Metastatic Large Cell Neuroendocrine Carcinoma of the Colon: A Case Report

Abstract

Colorectal neuroendocrine tumors are rare entities, with large cell neuroendocrine carcinomas occurring less frequently. We report a case of an 83-year-old male who presented with symptoms of intestinal obstruction. A computed tomography scan of the abdomen and pelvis revealed a high-grade large bowel obstruction secondary to an irregular exophytic soft tissue mass within the ascending colon, with extensive metastatic disease. He subsequently underwent a right hemicolectomy. Histologic evaluation revealed large cell neuroendocrine carcinoma of the colon. Standardized treatment modalities have not been established; however, chemotherapy is often used as the first-line or adjuvant therapy with surgery. Unfortunately, our patient succumbed to postoperative complications on day 30 of the hospital stay.

Large cell neuroendocrine carcinoma of the colon: An unexpected diagnosis: A case report

“…Contrary to colonic adenocarcinomas, LCNECCs typically exhibit negativity for CK20 [ 10 ], such as in our case. However, isolated cases of CK20-positive LCNECCs have been reported, suggesting a potential common stem cell origin between LCNECCs and adenocarcinomas [ 11 ].…”

“…The ascending colon represents the predominant site common for LCNECCs [ 6 , 8 ], typically presenting with an average tumor size of 7.4 cm [4-11 cm] [ 9 ], Table 1 . Clinical presentation mirrors that of adenocarcinomas [ 10 ], with common symptoms including abdominal pain, constipation, melena, rectal bleeding, tenesmus and diarrhea [ 10 , 11 ]. Complications such as acute intestinal obstruction or colonic perforation may ensue [ 7 , 10 , 12 ], albeit rare cases may remain asymptomatic and be incidentally detected through screening with a fecal occult blood test [ 6 ].…”

An unexpected case of large cell neuroendocrine carcinoma of the colon: a case report

“…LCNECs are prognostically poor cancers due to both the aggressive nature of the malignancy itself and the high chance of metastasis at the point of diagnosis with a 1-year survival rate at approximately 10% and a median survival time of 5 to 11 months ( 5 , 7 ). There are not formally established universal treatment modalities for LCNECs given the highly invasive nature of the cancer ( 6 - 9 ).…”

“…For our patient, the novelty in his treatment and current outcomes are related to the finding of LCNEC incidentally and early prior to the rapid metastasis to additional organs indicated by other reports ( 3 ). In addition, previous reports also indicated a need for further research and data discussing the standardization of treatment for patients diagnosed with LCNECs ( 5 ). In lieu of this, our study highlights a potential standardized treatment modality via the combination of both ENETS and NANETS consensus guidelines with a minor change to replace cisplatin with carboplatin further emphasizing the novelty in our report ( 8 , 9 ).…”

“…Notably, LCNECs can resemble poorly differentiated adenocarcinomas; thus, it is critical to examine neuroendocrine markers to avoid diagnosis prolongation considering the poor prognosis and high metastatic potential ( 4 ). Histologically, high mitotic rates, large polygonal cells with coarse chromatin, as well as forming nesting, organoid, trabecular, rosette, and palisading patterns ( 5 ). In 2010, World Health Organization (WHO) classified neuroendocrine tumors into categories based on grade as indicated by the Ki-67 index ( 4 ).…”