First insights into the molecular basis of pleomorphic adenomas of the salivary glands

• Published in: Advances in dental research Vol. 14; no. 1; pp. 81 - 3
• Main Authors: Voz, Marianne, Van de Ven, W. J, Kas, K
• Format: Journal Article Web Resource
• Language: English
• Published: Los Angeles, CA International 01-12-2000; SAGE Publications; International & American Associations for Dental Research
• Subjects: Adenoma, Pleomorphic - genetics; Adenoma, Pleomorphic - pathology; Adenoma, Pleomorphic/genetics/pathology; Cell Transformation, Neoplastic - genetics; Chromosome Aberrations; Chromosomes, Human, Pair 12 - genetics; Chromosomes, Human, Pair 8 - genetics; Dentistry; Diploidy; DNA-Binding Proteins - genetics; Ectoderm - pathology; Endoderm - pathology; Gene Expression Regulation, Neoplastic - genetics; genetic processes; Genetics; Genetics & genetic processes; Génétique & processus génétiques; Humans; Karyotyping; Life sciences; Salivary Gland Neoplasms - genetics; Salivary Gland Neoplasms - pathology; Salivary Gland Neoplasms/genetics/pathology; Sciences du vivant; Translocation, Genetic; Zinc Fingers - genetics; salivary gland; pleomorphic adenoma; zinc finger; PLAG I gene; IGF-II
• ISSN: 0895-9374; 1544-0737; 1544-0737
• DOI: 10.1177/08959374000140011301

Pleomorphic adenoma, or mixed tumor of the salivary glands, is a benign tumor originating from the major and minor salivary glands. Eighty-five percent of these tumors are found in the parotid gland, 10% in the minor (sublingual) salivary glands, and 5% in the submandibular gland. It is the most common type of salivary gland tumor, accounting for almost 50% of all neoplasms in these organs. In fact, after the first observation of recurrent loss of chromosome 22 in meningioma, this was the second type of benign tumor for which non-random chromosomal changes were reported. The rate of malignant change with the potential to metastasize has been reported to be only 2 to 3%, and only a few cases of metastasizing pleomorphic salivary gland adenomas have been described to date. The fact that these tumors arise in organs located in an ontogenetic transitional zone, a region where endoderm and ectoderm meet, might be one of the reasons for the often-problematic histopathological classification. This type of benign tumor has been cytogenetically very well-characterized, with several hundreds of tumors karyotyped. In addition to the cytogenetic subgroup with an apparently normal diploid stemline (making up approximately 30% of the cases), three major cytogenetic subgroups can be distinguished. In addition to a subgroup showing non-recurrent clonal abnormalities, another subgroup is composed of tumors with various translocations involving 12ql5. By far the largest cytogenetic subgroup, however, consists of tumors with chromosome 8 abnormalities, mainly showing translocations involving region 8ql2. The most frequently encountered aberration in this group is a t(3;8)(p21;q12).