Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Nov 15, 2022; 14(11): 2266-2272
Published online Nov 15, 2022. doi: 10.4251/wjgo.v14.i11.2266
Silent advanced large cell neuroendocrine carcinoma with synchronous adenocarcinoma of the colon: A case report
Hyeon Seok Baek, Sang Wook Kim, Soo Teik Lee, Ho Sung Park, Seung Young Seo
Hyeon Seok Baek, Sang Wook Kim, Soo Teik Lee, Seung Young Seo, Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju-si 56445, Jeollabuk-do, South Korea
Ho Sung Park, Department of Pathology, Jeonbuk National University Medical School, Jeonju-si 56445, Jeollabuk-do, South Korea
Author contributions: Baek HS analyzed clinical data and drafted the manuscript; Lee ST, Kim SW, Seo SY advised and reviewed the manuscript; Park HS performed the pathologic review.
Informed consent statement: Informed written consent was obtained from the patient regarding the publication of this report and accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
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Corresponding author: Seung Young Seo, MD, PhD, Professor, Department of Internal Medicine, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, 20 Geonji-ro, Deokjin-gu, Jeonju-si 56445, Jeollabuk-do, South Korea. bear7905@jbnu.ac.kr
Received: July 22, 2022
Peer-review started: July 22, 2022
First decision: August 19, 2022
Revised: August 31, 2022
Accepted: October 12, 2022
Article in press: October 12, 2022
Published online: November 15, 2022
Processing time: 116 Days and 8.4 Hours
Abstract
BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) accounts for about 0.25% of colorectal cancer patients. Furthermore, synchronous LCNEC and adenocarcinoma coexistence in the colon is very rare. LCNEC are usually aggressive and have a poor prognosis. Usually, colorectal LCNEC patients complain of abdominal symptoms such as pain, diarrhea or hematochezia because it is often diagnosed as an advanced disease that accompanies metastatic lesions.

CASE SUMMARY

We describe a case of relatively asymptomatic synchronous LCNEC and colon adenocarcinoma. A 62-year-old male patient visited our hospital due to anemia detected by a local health check-up. He did not complain of melena, hematochezia or abdominal pain. Physical examination was unremarkable and his abdomen was soft, nontender and nondistended with no palpable mass. Laboratory tests revealed anemia with hemoglobin 5.1 g/dL. Colonoscopy revealed an ulcerofungating lesion in the ascending colon and about a 1.5 cm-sized large sessile polyp in the sigmoid colon. Endoscopic biopsy of the ascending colon lesion revealed the ulcerofungating mass that was LCNEC and endoscopic mucosal resection at the sigmoid colon lesion showed a large polypoid lesion that was adenocarcinoma. Multiple liver, lung, bone and lymph nodes metastasis was found on chest/abdominal computed tomography and positron emission tomography. The patient was diagnosed with advanced colorectal LCNEC with liver, lung, bone and lymph node metastasis (stage IV) and synchronous colonic adenocarcinoma metastasis. In this case, no specific symptom except anemia was observed despite the multiple metastases. The patient refused systemic chemotherapy and was discharged after transfusion.

CONCLUSION

We report a case of silent LCNEC of the colon despite the advanced state and synchronous adenocarcinoma.

Keywords: Large cell neuroendocrine carcinoma; Colon; Synchronous; Adenocarcinoma; Case report

Core Tip: Large cell neuroendocrine carcinoma (LCNEC) account for about 0.25% of colorectal cancer patients. Furthermore, LCNEC with synchronous or metachronous adenocarcinoma in the colon has been reported in only a few cases. We report the diagnostic experience of a 62-year-old patient with advanced LCNEC in the colon and synchronous adenocarcinoma metastasis but no definitive symptoms except anemia. We suggest the possibility of an association between the two types of primary colon cancer. Therefore, if a patients diagnosed with LCNEC in the colon, appropriate screening tests are required. Further studies are needed on the pathogenesis of the two primary cancers.