Abstract
BACKGROUND: Low-grade appendiceal mucinous neoplasms are papillary or flat mucinous tumors with low-grade cytologic atypia. They are the most frequent source of pseudomyxoma peritonei. They can be easily misdiagnosed, due to unspecific symptoms, with acute appendicitis, retroperitoneal tumors or adnexal mass. Cases of huge appendiceal mucinous neoplasms are even more extremely rare. CASE SUMMARY: We report a 54-year-old patient who presented with a 10-month history of constant dull distension accompanied by nausea. A surgical procedure of total hysterectomy, bilateral adnexectomy, appendectomy, greater omentectomy and right hemicolectomy was performed as a result of the findings on ultrasound, computed tomography scan and magnetic resonance imaging. Diagnosis was made after the pathological examination, which revealed low-grade appendiceal mucinous neoplasm. The patient received hyperthermic intraperitoneal chemotherapy with cisplatin and was discharged from the hospital. CONCLUSION: Low-grade appendiceal mucinous adenomas are rare tumors that are easily misdiagnosed, and a more thorough clinical workup is required to make a definitive diagnosis.