CDX2 and adenocarcinoma: Our study showed papillary structures in serous carcinoma of the ovary and cell ball formation in various adenocarcinomas, for example, breast carcinoma.IHC is considered a simple, reliable, and commonly used technique for determining the primary site of malignancies and investigating the prognosis and progression of malignant tumors [14-16].Several IHC stains, including TTF1, BerEP4, Calretinin, ER, CDX2, and WT1, were used in our study.