Immunohistochemical Expression of BCL-2 in Malignant Salivary Gland Tumors

Abstract

Background: Malignant salivary gland tumors (MSGTs) consist of a heterogeneous group of neoplasms with complex clinicopathological features and biological behaviors. The purpose of this study was to determine the expression of Bcl-2 antiapoptotic protein in mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ADCC), acinic cell carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA) of salivary glands and to find out its association with different grades of these tumors.
 Material and Methods: This descriptive study included 55 cases of MSGTs. Tissue sections were stained with routine hematoxylin and eosin stain as well as Bcl-2 immunostain. MSGTs were graded as low grade (Low grade MEC, ACC, PLGA, and tubular pattern of ADCC), intermediate grade (cribriform pattern of ADCC, and intermediate grade of MEC) and high grade (high grade of MEC and solid pattern of ADCC) tumors on H&E sections. Bcl-2 expression was scored as ‘negative’ (<5% of neoplastic cells), ‘1’ (5-19% of neoplastic cells), ‘2’ (20-49% of neoplastic cells), and ‘3’ (>50% of neoplastic cells), respectively.
 Results: MSGTs most commonly involved the parotid gland (52.7%), while ADCC (40%) and MEC (38.2%) were the most common tumors. Expression of Bcl-2 was strongly positive in 56.4% cases of MSGTs which included ADCC (71%), MEC (19.4%) and ACC (9.7%), respectively. A significant association was found between Bcl-2 staining and types of MSGTs i.e., MEC, ADCC, ACC (P = .001) as well as between Bcl-2 staining and grades of MSGTs (P = .013).
 Conclusions: Bcl-2 protein is expressed in malignant salivary gland tumors. Its expression maybe helpful in grading small biopsies, predicting behavior, and planning targeted therapy of MSGTs.
 

Immunohistochemical Expression of Ki-67 in Malignant Salivary Glands Tumors

“…0261 Dated 13/01/2020. Sample size was calculated by the previous study conducted by Abed et al 7 3 LG of MSGTs comprised of LG of ADCC (Tubular Pattern), MEC, ACC, and PLGA. IG of MSGTs consisted of Swiss cheese/cribriform pattern of ADCC, and IG of MEC.…”

“…HG of MSGTs comprised of HG of MEC and HG of ADCC (Solid Pattern). 3 Ki-67 cut off value for negative expression was taken as less than 5 malignant cells per 10 HPF (High Power Field). While positive expression was taken as weak positive (WP-1) when 5-19% of malignant cells expressed positivity, moderate positive (MP-2) when 20-49% of malignant cells expressed positivity and strong positive (SP-3) when >50% of malignant cells expressed positivity.…”

“…diverse morphology which produces difficulty in diagnosis yet its accuracy play an important role in superior treatment. 3 Definitive diagnosis of salivary glands malignancies is based on cell morphology and cellular differentiation. Stromal changes, neural invasion, architecture and growth pattern of the tumor borders are also key features of histological diagnosis, however, still these tumors give diagnostic challenge in certain cases.…”

“…Stromal changes, neural invasion, architecture and growth pattern of the tumor borders are also key features of histological diagnosis, however, still these tumors give diagnostic challenge in certain cases. 3 Immunohistochemistry can be used in certain cases where cell type, differentiation, and proliferation are required to assess. Cell proliferation is a basic biological process in tumorogenisis.…”