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Clinicopathological effect of PLAG1 fusion genes in pleomorphic adenoma and carcinoma ex pleomorphic adenoma with special emphasis on histological features
Author(s) -
Asahina Miki,
Saito Tsuyoshi,
Hayashi Takuo,
Fukumura Yuki,
Mitani Keiko,
Yao Takashi
Publication year - 2019
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.13759
Subject(s) - myoepithelial cell , pathology , biology , fusion gene , carcinoma ex pleomorphic adenoma , adenoma , pleomorphic adenoma , parenchyma , carcinoma , salivary gland , immunohistochemistry , medicine , gene , biochemistry
Aims Pleomorphic adenoma gene 1 ( PLAG 1 ) rearrangement is well known in pleomorphic adenoma ( PA ), which is histologically characterised by admixed epithelial and mesenchymal components. Multiple fusion variants of PLAG 1 and HMGA 2 have been reported; currently, however, little is known regarding the clinicopathological impacts of these fusion types Methods and results We examined the PLAG 1‐ and HMGA 2‐ related fusion status in 105 PA s and 11 cases of carcinoma ex PA s ( CXPA ) arising from salivary glands and lacrimal glands to elucidate their correlation to the clinicopathological factors. Forty cases harboured PLAG 1 fusion genes: CTNNB 1– PLAG 1 in 22 cases, CHCHD 7– PLAG 1 in 14 cases and LIFR – PLAG 1 in four cases. Only two cases possessed HMGA 2 fusion genes. The mean age of LIFR – PLAG 1 ‐positive cases was significantly higher than that of CTNNB 1– PLAG 1 ‐ and CHCHD 7– PLAG 1 ‐positive cases ( P = 0.0358). PA s located in the submandibular gland demonstrated CTNNB 1– PLAG 1 fusion at a significantly higher rate than other fusions ( P = 0.0109). Histologically, PLAG 1 fusion‐positive cases exhibited chondroid formation and plasmacytoid features more commonly ( P = 0.043, P = 0.015, respectively) and myxoid abundant feature less frequently ( P = 0.031) than PLAG 1 fusion‐negative cases. For CXPA s, four CTNNB 1– PLAG 1 fusions were detected in two salivary duct carcinomas and two myoepithelial carcinomas. Ductal formation was observed frequently (90.9%) in residual PA . Conclusions The presence of PLAG 1 fusion was associated with specific histological features in PA . Detecting the PLAG 1 fusion gene and searching residual ductal formation in salivary gland malignant tumours with extensive hyalinisation could be useful for diagnosis.