Relationship between major and minor salivary gland mucoepidermoid carcinoma malignancy grading and presence of stromal myofibroblasts: immunohistochemical study.
OBJECTIVE
Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumour, classified as low, intermediate and high grade. Myofibroblasts are the main stromal component and are included as prognostic factor in some tumours. The aim of this study was to evaluate the myofibroblasts in the stroma of MEC with possible relationship to malignancy grading.


METHODS
Twenty-five cases of MEC (six low grade, 11 intermediate grade, four high grade and four metastasis) were stained for vimentin, desmin and smooth muscle actin (SMA) for the identification of myofibroblasts. Transforming growth factors (TGFbeta1 and TGFbetaRII) were also assessed in our study.


RESULTS
Myofibroblasts were present in all cases, in amounts varying according to histological grading. TGFbeta1 was positive in squamous cells of intermediate grade tumours, and in the stroma of only four cases. TGFbetaRII was positive in most squamous and intermediate cells, regardless of malignancy grading.


CONCLUSIONS
Our study showed that the analysis of neoplastic stroma must be added to the studies of neoplastic cells to draw a better picture leading to tumour diagnosis and prognosis.
Sobral
Ana Paula Veras
AP
Oral Pathology Department, School of Dentistry, University of Pernambuco, PE, Brazil. anapaula@fop.upe.br
Loducca
Silvia Vanessa L
SV
Nunes
Fábio Daumas
FD
de Araújo
Ney Soares
NS
Kowalski
Luiz Paulo
LP
de Araújo
Vera Cavalcanti
VC
D000199:Actins / Q000032:analysis / Q000096:biosynthesis; D018277:Carcinoma, Mucoepidermoid / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D003893:Desmin / Q000032:analysis / Q000096:biosynthesis; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis / Q000096:biosynthesis; D012468:Salivary Gland Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D017154:Stromal Cells / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000096:biosynthesis; D053773:Transforming Growth Factor beta1; D014746:Vimentin / Q000032:analysis / Q000096:biosynthesis
D000199:Actins; D003893:Desmin; D009363:Neoplasm Proteins; D018125:Receptors, Transforming Growth Factor beta; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014746:Vimentin; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II