Colon intussusceptions caused by a low-grade appendiceal mucinous neoplasm

Excerpt

A 43-year-old woman presented with right lower quadrant pain that had persisted for several days. She had a cesarean section, but there was no past illness or other medical history. A physical examination confirmed tenderness in the right lower quadrant of the abdomen. Blood tests including tumor markers were within the normal range. Contast-enhanced computed tomography (CT) of abdomen showed colonic intussusception located in the transverse colon, where a cystic tumor was found (Fig. 1a). A colonoscopy was performed under CO₂ injection, which diagnosed a cystic tumor. Pushing the tumor and insufflation of CO₂ enabled reduction of the intussusception. After reduction, the tumor was elastic and hard and was visualized as a submucosal tumor in the cecum (Fig. 1b). Biopsy specimens did not reveal a definitive diagnosis. She was relieved of abdominal pain after reduction, but she developed intussusception again the next day. Then, she underwent an elective laparoscopy-assisted ileocecal resection with lymph node dissection (D₂). Macroscopically, the resected specimen was a unilocular cyst filled with mucus with a diameter of 40 mm (Fig. 2a). Pathologically, mucin-producing epithelial cells with low atypia were confirmed (Fig. 2b) with no lymph node metastasis. These findings confirmed a low-grade appendiceal mucinous neoplasm (LAMN), and her follow up was terminated.

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