摘要：

目的 报告首例脑转移性混合性腺神经内分泌癌的临床病理学特征，探讨诊断与鉴别诊断要点和预后影响因素。方法与结果 男性患者，35 岁。临床表现为头痛、呕吐，CT 显示右侧颞叶占位性病变。术中可见肿瘤直径约3 cm，边界欠清晰，质地软韧，血供丰富。肿瘤由大小较一致的小圆形细胞构成，局部肿瘤细胞围绕小血管形成“菊形团”样或乳头样结构，核分裂象活跃，与周围脑组织界限不清；肿瘤细胞弥漫性表达突触素和CD56，不表达胶质纤维酸性蛋白、广谱细胞角蛋白、CD3、CD20、波形蛋白、白细胞共同抗原、甲状腺转录因子-1、S-100 蛋白、神经微丝蛋白、巢蛋白、细胞角蛋白（CK）5/6、CK8/18 和CD99，Ki-67 抗原标记指数约为62%。外院行乙状结肠肠镜检查发现肿物，组织学呈明显双相性，由大小一致的小圆形细胞和低至中度分化的腺癌细胞构成，二者界限清晰，无移行。小圆形肿瘤细胞弥漫性表达突触素和CD56，不表达广谱细胞角蛋白；腺癌细胞弥漫性表达广谱细胞角蛋白，不表达突触素和CD56。结论 混合性腺神经内分泌癌为2010 年世界卫生组织命名和定义的肿瘤，发生脑转移者尚未见诸报道，明确诊断需依靠临床病史、组织形态学特征和免疫组织化学表型。

关键词: 腺癌, 癌, 神经内分泌, 中枢神经系统, 结肠, 乙状, 肿瘤转移, 免疫组织化学, 病理学

Abstract:

Objective  To study clinicopathological features, diagnosis, differential diagnosis and prognosis of mixed adenoneuroendocrine carcinoma (MANEC).  Methods  One case of MANEC with brain metastasis was reported focusing on the following aspects: clinical manifestations, histopathological features and immunophenotypes, and the relevant literatures were reviewed.  Results  A 35-year-old male presented headache and vomiting, and his head CT scan showed a lesion located in the right temporal lobe. The tumor was detected after separating the cerebral cortex during the surgery. The tumor diameter was 3 cm. The tumor was soft and rubbery with ill-defined margins, and rich in blood supply. Under optical microscopy, the tumor was consisted of small round cells of the same size, with focal tumor cells arranged around blood vessels in a pseudorosette manner or papillary manner with brisk mitotic activity. The boundary between tumor and brain tissue was ill-defined. By using immunohistochemical staining, the tumor cells were diffusely positive for synaptophysin (Syn) and CD56, and negative for glial fibrillary acidic protein (GFAP), pan cytokeratin (PCK), CD3, CD20, vimentin (Vim), leukocyte common antigen (LCA), thyroid transcription factor-1 (TTF-1), S-100 protein (S-100), neurofilament (NF), nestin (Nes), CK5/6, CK8/18 and CD99. Ki-67 labeling index was about 62% . Sigmoidoscopy was performed later in another hospital and showed a mass in the patient's colon. The colon tumor was biphasic in appearance, and was consisted of two distinct components: isomorphic small round cells and low-middle differentiated adenocarcinoma cells. The small round tumor cells were diffusely positive for Syn and CD56, and negative for PCK. The adenocarcinoma cells showed opposite results.  Conclusions  MANEC is a rare tumor, which is defined in 2010 by WHO Classification of Digestive, and to the best of our knowledge, MANEC of the colon with brain metastasis has never been described. Therefore, this paper reports the first case of MANEC of the colon with brain metastasis. Definite diagnosis could be made by medical history, typical histopathological characteristics and immunohistochemical expressions.

Key words: Adenocarcinoma, Carcinoma, neuroendocrine, Central nervous system, Colon, sigmoid, Neoplasm metastasis, Immunohistochemistry, Pathology