Myofibroblasts in odontogenic cysts and tumors: An immunohistochemical study

Abstract

Objective: The objective of this study was to assess immunohistochemically the presence of myofibroblasts both qualitatively and quantitatively in odontogenic cysts and tumors and to compare with the control cases of squamous cell carcinoma and to correlate the results with biologic behavior of these lesions. Materials and Methodology: Formalin-fixed, paraffin-embedded blocks of odontogenic cysts and tumors were retrieved from institutional archives. The sample size is 40; these include ten cases of odontogenic keratocyst (OKC) ( n = 10), five cases of dentigerous cyst ( n = 5), ten cases of solid ameloblastoma ( n = 10), and five cases of unicystic ameloblastoma ( n = 5). Ten cases of squamous cell carcinoma ( n = 10) served as control. Sections were taken and stained immunohistochemically using alpha-smooth muscle actin for evaluation of myofibroblasts. The number of positive stromal cells was evaluated both for quantitative and qualitative analyses. Results: The present study showed that the mean number of myofibroblasts among the odontogenic cysts and tumors was higher in locally aggressive lesions such as OKC (23.79 ± 19.95), solid ameloblastoma (26.38 ± 17.00), and unicystic ameloblastoma (20.74 ± 14.86) which were comparable to squamous cell carcinoma (21.49 ± 9.76) when compared to benign lesions like dentigerous cyst which showed the least number of myofibroblasts (13.1 ± 7.71). Qualitatively, the staining intensity of myofibroblasts showed a significant variation within the same lesion and among different lesions. There was a distinct difference in the morphology, pattern of arrangement, and distribution of myofibroblasts among the studied lesions. Conclusion: We conclude that the increase in the number of myofibroblasts could be one of the contributory factors for the locally aggressive behavior of benign lesions such as ameloblastomas and OKCs. Further studies are suggested to understand the mechanism by which these important cellular elements exert their effects on stromal and epithelial tissue compartments.

Stromal Myofibroblasts in Correlation With Inflammation and Impacted Tooth in Odontogenic Cysts: An Immunohistochemical Comparative Study

“…MFs are differentiated broblasts that express α-SMA and have intermediate characteristics between conventional broblasts and smooth muscle cells [30] being able to remodel and degrade the extracellular matrix by secreting matrix metalloproteinases, driving the invasive growth of lesions odontogenic cyst [31]. The few studies that investigated the presence of MFs in odontogenic lesions suggest that the increase in the number of these cells contributes to the progression of the lesion and more aggressive biological behavior [13,17,21,24,25,32,33]. Anusai et al [10] reported that epithelial and stromal cell interactions are fundamental in controlling the growth and clinical behavior of odontogenic cystic lesions and that MFs are seen in greater numbers in OKC than in DC.…”

Miofibroblastos estromais em correlação com inflamação e dente impactado em cistos odontogênicos: um estudo imunohistoquímico comparativo

“…MFs são fibroblastos diferenciados que expressam α-SMA e possuem características intermediárias entre fibroblastos convencionais e células musculares lisas (Hinz, 2020) sendo capazes de remodelar e degradar a matriz extracelular por meio da secreção de metaloproteínases da matriz, conduzindo o crescimento invasivo de lesões císticas odontogênicas (Roy e Gard, 2013). Os poucos estudos que investigaram a presença de MFs em lesões odontogênicas sugerem que o aumento no número dessas células contribui para a progressão da lesão e comportamento biológico mais agressivo (Vered et al, 2005;Nadalin et al, 2012;Syamala et al, 2016;Dandena et al, 2017;Santos et al, 2017;Pereira et al, 2018;Pinisetti;Tadi;Manyam, 2022). A vimentina é um filamento intermediário de classe II expresso principalmente no tecido mesenquimal (Sudhakara et al, 2016).…”