Mucinous neoplasms of the appendix and ovary: confusing terminology and clinical impact

Mucinous tumors may arise from a variety of anatomic locations; however, their clinical behavior varies considerably depending on their origin. When mucinous tumors involve the abdominal cavity, it may lead to mucinous ascites, clinically known as pseudomyxoma peritonei. While most cases are derived from the appendix, it may arise from a mucinous tumor of the ovary. However, the biological potential of these lesions vary, which is reflected by their recently updated classification schemes. This article is intended to clarify the different classifications of the mucinous tumors derived from the appendix and those derived from the ovary, and to provide therapeutic guidance for clinicians. This may facilitate better communication between pathologists and clinicians, and optimize therapeutic decision making.