Masson trichrome stain helps differentiate myofibroma from smooth muscle lesions in the head and neck region.

Abstract

BACKGROUND/PURPOSE:

Myofibromas are well described in the head and neck region, but differentiating them from smooth muscle lesions is still difficult using smooth muscle immunohistochemical stains. This study evaluated the usefulness of the Masson trichrome stain in differentiating myofibromas from smooth muscle lesions in the head and neck region.

METHODS:

Samples of 11 oral myofibromas, two leiomyomas, one angioleiomyoma, and one smooth muscle hamartoma were retrieved from our archives. Immunohistochemistry and Masson trichrome stains were performed on tissue sections of these lesions.

RESULTS:

All 11 oral myofibromas, seven from male patients and four from female patients, were solitary myofibromas. The patients' mean age at diagnosis was 32.8 years. Oral myofibromas occurred most commonly on the gingiva (four cases) and in the mandible (three cases). With the Masson trichrome stain, the smooth muscle cell cytoplasm was stained red, while the collagenous fibrous tissue was stained blue. Myofibromas and smooth muscle lesions demonstrated different characteristic patterns with the Masson trichrome stain. Myofibromas were composed of a much more collagenous stroma intermixed with the spindle cells. Thick fibrous bundles with random, irregularly intersecting angles were prominent in myofibromas. Smooth muscle lesions showed only minimal delicate fibrous tissue surrounding the smooth muscle cells and in the septa between the smooth muscle masses. On low-power view, red masses of smooth muscle tumor surrounded by blue fibrous tissue were observed.

CONCLUSION:

The Masson trichrome stain can be a useful tool to differentiate myofibromas from smooth muscle lesions, but immunohistochemical methods to rule out other spindle cell lesions are still needed.

• Authors: Julia Yu Fong Chang, Harvey P Kessler
• Journal: Journal of the Formosan Medical Association = Taiwan yi zhi (J Formos Med Assoc) Vol. 107 Issue 10 Pg. 767-73 (Oct 2008) ISSN: 0929-6646 [Print] Singapore
• PMID: 18926943 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Azo Compounds
• Coloring Agents
• trichrome stain
• Methyl Green
• Eosine Yellowish-(YS)

Topics

• Adolescent
• Adult
• Aged
• Azo Compounds
• Child
• Coloring Agents
• Diagnosis, Differential
• Eosine Yellowish-(YS)
• Female
• Hamartoma (diagnosis)
• Humans
• Leiomyoma (diagnosis)
• Male
• Methyl Green
• Middle Aged
• Mouth Neoplasms (diagnosis)
• Myofibroma (diagnosis)
• Staining and Labeling