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.

Endocrine cell carcinomas of the colon and rectum: a clinicopathological evaluation

PURPOSE

Endocrine cell carcinoma, according to the Japanese classification criteria for colorectal cancer, corresponds to neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma (MANEC), as defined in the 2010 World Health Organization (WHO) classification. We retrospectively reviewed the clinical features of patients with these tumors diagnosed and treated at our institution.

METHODS

The clinicopathological features of endocrine cell carcinomas of the colon and rectum diagnosed by neuroendocrine markers from January 2000 to December 2012 were retrospectively evaluated in 12 patients.

RESULTS

Surgical specimens were obtained from eight of the 12 patients. MANEC was diagnosed in six patients and NEC in one. One tumor was unclassifiable. The tumors were not resected in four patients, and all died within 3 months. Of the eight patients who underwent resection, four received an R0 resection, two of whom underwent adjuvant chemotherapy and survived more than 5 years. One patient who underwent an R2 resection and continuous chemotherapy survived for 53 months. One patient with NEC underwent surgery and radiotherapy, and died 17 months later.

CONCLUSION

Most endocrine cell carcinomas of the colon and rectum reviewed were MANECs. Though their prognosis was generally poor, chemotherapy may be effective in some patients.

Mixed adenoneuroendocrine carcinoma of the colon progressed rapidly after hepatic rupture: report of a case

The rupture of a metastatic mixed adenoneuroendocrine carcinoma (MANEC) has not been previously reported, although the neuroendocrine cell carcinoma is often associated with a high incidence of hepatic metastases. The patient was a 39-year-old male who presented with upper abdominal pain over 3 months. Computed tomography showed multiple tumors in both hepatic lobes, while lower gastrointestinal endoscopy revealed a tumor in the transverse colon. Histopathologic examination of the tumor revealed it to be a neuroendocrine cell carcinoma. After the resection of the primary tumor, hepatic metastases rapidly increased, and one of them in the left lateral segment was ruptured with significant hemorrhage. The rupture led us to undertake the emergency operation to stop the bleeding. Histology showed a high-grade large-cell neuroendocrine carcinoma associated with moderately differentiated tubular adenocarcinoma. The Ki-67 labeling index was 80% (G3). The diagnosis was mixed adenoneuroendocrine carcinoma according to the 2010 World Health Organization guidelines. Hepatic arterial infusion chemotherapy, systemic chemotherapy, and transcatheter arterial chemoembolization did not decrease the tumor progress, and the patient died on postoperative day 110. Reporting this highly malignant case, I hope all doctors can be interested in MANEC.