Alternate Test Names:
Hepatocyte; CSP1; Carbamoyl phosphate synthetase 1

Methodology: IHC

Clinical Significance:
Identifies: Carbamoyl phosphate synthetase 1, a mitochondrial protein present in hepatocytes and hepatocellular carcinoma. When used as part of a panel of other markers, HepPar1 is useful in distinguishing hepatocellular carcinoma from cholangiocarcinoma and metastatic carcinomas to the liver. However, carbamoyl phosphate synthetase 1 is also expressed in a subset of gastric carcinomas as well as ‘hepatoid’ carcinomas of various organs.

Subcellular Localization: Cytoplasmic, granular

Organ: Liver

Disease State: Carcinomas of Unknown Primary, Hepatocellular Carcinoma

CPT Code(s): 88342 or 88341 (reference only; CPTs may vary)

Turnaround Time: Within 1-2 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Formalin-fixed, paraffin-embedded (FFPE) tissue block or cell block - OR -
• 1 unstained slide for each test requested plus 3-4 additional unstained slides cut at 4µm