Enescu Anca Stefania, Mărgăritescu C L, Crăiţoiu Monica Mihaela, Enescu Aurelia, Crăiţoiu Ştefania
Department of Pathology, Faculty of Dentistry, University of Medicine and Pharmacy of Craiova, Romania;
Rom J Morphol Embryol. 2013;54(4):969-76.
Pleomorphic adenoma is the most common salivary gland tumor with annual incidence of 2-3.5/100 000 in population. The histogenesis of salivary gland pleomorphic adenoma is still unclear. One concept sustains the existence of an epithelial-mesenchymal transitions (EMT) process in pleomorphic adenomas by which neoplastic epithelial cells transdifferentiate into mesenchymal cells and leading to tissue heterogeneity from this salivary gland neoplasia. Here we investigate by immunohistochemistry the expression of growth differentiation factor 5 (GDF5) and aggrecan in 15 cases of salivary gland pleomorphic adenomas. We found that both markers were present in normal salivary gland, mainly in the cells that line striated and intercalated ducts suggesting their involvement in the morphogenesis of this duct system. A constant positive reactivity for both markers was recorded in transition regions from tubular proliferative units to myxoid areas suggesting the involvement of an EMT process during the tumorigenesis of such salivary gland neoplasia. Also, both markers may be implicated in the transdifferentiation of neoplastic myoepithelial cells from the myxoid zones to lacuna cells of adjacent chondroid areas completing the morphology of this salivary gland tumor.
多形性腺瘤是最常见的唾液腺肿瘤，人群年发病率为2-3.5/10万。唾液腺多形性腺瘤的组织发生仍不清楚。一种观点认为多形性腺瘤中存在上皮-间质转化（EMT）过程，通过该过程肿瘤上皮细胞转分化为间充质细胞，并导致这种唾液腺肿瘤出现组织异质性。在此，我们通过免疫组织化学研究了15例唾液腺多形性腺瘤中生长分化因子5（GDF5）和聚集蛋白聚糖的表达。我们发现这两种标志物在正常唾液腺中均有表达，主要存在于纹状管和闰管内衬细胞中，提示它们参与了该导管系统的形态发生。在从管状增生单位到黏液样区域的过渡区，两种标志物均呈现持续阳性反应，提示在这种唾液腺肿瘤的发生过程中涉及EMT过程。此外，这两种标志物可能还参与了肿瘤性肌上皮细胞从黏液样区域向相邻软骨样区域陷窝细胞的转分化，从而完善了这种唾液腺肿瘤的形态。
