Abstract
We report a case of appendiceal adenoendocrine cell carcinoma. A 75-year-old man reporting fever and general fatigue consulted a general practitioner was referred to our hospital and found to have a tumor without tenderness in the right lower abdomen. He was found in abdominal computed tomography (CT) to have appendiceal swelling with wall thickening and two liver tumors with low-density contrast were detected at S7 and S8, yielding a diagnosis of appendiceal cancer with suspected multiple liver abscesses, necessitating ileocecal resection. The resected 90×52 mm appendiceal tumor showed a rough villous pattern with no internal mucus retention. Pathological findings showed partial neuroendocrine differentiation in ordinarily differentiated adenocarcinoma. Immunohistochemically, tumors positively expressed synaptophysin. The primary appendiceal tumor was diagnosed as adenoendocrine cell carcinoma and liver tumors were diagnosed as abscesses due to their disappearance postoperatively. Such adenoendocrine cell carcinoma of the appendix is rare and only 5 cases have been reported in the literature in Japan.
