Immunohistochemical Localization of Epithelial Mesenchymal Transition Markers in Cyclosporine A Induced Gingival Overgrowth.

INTRODUCTION: Cyclosporine, an immunosuppressive agent used in the management of renal transplant patients is known to produce Drug Induced Gingival Overgrowth (DIGO) as a side effect. Several mechanisms have been elucidated to understand the pathogenesis of DIGO. Recently, epithelial mesenchymal transition has been proposed as a mechanism underlying fibrosis of various organs. AIM: The aim of the study was to investigate if Epithelial Mesenchymal Transition (EMT) operates in Cyclosporine induced gingival overgrowth. MATERIALS AND METHODS: The study involved obtaining gingival tissue samples from healthy individuals (n=17) and subjects who exhibited cyclosporine induced gingival overgrowth (n=18). Presence and distribution of E-Cadherin, S100 A4 and alpha smooth muscle actin (α-SMA) was assessed using immunohistochemistry and cell types involved in their expression were determined. The number of α- SMA positive fibroblasts were counted in the samples. RESULTS: In control group, there was no loss of E-Cadherin and a pronounced staining was seen in the all layers of the epithelium in all the samples analysed (100%). S100 A4 staining was noted in langerhans cells, fibroblasts, endothelial cells and endothelial lined blood capillaries in Connective Tissue (CT) of all the samples (100%) while α - SMA staining was seen only on the endothelial lined blood capillaries in all the samples (100%). However in DIGO, there was positive staining of E-Cadherin only in the basal and suprabasal layers of the epithelium in all the samples (100%). Moreover there was focal loss of E-Cadherin in the epithelium in eight out of 18 samples (44%). A break in the continuity of the basement membrane was noted in three out of 18 samples (16%) on H & E staining. CONCLUSION: Based on the analysis of differential staining of the markers, it can be concluded that EMT could be one of the mechanistic pathways underlying the pathogenesis of DIGO.

Spindle cell carcinoma of the gingiva: A rare occurrence.

Of the many neoplasms known, squamous cell carcinoma (SCC) is the most common to affect the oral cavity. Spindle cell carcinoma (SpCC) is considered a rare high malignant variant of SCC occurring predominantly in the upper aerodigestive tract. Soft-tissue spindle cell neoplasms are quite uncommon in the oral cavity reportedly accounting for lesser than 1% of all tumors in the oral region. Our case shows an unusual presentation of SpCC involving the mandibular gingiva in a 46-year-old smoker patient, which presented as a firm, erythematous swelling with surface necrosis. An incisional biopsy was performed for microscopic evaluation to confirm the clinical diagnosis and for treatment planning.