Appendiceal mucocele is a rare clinical condition characterized by dilatation of the appendix lumen due to abnormal mucin secretion. It may be due to inflammatory conditions or neoplastic lesions. Mucocele may occur as a result of mucosal hyperplasia, mucinous cystadenoma or mucinous cystadenocarcinoma histopathologically. Mucinous cystadenoma is the most common form and it manifests itself as many different clinical pictures. It is detected in 0.2‒0.3%of appendectomy specimens. As preoperative diagnosis is often difficult, it is generally detected during laparotomy. Appendiceal mucocele is a clinical challenge for surgeons due to its risks of perforation and dissemination. Although there is no consensus for type of surgical treatment, appendectomy or right hemicolectomy are usually prefered. Herein, we present an appendiceal mucocele cystadenoma case with right lower quadrant pain and palpable mass who was followed up with the pre-diagnosis of plastron appendicitis in the context of the literature.