Indian Journal of Pathology and Microbiology

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 61  |  Issue : 4  |  Page : 479--484

Expression of α-smooth muscle actin in benign and malignant salivary gland tumors: An immunohistochemical study


Mahalakshmi Ravi, Karen Boaz, Srikant Natarajan, Amitha Lewis, Mukul Prasad, Swetha Yellapurkar 
 Department of Oral Pathology and Microbiology, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Mangalore, Karnataka, India

Correspondence Address:
Karen Boaz
Department of Oral Pathology and Microbiology, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Mangalore, Karnataka
India

Background and Objectives: Myoepithelial cells (ME) are known to contribute in the patterning of salivary gland neoplasms (SGN) and possess cytoplasmic smooth muscle actin (SMA) revealed by alpha SMA (α-SMA). The present study aimed to assess the expression of α-SMA in selected benign and malignant SGN (pleomorphic adenoma [PA], mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and polymorphous low-grade adenocarcinoma (PLGA). Materials and Methods: The intensity and pattern of expression of α-SMA were studied in 25 cases of SGN's ACC (n = 7), MEC (n = 8), PA (n = 8), and PLGA (n = 2), and correlated with the histological patterns. Results: Maximum expression of α-SMA in the epithelial compartment was seen in ACC, followed by PA, whereas MEC and PLGA showed completely negative staining. The connective tissue expression was mild in ACC and MEC. The myxoid stroma of PA with “melting” pattern was weakly positive for α-SMA. The stroma in PLGA showed complete negativity. In ACC, α-SMA-positive cells were lining the cribriform spaces, small islands, and dispersed within large islands. Small nests showed complete positivity for α-SMA. Interpretation and Conclusion: In ACC, α-SMA expression supports the involvement of ME in epithelial organization explaining the histological patterns seen. In PA, the expression correlates with the predominantly secretory nature of ME. The absence of epithelial positivity in MEC and PLGA suggest that ME has less role to play in their histogenesis. The weak stromal positivity observed in MEC and ACC may be attributed to the positive immunoreactivity of myofibroblasts playing a role in modulating the course of SGN's.


How to cite this article:
Ravi M, Boaz K, Natarajan S, Lewis A, Prasad M, Yellapurkar S. Expression of α-smooth muscle actin in benign and malignant salivary gland tumors: An immunohistochemical study.Indian J Pathol Microbiol 2018;61:479-484


How to cite this URL:
Ravi M, Boaz K, Natarajan S, Lewis A, Prasad M, Yellapurkar S. Expression of α-smooth muscle actin in benign and malignant salivary gland tumors: An immunohistochemical study. Indian J Pathol Microbiol [serial online] 2018 [cited 2019 Jun 16 ];61:479-484
Available from: http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2018;volume=61;issue=4;spage=479;epage=484;aulast=Ravi;type=0