1. Recurrent rearrangements of the PLAG1 and HMGA2 genes in lacrimal gland pleomorphic adenoma and carcinoma ex pleomorphic adenoma.
- Author
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Andreasen S, von Holstein SL, Homøe P, and Heegaard S
- Subjects
- Adenocarcinoma metabolism, Adenocarcinoma pathology, Adenoma, Pleomorphic metabolism, Adenoma, Pleomorphic pathology, Adolescent, Adult, Aged, Aged, 80 and over, Biomarkers, Tumor, DNA-Binding Proteins metabolism, Eye Neoplasms metabolism, Eye Neoplasms pathology, Female, Genes, Neoplasm genetics, HMGA2 Protein metabolism, Humans, Immunohistochemistry, In Situ Hybridization, Fluorescence, Lacrimal Apparatus Diseases metabolism, Lacrimal Apparatus Diseases pathology, Male, Middle Aged, Recurrence, Retrospective Studies, Adenocarcinoma genetics, Adenoma, Pleomorphic genetics, DNA-Binding Proteins genetics, Eye Neoplasms genetics, Gene Rearrangement, HMGA2 Protein genetics, Lacrimal Apparatus Diseases genetics
- Abstract
Purpose: Lacrimal gland tumours constitute a wide spectrum of neoplastic lesions that are histologically similar to tumours of the salivary gland. In the salivary gland, pleomorphic adenoma (PA) is frequently characterized by recurrent chromosomal rearrangements of the PLAG1 and HMGA2 genes, a genetic feature retained in carcinoma ex pleomorphic adenoma (ca-ex-PA) that makes it possible to distinguish ca-ex-PA from de novo carcinomas. However, whether PLAG1 and HMGA2 gene rearrangements are found in lacrimal gland PA and ca-ex-PA is not known., Methods: Twenty-one lacrimal gland PAs and four ca-ex-PAs were retrospectively reviewed and subjected to break-apart fluorescence in situ hybridization (FISH) for rearrangements of the PLAG1 gene. Cases without PLAG1 abnormalities were subjected to HMGA2 break-apart FISH. Immunohistochemical staining for PLAG1 and HMGA2 protein was performed and correlated with gene status., Results: Sixteen of 21 PAs showed rearrangement of PLAG1 and were all positive for PLAG1 protein. Two of the remaining five PAs showed rearrangement of HMGA2 and were the only cases positive for HMGA2 with immunohistochemistry. The three FISH-negative PAs expressed PLAG1 protein. All four ca-ex-PAs showed rearrangement of PLAG1 and expressed PLAG1 protein. None of the de novo carcinomas showed rearrangement of either of the two genes or expression of the two proteins., Conclusion: Rearrangement of PLAG1 and HMGA2 and expression of the corresponding proteins are frequent and specific findings in lacrimal gland PA and ca-ex-PA. The mechanism for PLAG1 overexpression in FISH-negative PAs is yet to be clarified., (© 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)
- Published
- 2018
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