• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.81-93
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• 2006

Obstructive sialadenitis is one of common disease in salivary gland, and most common histologic features are loss of acinar cell and ductal dilatation associated with fibrosis, and infiltration of inflammatory cells. Although many experimental studies has been accomplished for the salivary acinar cell change in obstructive salivary gland disease, studies for myoepithelial cell were deficient. This study is designed for salivary gland tissue change, especially myoepithelial cell when nonspecific chronic sialadenitis or salivary duct injury by duct obstruction or cut can be occurred that is common encounted clinically. After ligation and cutting of submandibular gland of rabbit, groups of aminmal were sacrificed at 1, 2, 4 weeks postoperatively, submandibular gland were removed. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining with ${\alpha}$-smooth muscle actin, characteristics of myoepithelial cell were examined. With transmission electron microscopy, ultrastructure of myoepithelial cell were examined for distribution and ultrastructure of myoepithelial cell. The results were obtained as follows: 1. In the histopathologic evaluation, ligation and cutting group of 1 week, linkage of myoepithelial cell associated with acinar atrophy and degeneration were disappeared in both group. 2. More prominent squamous metaplasia was seen in acinar cells of ligation group of 2 weeks experimental rabbit than cutting group. 3. Acinar cells are nearly disappeared in both ligation and cutting group of 4 weeks, and myoepithelial cell also disappeared associated with acinar cell atrophy, and duct-like structure composed by squamous cells by squamous metaplasia in acinar cells were distributed. 4. In immunohistochemical study, both ligation and cutting group ${\alpha}$-SMA distribution were diminished at 1 week experimental rabbits, but myoepithelial cell was more diminished in ligation group than cutting group, which were distributed around cells of squamous metaplasia. 5. Nuclear condensation, chromosome margination, and cytoplasmic vaculoation were appeared in myoepithelial cell of both cutting and ligation group after 1 week with transmission electron microscopy. But degenerative substance were seen in cytoplasm of myoepithelial cell of ligation group of 4 weeks. From the results obtained in this study, atrophy and degeneration of myoepithelial cell was more prominent in duct ligation group than duct cutting group, and myoepithelial cells were seen around cells squamous metaplasia of acinar cell.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.1-12
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• 2006

Pleomorphic adenoma is the most common benign tumor in salivary glands, and occurred in frequency of 60% in parotid gland tumors, and 50% in submandibular gland tumors, and 25% in sublingual gland tumors. Histopathologically, pleomorphic adenoma is composed of epithelial cells and mesenchymal tissues, and called 'mixed tumor' because of morphological divergency. The cell structures of luminal area are composed of polyhedral and cuboidal secretory epithelial cells and modified myoepithelial cells around it, and mesenchymal tissue is composed of some myoepithelial cells and stromal tissue. In stromal tissue, myxoid change, chondroid change, or hyalinization can be seen even if bone tissue. In many studies, tumor cells of pleomorphic adenoma containing modified myoepithelial cell participate in synthesis of glycosaminoglycans. In this study, tissue sample of pleomorphic adenoma of human salivary gland were obtained from 20 surgical specimens, and all specimens were routinely fixed in 10% formalin and embedded. Serial 4-8${\mu}m$ thick sections were cut from paraffin blocks. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining, characteristics of glycosaminoglycan were observed. And, for biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and immuno-blot analysis were carried out. With transmission electromicroscopy, tumor cells and biologic behavior of pleomorphic adenoma were observed with distribution and expression of glycosaminoglycan in tumor cells, The results were obtained as follows: 1. In immunohistochemical study, chondroitin 4-sulfate is highly postively stained in myxoid stromal tissue, and chondroitin 6-sulfate is highly positively stained in chondroid mesenchymal tissue, both glycosaminoglycans are positively stained in non-luminal cell of ductal area. 2. Dermatan sulfate and keratan sulfate is positively stained in periductal non-luminal tumor cells. 3. In immunohistochemical study, heparan sulfate is weakly stained in luminal cells and non-luminal cells around duct, and chondroid mesenchymal tissue. 4. In transmission electromicroscopic view, the tumor cells are composed of modified myoepithelial cells, and contain many microfilaments and well developed rough endoplasmic reticulum. 5. In Immuno-Blot analysis, the expression of glycosaminoglycans is expressed mostly in chondroitin 6-sulfate and chondroitin 4-sulfate. From the results obtained in this study, tumor cells of pleomorphic adenoma are composed of modified myoepithelial cells, and glycosaminoglycans of chondroitin 4-sulfate and chondroitin 6-sulfate mostly participate in the development of pleomorphic adenoma, but dermatan sulfate, keratan sulfate and heparan sulfate glycosaminoglycans were expressed variably.