Mylinh T. Mac, MD
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA

Fai Chung
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA

Fan Lin, MD, PhD
Department of Laboratory Medicine, Geisinger Medical Center, Danville, PA

Pei Hui, MD, PhD
Department of Pathology, Yale University School of Medicine, New Haven, CT

Bonnie L. Balzer, MD
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA

Hanlin L. Wang, MD, PhD
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA

Keywords: Small intestine; Colorectal; Adenocarcinoma; Carbamoyl phosphate synthetase 1; Hepatocyte antigen; Hep Par 1

Upon completion of this activity, you will be able to:

• describe the pattern of Hep Par1 immunoreactivity in nonneoplastic small intestinal and colonic epithelium.
• define the usefulness of Hep Par 1 immunostaining in the differential diagnosis of various hepatocellular and nonhepatocellular neoplasms.