背景:胃母细胞瘤是一种罕见的由上皮和梭形细胞成分组成的胃肿瘤。仅在5例报道的病例中鉴定了特征性的MALAT-GLI1融合基因。我们报告了一名年轻日本女性中具有MALAT1-GLI1融合基因的胃母细胞瘤的形态学特征。
方法:一名29岁的日本妇女因上腹痛到岩手医科大学医院就诊。计算机断层扫描显示,涉及胃窦的扩张性病变中有肿瘤。组织学上,我们观察到由上皮细胞和梭形细胞成分组成的双相形态。上皮成分表现为狭缝状腺体结构,具有管状或玫瑰花状分化。梭形细胞成分由短的梭形卵圆形细胞组成。免疫组织化学(IHC)分析显示梭形细胞成分对波形蛋白呈阳性,CD10、CD56、GLI1和HDAC2,局部PD-L1阳性。上皮成分对CKAE1/AE3,CAM5.2和CK7呈阳性,对CK20和EMA呈阴性。这两个组成部分对KIT都是阴性的,CD34,DOG1,SMA,desmin,S100蛋白,嗜铬粒蛋白A,突触素,CDX2和SS18-SSX。分子检测MALAT-GLI1融合基因。
结论:我们报告了该病例的以下新发现:(i)胃肿瘤在胚胎期模拟胃肠道间质;(ii)在胃母细胞瘤的梭形细胞成分中观察到PD-L1和HDAC2的核表达。我们推测组蛋白去乙酰化酶(HDAC)抑制剂可能为胃母细胞瘤提供有希望的治疗选择。
BACKGROUND: Gastroblastoma is a rare gastric tumor composed of epithelial and spindle cell components. The characteristic MALAT-GLI1 fusion gene has only been identified in 5 reported cases. We report the morphological characterization of gastroblastoma with the MALAT1-GLI1 fusion gene in a young Japanese woman.
METHODS: A 29-year-old Japanese woman visited Iwate Medical University Hospital with upper abdominal pain. Computed tomography revealed a tumor in expansive lesions involving the gastric antrum. Histologically, we observed a biphasic morphology composed of epithelial and spindle cell components. The epithelial components appeared as slit-like glandular structures with tubular or rosette-like differentiation. The spindle cell components consisted of short spindle-shaped oval cells. Immunohistochemical (IHC) analysis revealed that the spindle cell component was positive for vimentin, CD10, CD56, GLI1, and HDAC2, and focally positive for PD-L1. The epithelial component was positive for CK AE1/AE3, CAM5.2, and CK7, and negative for CK20 and EMA. Both components were negative for KIT, CD34, DOG1, SMA, desmin, S100 protein, chromogranin A, synaptophysin, CDX2, and SS18-SSX. The MALAT-GLI1 fusion gene was detected molecularly.
CONCLUSIONS: We report the following new findings with this
case: (i) gastric tumors mimic the gastrointestinal mesenchyme in the embryonic period; (ii) nuclear expression of PD-L1 and HDAC2 were observed in the spindle cell component of a gastroblastoma. We speculate that histone deacetylase (HDAC) inhibitors may offer a promising treatment option for gastroblastoma.