Cancer stem cells (CSCs) can undergo self-renewal and differentiation. EpCAM is a 40-kDa type I transmembrane glycoprotein composed of a large extracellular domain, one transmembrane region, and a small intracellular domain of 26 amino acids. Recent insights revealed that it is involved in promoting cancer cell proliferation, migration, and invasiveness. It is used as a diagnostic and prognostic marker. EpCAM has also recently been identified as a marker for CSCs.

Ovarian carcinoma is one of most frequent cancer in women worldwide. Epithelial ovarian carcinoma is a group of neoplasms with different histologic pictures. Serous carcinoma is the most common type.

Cancer stem cells (CSCs) can undergo self-renewal and differentiation. EpCAM is a 40-kDa type I transmembrane glycoprotein composed of a large extracellular domain, one transmembrane region, and a small intracellular domain of 26 amino acids. It is abundantly expressed by the majority of human epithelial carcinomas, including colorectal, breast, lung, prostate, ovarian, and endometrial cancers. it is overexpressed in various neoplasms. Recent insights revealed that it is involved in promoting cancer cell proliferation, migration, and invasiveness. It is used as a diagnostic and prognostic marker. EpCAM has also recently been identified as a marker for CSCs.

Inclusion Criteria:

• Patients with epithelial ovarian carcinoma and underwent surgery

Exclusion Criteria:

• - Cases received pre-operative chemotherapy or radiotherapy.
• Cases with insufficient clinical data.

Fifty paraffin blocks of EOC collected from the archive of Pathology Department of Sohag Faculty of Medicine during the time period from June 2017 to June 2022.