Craver Randall D, Fonseca Paula, Carr Ronald
Department of Pathology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
Pediatr Dev Pathol. 2010 Sep-Oct;13(5):348-53. doi: 10.2350/09-05-0654-OA.1. Epub 2010 Jan 7.
There are conflicting reports regarding the relative frequency of benign and malignant epithelial salivary gland tumors in children. There are only a few reports of the cytogenetic abnormalities in the pleomorphic adenomas (PA) that arise in children, and even less information regarding the pleomorphic adenoma gene 1 (PLAG1) and high motility group A2 (HMGA2 ) histochemical staining in PAs, or their correlation with histologic types (stromal vs epithelial predominance). A retrospective 14 year review of epithelial salivary gland tumors encountered at a children's hospital identified 13 tumors: 12 PAs and 1 acinic cell carcinoma (ACC). No mucoepidermoid carcinomas were identified. Tumors arose in the parotid (7) and other sites (2 submandibular, 4 minor). Ten PAs in our cohort had cytogenetic studies. Four were normal, 5 involved 8q12, and 1 involved 12q13. Immunohistochemistry identified an additional 2 PAs with PLAG1 staining, and 5 additional PAs with HMGA2 staining. One tumor with ins(18;8)(q21.1;q12q22.2) had no PLAG1 staining, but stained with HMGA2. This ins(18;8) may not have involved the PLAG1 gene. There was no demonstrable correlation of 8q12/PLAG1 staining or 12q13/HMGA2 staining with histologic type. Thus we found abnormalities in either 8q12/PLAG1 staining or 12q13/HMGA2 staining in all PAs. The HMGA2 staining in 50% of PAs suggests that it may be more frequently involved in PAs than previously thought based on cytogenetic studies, at least in children.
关于儿童唾液腺上皮性良恶性肿瘤的相对发病率，报告结果相互矛盾。关于儿童多形性腺瘤（PA）细胞遗传学异常的报告仅有几例，而关于多形性腺瘤基因1（PLAG1）和高迁移率族蛋白A2（HMGA2）在多形性腺瘤中的组织化学染色，或它们与组织学类型（间质型与上皮型为主）相关性的信息更少。一家儿童医院对14年间遇到的唾液腺上皮性肿瘤进行回顾性研究，共确定了13例肿瘤：12例多形性腺瘤和1例腺泡细胞癌（ACC）。未发现黏液表皮样癌。肿瘤发生于腮腺（7例）和其他部位（2例颌下腺、4例小唾液腺）。我们队列中的10例多形性腺瘤进行了细胞遗传学研究。4例正常，5例涉及8q12，1例涉及12q13。免疫组织化学鉴定出另外2例多形性腺瘤有PLAG1染色，5例多形性腺瘤有HMGA2染色。1例具有ins(18;8)(q21.1;q12q22.2)的肿瘤没有PLAG1染色，但有HMGA2染色。这种ins(18;8)可能未涉及PLAG1基因。8q12/PLAG1染色或12q13/HMGA2染色与组织学类型之间没有明显相关性。因此，我们发现所有多形性腺瘤中均存在8q12/PLAG1染色或12q13/HMGA2染色异常。50%的多形性腺瘤有HMGA2染色，这表明至少在儿童中，它可能比基于细胞遗传学研究之前认为的更频繁地参与多形性腺瘤的发生。
