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

Adv Dent Res. 2000 Dec:14:81-3. 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 various translocations involving 12q15. By far the largest cytogenetic subgroup, however, consists of tumors with chromosome 8 abnormalities, mainly showing translocations involving region 8q12. The most frequently encountered aberration in this group is a t(3;8)(p21;q12).

Publication types

  • Review

MeSH terms

  • Adenoma, Pleomorphic / genetics*
  • Adenoma, Pleomorphic / pathology
  • Cell Transformation, Neoplastic / genetics
  • Chromosome Aberrations
  • Chromosomes, Human, Pair 12 / genetics
  • Chromosomes, Human, Pair 8 / genetics
  • DNA-Binding Proteins / genetics
  • Diploidy
  • Ectoderm / pathology
  • Endoderm / pathology
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • Karyotyping
  • Salivary Gland Neoplasms / genetics*
  • Salivary Gland Neoplasms / pathology
  • Translocation, Genetic
  • Zinc Fingers / genetics


  • DNA-Binding Proteins
  • PLAG1 protein, human