Large mucinous neoplasm of the appendix mimicking adnexal mass in a postmenopausal woman

INTRODUCTION: Appendiceal tumors are rare, late-diagnosed neoplasms that may not be differentiated from adnexal masses even by advanced imaging methods and other diagnostic procedures. They may be asymptomatic and remain undiagnosed until surgery. PRESENTATION OF CASE: We report a case of 81-year-old postmenopausal woman presented with abdominal pain. A magnetic resonance imaging revealed right adnexal mass. Laparotomy was performed and detected a 12 cm × 9 cm mucinous tumoral mass arising in the appendix. An appendectomy and a right hemicolectomy with ileo-transverse anastomosis were performed. Histopathological examination was revealed appendiceal mucinous neoplasm with low malignancy potential. DISCUSSION: Gastrointestinal tumors such as appendiceal tumors can mimicking adnexal mass. Therefore, appendiceal tumor kept in mind in a patient with diagnosed adnexal mass, especially patient had non-specific clinical symptoms, laboratory and radiologic findings. CONCLUSION: Gastrointestinal tumors such as appendiceal tumors kept in mind in a patient with diagnosed adnexal mass.