Danner D B, Hruban R H, Pitt H A, Hayashi R, Griffin C A, Perlman E J
Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland.
Mod Pathol. 1994 Feb;7(2):200-4.
Peripheral primitive neuroectodermal tumors (PNETs) are extra cranial primitive small round blue cell tumors showing histologic, immunohistochemical or electron microscopic evidence of neuroectodermal differentiation. They are most commonly encountered in the soft tissue or bone in children and young adults. We report an unusual case of a PNET arising in the pancreas. A 17-yr-old male presented with a pancreatic mass and underwent a pancreatoduodenectomy. Histologically, the neoplasm was composed of sheets of small round cells that stained for cytokeratin, neuron specific enolase, and 12E7 but not muscle specific action, desmin, common leukocyte antigen, chromogranin, synaptophysin, or other islet cell markers. The diagnosis of PNET in this unusual location was confirmed by cytogenetic analysis which showed the chromosomal translocation characteristics of PNETs, t(11;12)(q24;q12). This case highlights the difficulty in the diagnosis of PNET when it is present in visceral organs where other neuroendocrine neoplasms and adenocarcinomas are more common.
外周原始神经外胚层肿瘤（PNETs）是颅外原始小圆形蓝细胞肿瘤，显示出神经外胚层分化的组织学、免疫组织化学或电子显微镜证据。它们最常见于儿童和年轻人的软组织或骨骼中。我们报告了一例罕见的胰腺发生的PNET病例。一名17岁男性因胰腺肿块就诊并接受了胰十二指肠切除术。组织学上，肿瘤由成片的小圆形细胞组成，这些细胞对细胞角蛋白、神经元特异性烯醇化酶和12E7呈阳性染色，但对肌肉特异性肌动蛋白、结蛋白、共同白细胞抗原、嗜铬粒蛋白、突触素或其他胰岛细胞标志物呈阴性染色。通过细胞遗传学分析证实了这个不寻常部位的PNET诊断，该分析显示了PNET的染色体易位特征，即t(11;12)(q24;q12)。该病例凸显了PNET出现在内脏器官时诊断的困难，因为在内脏器官中其他神经内分泌肿瘤和腺癌更为常见。
