[Composite tumor of the colon with liver metastases]

Colorectal neuroendocrine carcinoma: A case report and review of the literature

BACKGROUND

Colorectal neuroendocrine carcinoma (NEC) is a rare tumor that demonstrates aggressive growth pattern with ingrowth into the tract, metastasis to the other organs, and invasion to the surrounding organs; these clinical characteristics result in poor prognosis. Surgical resection appears as an effective approach; however, because it is difficult to accurately diagnose NEC during the early stage and owing to its aggressive growth pattern, development of a reliable standard chemotherapy regimen and management strategies are essential.

CASE SUMMARY

Here, we report the case of patient with NEC showing an aggressive growth pattern that resulted in the rupture of the tumor to the outside the colon after stenting of the internal colonic stenosis. In addition, the tumor invaded into the duodenum, thereby causing duodenal stenosis that required an additional stent in the duodenum. This aggressive growth pattern is one of the main features of the NEC that is different from adenocarcinoma. To clarify the clinical characteristics, we reviewed 60 recently reported cases, including data on tumor location, size, treatment, and prognosis.

CONCLUSION

We consider that the information presented here is of great significance for the diagnosis, treatment, and management of symptoms of the patients with NEC.

A Case of Neuroendocrine Cell Carcinoma with Sigmoidovesical Fistula

Colonic neuroendocrine cell carcinoma (NEC), which is a rare subtype of colon epithelial neoplasm, has been reported to show extremely aggressive characteristics with a 1-year survival rate of 20%. We report herein a resected case of NEC that manifested bacterial sepsis due to sigmoidovesical fistula. Staged surgery consisted of resecting the sigmoid colon and part of the bladder four weeks after construction of an ileostomy to alleviate septic shock. The resected specimen was histologically diagnosed as NEC invading the wall of the urinary bladder with metastasis to the regional lymph nodes. The patient underwent four cycles of FOLFOX after surgery for additional treatment of residual metastatic lymph nodes around the abdominal aorta diagnosed preoperatively. Although the patient showed stable disease measured by computed tomography scan for the first three months after surgery, he rejected additional chemotherapy thereafter, and died ten months after the initial admission due to progression of residual tumor in the urinary bladder as well as the lymph nodes. This is the first case report describing colonic NEC manifesting perforation into the urinary bladder. Although the optimal chemotherapeutic regimen for colonic NEC has not yet been established, FOLFOX may be one of the choices.