Objective: We discuss the case of a 58-year-old woman who presented with right lower quadrant pain and fever. CT showed a right lower quadrant inflammatory mass presumed to be an appendiceal abscess. The patient underwent open drainage of the mass but failed to return for an interval appendectomy. She returned 23 months later with a recurrent right lower quadrant inflammatory mass treated initially with percutaneous drainage followed by interval appendectomy. The final pathologic diagnosis was mucinous cystadenoma with perforation.
Conclusion: Primary neoplasms of the appendix are uncommon but should be considered in the correct clinical and imaging scenario.