Abstract
Endocrine cell carcinoma (ECC) of the rectum is a relatively rare neoplasm with a poor prognosis. The mechanisms of its development and progression remain unclear, and there is no established remedy. We reported a long surviving case of early ECC of the rectum with lymph node involvement. A 57-year-old man with melena was found to have rectal cancer by endoscopy. The tumor was biopsied and diagnosed immunohistochemically as ECC. He underwent low anterior resection with lymph node dissection on October, 2003. Histopathologically, the tumor was composed of fascicular proliferation cells invading the submucosal layer and had lymph node metastasis. Moreover, the tumor cells were immunohistochemically positive for both NCAM and synaptophysin, confirming the diagnosis of ECC. Well differentiated adenocarcinoma (WDA) and tubulovillous adenoma (TVA) coexisted with ECC in the tumor. p53 staining was positive in TVA, WDA and ECC. The MIB-1 index of ECC was higher than those of TVA and WDA. He was discharged on postoperative day 24. He underwent adjuvant chemotherapy with UFT/LV and 5-DFUR. He is alive without recurrence, 8 years and 7 months since surgery. This case suggests that ECC has a high potential of lymph node metastasis and that colectomy with lymphadenectomy is essential to long-term survival even in early cancer. The morphological appearances in this case provide some information on the pathogenesis of ECC.
