Agrawal Tanupriya, Blau Adam J, Chwals Walter J, Tischler Arthur S
Departments of Pathology and Laboratory Medicine, Tufts Medical Center, Boston, MA, USA.
Department of Surgery, Tufts Medical Center, Boston, MA, USA.
Endocr Pathol. 2016 Mar;27(1):21-4. doi: 10.1007/s12022-015-9393-4.
Mediastinal teratomas with elements of mature pancreatic tissue are rare. Only a very few cases of pancreatic tissue with nesidioblastosis in teratoma have been reported. Here, we report a case of a 12-year-old male who presented with pleural effusion and was revealed to have a large anterior mediastinal mass. Biopsy of the mass revealed benign mature teratoma. After biopsy, the teratoma ruptured into the right thoracic cavity. It was then excised and sent to pathology for further evaluation. Preoperatively, there was no evidence of hyperinsulinemia or hypoglycemia. Postoperatively, there was no change in blood glucose levels. Histologically, the mass showed large areas of mature pancreatic tissue flanking a small intestine-like structure. Numerous endocrine cell islets, poorly defined groups of neuroendocrine cells and ductular-insular complexes characteristic of nesidioblastosis were dispersed in the exocrine pancreatic parenchyma. In addition, other parts of the tumor containing keratinizing squamous epithelium with cutaneous adnexal glands, small intestine, and bronchus including cartilage and respiratory epithelium were observed. Some islets contained two or more cell types while others were monophenotypic. Immunohistochemical staining showed pronounced expression of pancreatic polypeptide, moderate expression of somatostatin and insulin and nearly complete absence of glucagon-containing cells. The selective deletion of glucagon might hold clues to an important regulatory mechanism in pancreatic development.
含有成熟胰腺组织成分的纵隔畸胎瘤很罕见。仅有极少数畸胎瘤中存在胰岛母细胞增生性胰腺组织的病例报道。在此，我们报告一例12岁男性患者，其因胸腔积液就诊，检查发现前纵隔有一巨大肿块。肿块活检显示为良性成熟畸胎瘤。活检后，畸胎瘤破裂进入右侧胸腔。随后将其切除并送病理进一步评估。术前，无高胰岛素血症或低血糖的证据。术后，血糖水平无变化。组织学上，肿块显示大片成熟胰腺组织围绕着一个小肠样结构。大量内分泌细胞胰岛、界限不清的神经内分泌细胞群以及胰岛母细胞增生特征性的导管 - 胰岛复合体散在于外分泌胰腺实质中。此外，肿瘤的其他部分含有角化鳞状上皮伴皮肤附属器、小肠以及包括软骨和呼吸上皮的支气管。一些胰岛含有两种或更多种细胞类型，而其他的则为单表型。免疫组化染色显示胰多肽表达明显，生长抑素和胰岛素表达中等，几乎完全没有含胰高血糖素的细胞。胰高血糖素的选择性缺失可能为胰腺发育中的重要调节机制提供线索。
