Low-grade appendiceal mucinous tumor complicated by intussusception.

RATIONALE: Appendiceal mucinous tumors with intussusception are extremely rare. As primary lesions, malignant tumors often present with atypical clinical symptoms, which increases the likelihood of misdiagnosis.

PATIENT CONCERNS: A 79-year-old female patient of Miao ethnicity in Guizhou Province, China, was admitted with intermittent paroxysmal abdominal pain for 20 days and abdominal distension for 3 days.

DIAGNOSES: Computed tomography revealed ileal intussusception in the lower abdomen, suspected to be associated with a tumor.

INTERVENTIONS: Laparoscopy-assisted right hemicolectomy was performed.

OUTCOMES: Postoperative histopathology showed a low-grade appendiceal mucinous tumor with mucinous components extending into the muscularis propria and localized calcification. Regular follow-up was recommended.

LESSONS: Low-grade appendiceal mucinous tumors are extremely rare and are even less common when complicated by intussusception. Their clinical presentation is nonspecific, which may result in missed diagnosis. Therefore, thorough preoperative evaluation and careful surgical planning are essential for improving prognosis and minimizing the risk of severe complications.