Introduction/Background Metastatic tumors of the appendix are rare. Endometrial cancer tends to metastasize by directly invading close structures; the lung, liver, bones, and brain are common sites of distant metastasis. Therefore, the aim of this surgical video is to demonstrate uncommon spread pattern of the endometrial cancer.

Methodology A step-by-step explanation of the procedure which was performed on the patient using a video.

Results The article provides information about the authors' clinical observation of a 69-year-old patient with uterine cancer metastasized to the appendix. The patient underwent complex clinical, laboratory and instrumental examinations, and during the pelvic MRI examination, a 22x14 mm tumor was found in the endometrial cavity. Abdomen CT scan with oral and intravenous contrast revealed a pathological mass of 22x14 mm in the uterine cavity, as well as a 50x40 mm tumor in the appendix. The right hemicolectomy + total abdominal hysterectomy + bilateral salpingo-oophorectomy + total omentectomy + ileotransvers anastomosis were carried out in the department of Gynecological Oncology, Azerbaijan Medical University. Pathological examination of the material revealed endometrial carcinoma in the uterine body, the appendix with endometrioid carcinoma infiltration (metastasis) in the wall. Metastasis was found in 5 of the lymph nodes. The postoperative period was uneventful.

Conclusion This case demonstrates that metastatic tumors can naturally fuse with the tissue at the site of metastasis. A correct diagnosis should be made by combining the patient’s medical history with morphologic and immunohistochemical test results. The differentiation between primary and metastatic tumors is important for staging the tumor, choosing appropriate treatment, and estimating prognosis.

Disclosures Endometrium, Appendix, Adenocarcinoma, Metastasis.