Qualitative Assessment of Collagen and Elastic Fibers in Oral Submucous Fibrosis (OSMF), OSMF with Dysplasia and Oral Squamous Cell Carcinoma Arising from OSMF: A Histochemical Study

BACKGROUND

Oral submucous fibrosis (OSMF) is a habit related potentially malignant disorder seen mainly in South Asian people. The malignancy arising from OSMF has been regarded as low grade with better outcome. The present study was orchestrated to histochemically analyze collagen and elastic fibres in OSMF without dysplasia, OSMF with dysplasia and OSMF turning malignant.

MATERIALS AND METHODS

100 cases (80 cases and 20 healthy controls) were included after obtaining clearance from ethical committee. All cases were subjected to Van Gieson staining for collagen and a novel simple method for elastic fibres (Orcein staining). Data were analyzed using SPSS software.

RESULTS

Controls showed haphazard arrangement of collagen and elastic fibres. The collagen bundles were parallelly arranged in OSMF without dysplasia and OSMF with dysplasia; the collagen was however haphazard in cases of OSMF turning malignant. As with collagen, elastic fibres were also haphazardly arranged in the control group; in contrast, the elastic fibres were predominantly arranged in a criss-cross pattern in the other study groups. The difference in orientation and density among the groups was statistically significant.

CONCLUSION

With advancement of stage there is increased collagenization of OSMF, as the condition acquires dysplastic changes and turns malignant, microenvironment alters resulting in increased activity of collagenases. However, the arrangement of more resistant elastic fibres depicts the better outcome, once OSMF shows malignant transformation, limiting locoregional and distant spread.

Comparison of Diagnostic Reliability of p63 and Smooth Muscle Actin in Salivary Gland Neoplasms

Salivary gland neoplasms pose considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants & similar histological features with other tumor entities. Myoepithelial and basal cells play a significant role in the pathogenesis of salivary gland neoplasm. p63 and smooth muscle actin are more reliable markers for identifying these cells and not studied much comparing their reliability in the diagnosis of salivary gland neoplasms. Hence, the aim of this study is to evaluate and compare the diagnostic reliability of immunohistochemical markers such as p63 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms. The study comprises of 18 samples categorized into two groups: Group I comprised 9 cases, of which 4 cases were Pleomorphic adenoma, 2 cases were Myoepithelioma, 2 cases of Basal cell adenoma and 1 case was Warthin's tumor; and Group II consisted of 9cases, of which 3 was Mucoepidermoid carcinoma, 1 cases were Myoepithelial carcinoma and 5 cases were Adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of p63 and smooth muscle actin. The obtained data was analysed statistically by using Mann-Whitney test. In SMA, strong positivity for epithelial and connective tissue components of benign salivary neoplasm is about 22.2%respectively. In malignant salivary neoplasm, SMA was strongly positive for the epithelial and connective tissue component of about 77.7% and 88.8% cases respectively. The difference in the connective tissue components was found to be statistically significant (U = 24, P = 0.032). P63 was strongly positive for the epithelial and connective tissue component of benign salivary neoplasm of about 33.3% and 11.1% cases respectively.In malignant salivary neoplasm, p63 was strongly positive for the epithelial component of about 66.6% cases and connective tissue is completely negative. Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors and even p63 can be used as specific markers for differentiation of malignant salivary gland tumors.