Immunohistochemical Expression of Myofibroblasts Using Alpha-smooth Muscle Actin (SMA) to Assess the Aggressive Potential of Various Clinical Subtypes of Ameloblastoma

J Microsc Ultrastruct. 2019 Jul-Sep;7(3):130-135. doi: 10.4103/JMAU.JMAU_10_19.

Abstract

Objective: Ameloblastoma is a rare odontogenic neoplasm with high recurrence rates if improperly treated. If left untreated (or is treated inadequately), it can cause substantial morbidity, disfigurement, and even death. Hence, there is a need to explore the stromal cells too, which might play an important role in assessing its aggressive behavior and may help to predict the recurrence of different clinical variants of ameloblastoma. Myofibroblasts (MFs) are such cells which have been studied in various lesions.

Materials and methods: This retrospective study involved archival tissues of ameloblastoma. Among a total of 40 cases, 12 cases of SMA (solid multicystic ameloblastoma), 10 cases of unicystic ameloblastoma (UA), 8 cases of desmoplastic ameloblastoma, and 10 cases of oral squamous cell carcinoma were selected as control. Immunohistochemical staining with anti-alpha-smooth muscle actin antibody was done. Interpretation of ten examined fields was counted by three observers.

Results: Significant difference in the number of MFs in SMA and UA and desmoplastic ameloblastoma and UA (P < 0.05) was found. However, there was no statistically significant difference in MFs of SMA and desmoplastic ameloblastomas (P > 0.05). In addition, there was no statistically significant difference in the staining intensity between the three variants (P > 0.05).

Conclusion: A significant correlation was obtained between the number of MF in all the three clinical variants, i.e., SMA, UA, and desmoplastic ameloblastoma (P = 0.02), which is the unique feature of the study.

Keywords: Alpha-smooth muscle actin; ameloblastoma; clinical variants; types.