Amucinous appendix tumor is a rare disease. According to the WHO, mucinous neoplasms can vary in 4 histological types, which are both benign and malignant. A lately diagnosed disease is often associated with a low-symptom disease course.

Purpose. A clinical case demonstrates the experience of treating women of 45 years with a malignant mucinous appendix tumor, diagnosed in a planned manner, on an outpatient basis.

Materials and methods. This clinical case presented in current article demonstrates the difficulties of early diagnosis and successful surgical treatment of mucinous appendix tumor using laparoscopic technologies. A comprehensive examination was prescribed for the patient: colonoscopy, ultrasound examination of the abdominal cavity and pelvis, gynecologist consultation, as well as MSCT of the chest and abdominal cavities with intravenous contrast, clinical and laboratory examination.

Conclusions. The «gold» standard in the diagnosis of appendix mucinous neoplasms is computed tomography of the abdominal cavity with contrast enhancement. Patients with suspected appendix tumors should be examined in full with mandatory colonoscopy, abdominal MSCT with intravenous contrast and determination of the level of cancer markers CA125, CA19-9 and CEA. Timely diagnosis, an adequate amount of surgical intervention and a qualitative pathomorphological study of the surgical preparation allow achieving good results in the treatment of mucinous neoplasms of the appendix.