Berho M, Blaustein A, Willis I, Sorace D, Suster S
Arkadi M. Rywlin Department of Pathology and Laboratory Medicine, Mount Sinai Medical Center, Miami, Florida 33140, USA.
Am J Clin Pathol. 1996 Jun;105(6):727-32. doi: 10.1093/ajcp/105.6.727.
Two cases are described of an unusual form of primary adenocarcinoma of the pancreas characterized histologically by their striking resemblance with a neuroendocrine neoplasm. The tumors were composed of a population of relatively small, uniform cells arranged in sheets admixed with small microglandular structures resulting in a cribriform pattern of growth. The tumor cells displayed scant cytoplasm with indistinct cell borders and round to oval nuclei with irregular clumping of chromatin and small, inconspicuous nucleoli. Immunohistochemical studies in both cases showed positivity of the neoplastic cells with CAM 5.2 antibodies and negative staining with a battery of neuroendocrine-related markers including chromogranin, NSE and synaptophysin, as well as with a variety of peptide hormones including insulin, glucagon, vasoactive intestinal polypeptide, gastrin and serotonin. Ultrastructural examination revealed a cohesive population of cells forming abortive glandular lumens lined by imperfectly formed microvilli and showing well-developed junctional complexes. No dense core neurosecretory granules or zymogen granules could be identified in any of the cells, supporting a ductal type of differentiation for these tumors. The main importance of recognizing this rare variant of pancreatic adenocarcinoma lies in avoiding misdiagnosis with other primary and metastatic neuroendocrine neoplasms of this organ. Immunohistochemical and ultrastructural examination will be of value in such cases for differential diagnosis.
本文描述了两例不寻常的原发性胰腺腺癌，其组织学特征与神经内分泌肿瘤极为相似。肿瘤由一群相对较小、形态一致的细胞组成，这些细胞呈片状排列，并混有小的微腺管结构，形成筛状生长模式。肿瘤细胞胞质稀少，细胞边界不清，核呈圆形至椭圆形，染色质不规则聚集，核仁小且不明显。两例病例的免疫组织化学研究均显示肿瘤细胞对CAM 5.2抗体呈阳性反应，而对一系列神经内分泌相关标志物（包括嗜铬粒蛋白、NSE和突触素）以及多种肽类激素（包括胰岛素、胰高血糖素、血管活性肠肽、胃泌素和5-羟色胺）呈阴性染色。超微结构检查显示一群相互黏附的细胞形成了发育不全的腺腔，腺腔内衬有发育不完善的微绒毛，并可见发育良好的连接复合体。在任何细胞中均未发现致密核心神经分泌颗粒或酶原颗粒，这支持了这些肿瘤为导管型分化。认识这种罕见的胰腺腺癌变异型的主要重要性在于避免与该器官的其他原发性和转移性神经内分泌肿瘤发生误诊。在这种情况下，免疫组织化学和超微结构检查对于鉴别诊断具有重要价值。
