Elsevier

Oral Oncology

Volume 44, Issue 6, June 2008, Pages 601-607
Oral Oncology

Odontogenic myxoma: Clinico-pathological, immunohistochemical and ultrastructural findings of a multicentric series

https://doi.org/10.1016/j.oraloncology.2007.08.009Get rights and content

Summary

The aim of this study was to analyze the clinico-pathological and immunohistochemical features of 62 cases of odontogenic myxoma (OM) diagnosed in three Oral Pathology Diagnostic Services in Latin America, as well as to describe the ultrastructural features of three of these cases. OM showed a wide age range (9–71 years), with a mean of 27.97 yr (SD: 11.01) and a male to female ratio of 1:2.2. Mandible was affected in 37 cases (59.6%) and maxilla in 25 (40.4%), with 61.3% located in the posterior region. Thirty-nine cases (62.9%) were multilocular and 23 (37.1%) unilocular. Size ranged from 1 to 13 cm, (mean: 5.2 cm). Thirty-seven multilocular (54.8%) and 6 unilocular lesions (26%) were larger than 4 cm (p < 0.05). Epithelial islands were identified in 5 cases (8%) on H&E stained sections, but AE1/AE3 and CK14 disclosed these structures in 15 cases each (24.2%); CK5 was positive in 8 (12.9%); CK7 in 2 (3.2%) and CK19 in only 3 cases (4.8%). All cases were negative for CKs 8 and 18, S-100 protein, NSE and CD68, and showed a low index of expression of Bcl2 and ki-67 proteins (<1%). Mast cell antibodies showed these cells in 45 cases (72.6%). Myofibroblastic differentiation evidenced by myofilaments and fibronexi was found in one case out of the three studied by TEM and 29 cases (46.7%) were positive by immunohistochemistry for alpha actin. In conclusion, only a minority of OM had epithelial islands, and only 3 cases expressed CK 19, indicating an odontogenic epithelium origin. Immunohistochemical and ultrastructural findings suggest that OM is a mesenchymal neoplasm in which several factors may contribute to its pathogenesis, including myofibroblastic differentiation and the participation of mast cell products. However, further investigations are needed to better understand the participation of these elements in this particular neoplasm.

Introduction

Myxomas of the jaw bones have been traditionally considered to have an odontogenic origin. According to the literature, odontogenic myxomas (OM) represent between 1% and 17.7% of all odontogenic tumors.1, 2, 3 Microscopically these lesions are characterized by stellate and spindle-shaped cells embedded in a richly myxoid extracellular matrix, with little collagen; those cases with higher amounts of collagen may be denominated as myxofibroma.1, 4 These neoplasms are thought to be derived from the mesenchyme of a developing tooth or from the periodontal ligament.5 Islands of inactive odontogenic epithelium may be found in a few cases, but there are no evidences that they exert inductive effects over the surrounding mesenchyme.6 It is unknown the exact nature of OM, but some studies have found that the cells and the extracellular matrix of OM are different from the ectomesenchymal tissues of developing tooth.7, 8, 9

The aim of this study was to analyze the clinico-pathological and immunohistochemical features of 62 cases of OM diagnosed in three Oral Pathology Diagnostic Services in Latin America, as well as to describe the ultrastructural features of three of these cases, in order to explore the possible histogenesis of this neoplasm.

Section snippets

Material and methods

Sixty-two cases of OM of the jaws were retrieved from the files of three Diagnostic Services from North, Central and South America (Oral Pathology Laboratory, Health Care Department, Universidad Autónoma Metropolitana Xochimilco, Mexico [33 cases]; Centro de Medicina Oral de Guatemala, Guatemala City [14 cases], and Oral Pathology Laboratory, School of Dentistry of Piracicaba, State University of Campinas – UNICAMP, Brazil [15 cases]). Clinical and radiographical informations were obtained from

Clinical findings

Fig. 1 shows the age and gender distribution of OM. Age ranged from 9 to 71 years (mean: 27.9 yr, SD: 11.01), and there were 19 male (30.7%) and 43 female (69.3%) patients (male to female ratio 1:2.2). Mandible was affected in 37 cases (59.6%) and maxilla in 25 (40.4%). 22 cases (35.5%) were located in the posterior mandible and 16 (25.8%) in the posterior maxilla, 13 (21%) in the anterior region (11 in the mandible and 2 in the maxilla), 7 (11.3%) affected more than one region (5 cases in the

Discussion

Since its original description by Thoma and Goldman in 194710 the nature of OM has been a matter of controversy. Several studies have been performed in order to define its precise nature, but at present there is not a universally accepted theory about its probable histogenesis. Based on the presence of occasional small islands of odontogenic epithelium, its occurrence almost exclusive in the jawbones and the histomorphological similarity to the mesenchymal component of the developing tooth,

Conflict of interest statement

None declared.

Acknowledgements

This study was funded by CNPq (The National Council for Scientific and Technological Development) and FAPESP, Brazil. Special thanks are due to Ana Cristina do Amaral Godoy for her immunohistochemical assistance.

References (38)

  • C.E. Noffke et al.

    Odontogenic myxoma: review of the literature and report of 30 cases from South Africa

    Oral Surg Oral Med Oral Pathol Oral Radiol Endod

    (2007)
  • R.E. Barros et al.

    Myxoma of the jaws

    Oral Surg Oral Med Oral Pathol

    (1969)
  • J. Peltola et al.

    Odontogenic myxoma – a radiographic study of 21 tumors

    Br J Oral Maxillofac Surg

    (1994)
  • J. Gailit et al.

    The differentiation and function of myofibroblasts is regulated by mast cells mediators

    J Invest Dermatol

    (2001)
  • B.F. Barker

    Odontogenic myxoma

    Semin Diagn Pathol

    (1999)
  • A. Buchner et al.

    Odontogenic myxoma/myxofibroma

  • L. Lo Muzio et al.

    Odontogenic myxoma of the jaws. A clinical, radiologic, immunohistochemical and ultrastructural study

    Oral Surg Oral Med Oral Pathol Oral Radiol Endod

    (1996)
  • S. Moshiri et al.

    Odontogenic myxoma: histochemical and ultrastructural study

    J Oral Pathol Med

    (1992)
  • P.J. Slootweg et al.

    Glycosaminoglycans in myxoma of the jaw: a biochemical study

    J Oral Pathol

    (1985)
  • Cited by (0)

    View full text