Appendiceal Intussusception Induced by cecal adenocarcinoma in Tubular Adenoma: a case report

Intussusception of the appendix is rare in worldwide studies and is difficult to recognize before operation. We report a case of a 58-year-old, previous healthy male with defecating tarry stool for 10 days with dizziness, general weakness. Double contrast colon series and abdominal computed tomography (CT) revealed a 2.5 cm pedunculated, polyp-like lesion adjacent to the ileocecal region, and the appendix was not found. The pathological findings of biopsy tissues of colonoscopy only showed inflammatory change. Appendiceal intussusception was finally recognized during the operation. The pathological report of the specimen from right hemicolectomy revealed a cecal adenocarcinoma in tubular adenoma. Appendiceal intussusception is an interesting variation of the appendiceal diseases that the colonoscopist, radiologist, and general surgeon must know and better to identify before operation to avoid possible perforation during biopsy. Correspondence Author to: She-Meng Cheng Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan No. 92, Sec. 2, Zhong-Shan N. Road, Taipei 104, Taiwan J Radiol Sci 2014; 39: 21-24 Appendiceal intussusception 22 J Radiol Sci March 2014 Vol.39 No.1 an enhancing finger-like soft tissue with a round base near the ileocecal valve, surrounded by fecal material (Fig. 3a, 3b). In the middle of the mass border, there was a triangular fat-density dimple with linear mesenteric vessels. Normal appearing appendix cannot be found (Fig. 3c). The lab data for pre-operative survey showed anemia (low hemoglobin level: 8.0g/dL), and elevated white blood cell count (13.50x103/uL). The radioimmunoassay for carcinoembryonic antigen (CEA) was 1.72ng/mL, within normal range. During the surgical laparotomy, the surgeon found a hard cecal mass, so right hemicolectomy and regional lymph node dissection were performed as a standard procedure for cecal malignancy. According to the operative note, the surgeon noticed that the appendix inverted into the cecum under gross inspection. There was a grayish polypoid tumor at cecal base measuring 3x2.5 cm in size with a 4x0.4cm appendix invaginated into the cecum. According to the imaging and surgical findings, a McSwain type V—complete intussusception of the appendix within the caecum—was impressed [3]. The histological findings showed tubular adenoma with adenocarcinoma component (Fig. 4a). The 4x0.4cm appendix was “outlined” by mucosal layer and was obliterated by mucus and fibrous tissue without inflammatory cell infiltration (Fig. 4b). The patient tolerated the whole procedure well and discharged 7 days after the operation and follow-up in outpatient department of the general surgery. Figure 1 Figure 1. Double-contrast barium enema showed a fingerlike filling defect at cecal base (arrows).