Giti Noghabaei - MD, Internist, Imam Hossein hospital, Iran university of medical Sciences
Maliheh Arab - Professor of Gynecology-Oncology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Ghazaleh Fazli - MS.c of developmental biology, Science and Research University of Tehran, Tehran, Iran
Golnaz Fallah-Talouki - Asistant of Obstetrics & Gynecology,Imam Hossein Medical center ,Shahid Beheshti University of Medical Sciences Tehran,Iran
Masoomeh Raoufi - Assistant Professor of Radiology, Imam Hossein Medical center ,Shahid Beheshti University of Medical Sciences Tehran,Iran
Hamed Tahmasebi - Department of Surgery,Imam Hossein Hospital,Shahid Beheshti University of Medical Sciences,Tehran,Iran
Behnaz Ghavami - Obstetricion&Gynecologist,Fellowship of Laparoscopy, Tehran University of Medical Sciences Tehran,Iran

Background & Objective: Low-grade appendiceal mucinous neoplasm (LAMN) is a very rare condition, diagnosed in ۰.۲-۰.۷% of appendectomies. The pathophysiology of the neoplasm involves accumulation of large volume of mucin in the appendiceal lumen, resulting in its obstructive dilation. Most epithelial tumors affecting the appendix are of the mucinous type and are manifested by mucin accumulation within an inflamed appendix with fibrotic and hyalinized wall. Case presentation: A ۲۹-year-old female presented with a history of chronic and intermittent episodes of abdominal pain and a palpable mass in the right lower abdominal quadrant. Sonography showed a ۵۸ mm mass anterior to the uterus and adjacent to the ovary, probably a uterine myoma. Laparotomy revealed normal uterus, and ovaries with a translucent mass originating from the appendix and fixed to the cecum. Pathologic examination of the mass was reported as low grade appendiceal mucinous neoplasm. Conclusion: This is a rare case of appendiceal mucocele in a young female, mimicking a pelvic mass, which was misinterpreted by sonography as a gynecologic solid mass near the uterus. Preoperative diagnosis of appendiceal mucocele is important due to the risk of concurrent GI and ovarian malignancy associated with the condition.

Mucocele, Appendix, Pseudomyxoma Peritonei, low-grade appendiceal mucinous neoplasm