TAKAHASHI, H., FUJITA, S., TSUDA, N., TEZUKA, F. and OKABE, H.
Immunohistochemical Demonstration of α1-Antichymotrypsin and α1-Antitrypsin in Salivary Gland Pleomorphic Adenomas of Children. Tohoku J. Exp. Med., 1990,
162 (1), 79-93-Twenty-five benign pleomorphic adenomas of salivary glands in children were studied with immunohistochemical techniques in order to characterize the cell types comprising the epithelial and so-called “mesenchymal” regions of the tumors. The antisera against α
1-antichymotrypsin (α
1-ACT) and α
1-antitrypsin (α
1-AT) were used to stain in normal salivary gland tissue as well as in pleomorphic adenoma. In normal salivary glands, α
1-ACT was localized to the intercalated duct and serous acinar cells. On the other hand, there was positive staining for α
1-AT in the intercalated and striated duct cells. Twenty-five cases (100%) of pleomorphic adenomas in children displayed positivity to α
1-ACT staining and 22 cases (88%) showed a positive staining for α
1-AT. α
1-ACT staining was particularly intense in chondrocyte-like cells of 20 cases (80%), in inner tubular cells of 16 (64%) and cyst-lining cells of 12 (52%). The limited number of tumor cells which were called plasmatoid or hyaline cells and squamous epithelial cells, were positive for α
1-ACT. None of the outer tubular cells and hyalinous material was positively stained for α
1-ACT. A strong positive reaction for α
1-AT was observed in chondrocyte-like cells of 15 cases (60%). Inner tubular cells were positive for α
1-AT in 12 cases (48%), plasmatoid or hyaline cells in 10 (40%) and cyst-lining cells in 8 (35%). Squamous epithelial cells, clear cells, secretory product and hyalinous material were positive for α
1-AT in some cases. Chondroid matrix and myxoid stroma had no reaction with both antibodies. The biological role of α
1-ACT and α
1-AT with a wide immunohistochemical distribution in pleomorphic adenomas of children may be associated with a self regulating mechanism which inhibits degradation by tissue proteinases.
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