Department of General Surgery, Colorectal Surgery Section, King Fahad Specialist Hospital, Dammam, Saudi Arabia.
College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
Am J Case Rep. 2021 Apr 15;22:e929099. doi: 10.12659/AJCR.929099.
BACKGROUND Metastatic mixed adeno-neuroendocrine carcinoma (MANEC) is a rare malignancy. It is characterized by the presence of both neuroendocrine and epithelial components, each of which constitute at least 30% of the lesion to establish the diagnosis. CASE REPORT A 48-year-old man presented with a 1-month history of right upper-quadrant pain and unintentional weight loss of 18 kg. He was also complaining of constipation and fatigue for 6 days. The initial diagnosis from a referring hospital was colon cancer with liver metastasis based on a computed tomography (CT) scan of the chest, abdomen and pelvis. After re-evaluation at our hospital, the scan revealed multiple peritoneal deposits in addition to the previously reported findings. A colonoscopy and biopsy were performed, after which the histopathological examination demonstrated a mixed poorly differentiated large cell neuroendocrine carcinoma and adenocarcinoma. Based on the imaging and histopathology reports, he was diagnosed with a poorly differentiated MANEC of the colon with liver metastasis and multiple peritoneal deposits. His lesions were deemed unresectable, and he was referred to the oncology department for palliative care. There he received a total of 9 cycles of cisplatin and etoposide for 8 months. His CT scan showed a regression of the primary tumor indicating a good response to chemotherapy. The patient is still following up with his medical oncologist. CONCLUSIONS Although it is rare, MANEC is a complex neoplasm that requires a high index of suspicion to diagnose due to its nonspecific presentation. It is confirmed through histopathology and immunohistochemistry of the tumor biopsy. Imaging is performed for staging, with most patients presenting at advanced stages with metastases. The only curative option is complete surgical resection of both the primary and metastatic lesion. Many cases, however, are regarded as unresectable and are referred for palliative treatment.
转移性混合性腺神经内分泌癌（MANEC）是一种罕见的恶性肿瘤。其特征是同时存在神经内分泌和上皮成分，每种成分至少占病变的 30%，以确立诊断。
一名 48 岁男性，因右上象限疼痛和 1 个月体重减轻 18 公斤就诊。他还抱怨 6 天来便秘和疲劳。最初在一家转诊医院的诊断是根据胸部、腹部和骨盆的计算机断层扫描（CT）结果，认为是结肠癌伴肝转移。在我院重新评估后，扫描结果显示除了先前报告的发现外，还有多个腹膜沉积物。进行了结肠镜检查和活检，组织病理学检查显示混合低分化大细胞神经内分泌癌和腺癌。根据影像学和组织病理学报告，他被诊断为结肠癌伴肝转移和多个腹膜沉积物的低分化混合 MANEC。他的病变被认为不可切除，他被转介到肿瘤科进行姑息治疗。在那里，他接受了总共 9 个周期的顺铂和依托泊苷治疗，持续了 8 个月。他的 CT 扫描显示原发性肿瘤消退，表明对化疗有良好的反应。患者仍在接受他的肿瘤内科医生的随访。
尽管罕见，但 MANEC 是一种复杂的肿瘤，由于其非特异性表现，需要高度怀疑才能诊断。它通过肿瘤活检的组织病理学和免疫组织化学来确认。影像学用于分期，大多数患者在晚期出现转移。唯一的治愈选择是完全切除原发性和转移性病变。然而，许多病例被认为不可切除，需要进行姑息治疗。
