Abstract：
Amphicrine carcinomas are epithelial neoplasms composed of cells with co-existing exocrine-neuroendocrine phenotype and are challenging lesions from both diagnostic and therapeutic perspectives.Here, we report the case of a 63-year-old male patient with a gastric nodule that was endoscopically biopsied, revealing histological features of a type 3 well-differentiated gastric neuroendocrine tumor (NET). At imaging, the lesion was single and limited to the stomach, but did not present In-111Octreotide uptake, despite SSTR2A immunohistochemical expression. The patient underwent a wedge resection of the gastric wall, with a final pathological diagnosis of amphicrine carcinoma with pancreatic acinar cell and neuroendocrine features (pT1b). Predictive immunohistochemistry showed microsatellite stability and negative HER2 status. Hotspot targeted deep sequencing of 57 genes showed no somatic mutation, in agreement with the low mutational burden reported for gastric amphicrine carcinomas. Due to a low stage of the tumor and the poor performance status of the patient, no additional oncological treatment was administered. The patient was disease-free after 18 months.This unusual case highlights the importance of considering amphicrine carcinoma in the diagnostic work-up of gastric type 3 NET. This can be done by including in the immunohistochemical panel non-neuroendocrine markers, such as the pancreatic acinar cell and glandular ones. Correct pathological diagnosis is pivotal to determine the appropriate staging (NET vs exocrine one) for surgical and oncological management.
摘要：
Amphicrine癌是由具有共存的外分泌神经内分泌表型的细胞组成的上皮肿瘤，从诊断和治疗的角度都具有挑战性。这里,我们报告了一个63岁的男性患者，患有胃结节，进行了内窥镜活检，揭示3型高分化胃神经内分泌肿瘤（NET）的组织学特征。在成像时，病变是单一的，仅限于胃，但不存在In-111奥曲肽摄取，尽管SSTR2A免疫组织化学表达。病人做了胃壁楔形切除术,最终病理诊断为具有胰腺腺泡细胞和神经内分泌特征（pT1b）的苯丙胺癌。预测免疫组织化学显示微卫星稳定性和阴性HER2状态。57个基因的热点靶向深度测序显示无体细胞突变,与胃苯丙胺癌报道的低突变负担一致。由于肿瘤的低阶段和患者的不良表现状态，没有进行额外的肿瘤治疗.患者在18个月后无病。这种不寻常的情况凸显了在3型胃NET的诊断工作中考虑苯丙胺癌的重要性。这可以通过在免疫组织化学组中包括非神经内分泌标记来完成，如胰腺腺泡细胞和腺泡细胞。正确的病理诊断对于确定手术和肿瘤治疗的适当分期（NETvs外分泌者）至关重要。
