Abstract：
UNASSIGNED: Large cell neuroendocrine carcinomas of the colon (LCNECC) are exceptionally rare, comprising only 0.2 % of all colonic carcinomas. Their diagnosis poses a significant challenge due to their propensity to mimic colonic adenocarcinomas. Typically diagnosed at advanced stages, LCNECCs carry a grim prognosis. Herein, we present a rare case of LCNECC and aim to elucidate its clinico-pathological characteristics.
METHODS: A 56-year-old female patient presented with complaints of constipation, abdominal pain, and weight loss. On physical examination, a sizable mass was palpable in the right flank. Colonoscopy revealed a polyp in the descending colon and a friable multinodular stenosing mass in the ascending colon. Microscopic examination of the biopsy from the ascending colon mass exhibited a poorly differentiated large cell carcinomatous proliferation with positivity for synaptophysin and CD56, along with a Ki-67 proliferation index of 50 %. The polyp in the descending colon was consistent with a low-grade dysplastic tubular adenoma. A diagnosis of LCNECC with synchronous low-grade dysplastic tubular adenoma was established. A right hemicoloctomy was performed. Final pathological examination confirmed LCNECC invading the muscularis propria, with lymph node metastases. The tumor was classified as pT2N1M0 (Stage III).
UNASSIGNED: LCNECCs often mimic adenocarcinomas clinically, endoscopically, and radiologically. Pathological examination is the key for diagnosis. An immunohistochemical study using neuroendocrine markers is imperative to prevent overlooking the diagnosis of LCNECC.
CONCLUSIONS: LCNECCs represent rare aggressive carcinomas. Their diagnosis might be challenging. A better knowledge of this rare entities would enable early diagnosis.
METHODS: A 56-year-old female patient presented with complaints of constipation, abdominal pain, and weight loss. On physical examination, a sizable mass was palpable in the right flank. Colonoscopy revealed a polyp in the descending colon and a friable multinodular stenosing mass in the ascending colon. Microscopic examination of the biopsy from the ascending colon mass exhibited a poorly differentiated large cell carcinomatous proliferation with positivity for synaptophysin and CD56, along with a Ki-67 proliferation index of 50 %. The polyp in the descending colon was consistent with a low-grade dysplastic tubular adenoma. A diagnosis of LCNECC with synchronous low-grade dysplastic tubular adenoma was established. A right hemicoloctomy was performed. Final pathological examination confirmed LCNECC invading the muscularis propria, with lymph node metastases. The tumor was classified as pT2N1M0 (Stage III).
UNASSIGNED: LCNECCs often mimic adenocarcinomas clinically, endoscopically, and radiologically. Pathological examination is the key for diagnosis. An immunohistochemical study using neuroendocrine markers is imperative to prevent overlooking the diagnosis of LCNECC.
CONCLUSIONS: LCNECCs represent rare aggressive carcinomas. Their diagnosis might be challenging. A better knowledge of this rare entities would enable early diagnosis.
摘要：
■结肠大细胞神经内分泌癌（LCNECC）非常罕见，仅占所有结肠癌的0.2%。由于它们模仿结肠腺癌的倾向，它们的诊断提出了重大挑战。通常在晚期诊断，LCNECCs预后严峻。在这里，我们介绍了一例罕见的LCNECC病例,旨在阐明其临床病理特征.
方法：一名56岁女性患者出现便秘，腹痛,和减肥。在体检时，右侧有相当大的肿块。结肠镜检查显示降结肠有息肉，升结肠有易碎的多结节性狭窄肿块。升结肠肿块活检的显微镜检查显示分化差的大细胞癌增殖，突触素和CD56阳性，Ki-67增殖指数为50％。降结肠中的息肉与低度发育不良的管状腺瘤一致。建立了LCNECC与同步低级别增生性管状腺瘤的诊断。进行了右半结肠切除术。最终病理检查证实LCNECC侵入固有肌层，淋巴结转移。肿瘤被分类为pT2N1M0(III期)。
■LCNECCs通常在临床上模拟腺癌，内窥镜,和放射学。病理检查是诊断的关键。使用神经内分泌标志物的免疫组织化学研究对于防止忽视LCNECC的诊断是必要的。
结论：LCNECCs代表罕见侵袭性癌。他们的诊断可能具有挑战性。更好地了解这种罕见的实体将能够进行早期诊断。
方法：一名56岁女性患者出现便秘，腹痛,和减肥。在体检时，右侧有相当大的肿块。结肠镜检查显示降结肠有息肉，升结肠有易碎的多结节性狭窄肿块。升结肠肿块活检的显微镜检查显示分化差的大细胞癌增殖，突触素和CD56阳性，Ki-67增殖指数为50％。降结肠中的息肉与低度发育不良的管状腺瘤一致。建立了LCNECC与同步低级别增生性管状腺瘤的诊断。进行了右半结肠切除术。最终病理检查证实LCNECC侵入固有肌层，淋巴结转移。肿瘤被分类为pT2N1M0(III期)。
■LCNECCs通常在临床上模拟腺癌，内窥镜,和放射学。病理检查是诊断的关键。使用神经内分泌标志物的免疫组织化学研究对于防止忽视LCNECC的诊断是必要的。
结论：LCNECCs代表罕见侵袭性癌。他们的诊断可能具有挑战性。更好地了解这种罕见的实体将能够进行早期诊断。
