Masson trichrome stain helps differentiate myofibroma from smooth muscle lesions in the head and neck region.
ABSTRACT 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.
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.
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.
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.
SourceAvailable from: PubMed Central[Show abstract] [Hide abstract]
ABSTRACT: Myofibromas are benign uncommon fibroblastic tumors of the soft tissue, bone, or internal organs affecting all ages. These lesions histopathologically may mimic many other soft tissue tumors of the oral cavity such as spindle cell tumors of neurogenic and smooth muscle cell origin, thus leading to misdiagnosis and mistreatment. This case report describes a rare benign tumor, which presented as a soft tissue swelling on posterior gingiva. Surgical excision of the lesion was carried out under local anaesthesia. Histopathologic and immunohistochemical examination confirmed the diagnosis of myofibroma. Myofibroma should be included in the clinical differential diagnosis of masses of the oral soft tissues; however immunohistochemical examination is essential to establish an accurate diagnosis.01/2015; 2015:243894. DOI:10.1155/2015/243894
The Korean Journal of Pathology 08/2014; 48(4):307-10. DOI:10.4132/KoreanJPathol.2014.48.4.307 · 0.17 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Angioleiomyoma (AL) is a benign neoplasia originating from smooth muscle and very uncommon in the oral cavity. The most fre-quent subtype in the oral cavity is the vascular one. AL usually occurs in the extremities: only around 12% are found in other areas such as head and neck. It presents as an asymptomatic, slow growing nodule lodging in the palate, tongue or lips. The diagnosis is essentially by histological exam and special specific stains are helpful to confirm the origin and to distinguish it from other tumors. We present a case of AL found in unusual site: attached to the sub-mandibular region in a deep-seated space.