Small-cell Neuroendocrine Carcinoma Associated with Non Adenoma-like Raised Lesion in a Patient with Long-standing Ulcerative Colitis

Neuroendocrine carcinoma associated with chronic ulcerative colitis: a case report and review of the literature

Adenocarcinoma is a common histological type of ulcerative colitis-associated cancer (UCAC), whereas neuroendocrine carcinoma (NEC) is extremely rare. UCAC is generally diagnosed at an advanced stage, even with regular surveillance colonoscopy. A 41-year-old man with a 17-year history of UC began receiving surveillance colonoscopy at the age of 37 years; 2 years later, dysplasia was detected in the sigmoid colon, and he underwent colonoscopy every 3 to 6 months. Approximately 1.5 years thereafter, a flat adenocarcinoma lesion occurred in the rectum. Flat lesions with high-grade dysplasia were found in the sigmoid colon and surrounding area. The patient underwent laparoscopic total proctocolectomy and ileal pouch-anal anastomosis with ileostomy. Adenocarcinoma was diagnosed in the sigmoid colon and NEC in the rectum. One year postoperation, recurrence or metastasis was not evident. Regular surveillance colonoscopy is important in patients with long-term UC. A histological examination of UCAC might demonstrate NEC.

Risk factors for the postoperative recurrence of ulcerative colitis-associated colorectal cancer

PURPOSE

Although ulcerative colitis-associated colorectal cancer (UC-CRC) has been described, there are few reports regarding recurrent cases of UC-CRC. In this study, we investigated the risk factors for UC-CRC recurrence.

METHODS

Recurrence-free survival (RFS) was determined for 144 stage I to III cancer patients among 210 UC-CRC patients from August 2002 to August 2019. The Kaplan‒Meier method was used to obtain the cumulative RFS rate, and the Cox proportional hazard model was used to extract recurrence risk factors. The interaction term between cancer stage and prognostic factors specific to UC-CRC was evaluated using the Cox model. The Kaplan‒Meier method was applied by cancer stage to the UC-CRC-specific prognostic factors for which interaction effects were indicated.

RESULTS

There were 18 cases of recurrence involving patients with stage I to III cancer, and the recurrence rate was 12.5%. The cumulative 5-year RFS rate was 87.5%. Multivariable analysis showed that age at surgery (hazard ratio (HR): 0.95, 95% CI: 0.91-0.99, p = 0.02), undifferentiated carcinoma (HR: 4.42, 95% CI: 1.13-17.24, p = 0.03), lymph node metastasis (HR: 4.11, 95% CI: 1.08-15.69, p = 0.03), and vascular invasion (HR: 8.01, 95% CI: 1.54-41.65, p = 0.01) were significant risk factors for recurrence. Patients with stage III CRC in the young adult (age < 50 years) group had a significantly worse prognosis than those in the adult (age ≥ 50 years) group (p < 0.01).

CONCLUSION

Age at surgery was identified as a risk factor for UC-CRC recurrence. Young adult patients with stage III cancer may have a poor prognosis.

Poorly Differentiated Neuroendocrine Carcinoma of the Sigmoid Tract in Long-Standing Ulcerative Colitis: Report of a Case and Review of the Literature

A 37-year-old male with long-standing and extensive ulcerative pancolitis developed a rapidly lethal poorly differentiated neuroendocrine carcinoma (NEC) in the sigmoid colon. Prior biopsies obtained from multiple sites of the colon during endoscopic surveillance showed minimal inflammatory changes and no sign of dysplasia. Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal malignancies, and adenocarcinoma is the most common type of colorectal neoplasm associated with ulcerative colitis and Crohn’s disease, but other types of epithelial and nonepithelial tumors have also been described in IBD. NECs arising in the setting of ulcerative colitis are very rare and are reported as anecdotic findings. We describe the clinicopathological features of an IBD-related NEC and review the previously reported cases.

A case of rectal neuroendocrine carcinoma in a patient with long-standing ulcerative colitis involving alterations of the p16-Rb pathway

The patient was a 54-year-old male who had been suffering from extensive ulcerative colitis (UC) for 17 years. Colonoscopy revealed an elevated lesion in the affected rectum, and its biopsy demonstrated neuroendocrine carcinoma (NEC). The surgical specimen obtained on laparoscopic high anterior resection showed extensive active inflammatory and dysplastic lesions and three grossly visible multifocal malignant lesions: a polypoid fungating tumor of NEC (type 1, 20 mm in diameter, pT3) that had been preoperatively noticed, a polypoid fungating tumor of adenocarcinoma (type 1, 22 mm, pT2) and a protruded sessile polypoid tumor (0-Is, 5 mm, pTis) of adenocarcinoma. The NEC was adjacently accompanied by dysplasia-carcinoma sequential lesions and showed a diffuse immunohistochemical overexpression of p53 and p16 proteins and the loss of Rb with no abnormal immunohistochemical staining of microsatellite instability markers and no KRAS mutations. Fifteen months later, the patient showed liver metastasis from the NEC component, followed by bone and spinal metastasis; he died 22 months after the initial diagnosis. A rare case of lethal NEC arising from long-standing extensive UC was reported. The NEC appeared to be UC-related, not incidental, and complicated by progression from dysplasia to carcinoma involving alterations of the p16-Rb pathway.