Low-grade Mucinous Appendiceal Neoplasm: a Tumor in Disguise of Appendicitis.

Appendiceal mucinous neoplasms are a rare malignancy, but it is an important diagnostic entity. Ultrasonography and CT scan represent useful method for diagnosis; however, diagnosis is often incidental or intraoperative finding at resection for suspicion of appendicitis. Appendiceal mucinous neoplasm is commonly misdiagnosed as acute appendicitis, adnexal mass, or retroperitoneal tumors. Our case represents the importance of developing a high index of suspicion of appendiceal malignancy and mucocele rupture in patients who are planned for appendectomy. There is risk of second malignancy mostly of ovary, breast, kidney, and gastrointestinal tract simultaneously in about 30% of patients of appendiceal mucinous neoplasm. Low-grade mucinous neoplasm has excellent prognosis after standard appendectomy. Advanced stage low-grade mucinous neoplasm involving periappendiceal area or with nodal metastasis is treated by appendectomy with right hemicolectomy and lymph node dissection. We report a case of low-grade appendiceal mucinous neoplasm in a 65-year-old female with past history of surgery for benign bilateral adnexal lesions.