomas, inflammatory cystsand pseudocysts, metastatic lesions from tumors elsewhere, andcystic lesion related to nonmucinous pancreatic carcinoma.However, exceptions have been observed in which malignantcysts have low concentrations of CEA, and pseudocysts andserous cysts have high CEA. Correlation of CEA test resultswith cytology and imaging is recommended.
In conjunction with CEA, other markers can assist in determiningthe type of pancreatic cyst: -Amylase concentrations of <350 U/L with CEA <30 ng/mL are   consistent with serious cystadenomas -Amylase concentrations >8500 with CEA <30 ng/mL are   consistent with pancreatic pseudocysts - CA 19-9 concentrations <8000 U/mL with CEA > or =30 ng/mL    is suggestive of an intraductal papillary mucinous neoplasia    (IPMN)

REFERENCE VALUES:

An interpretive report will be provided.