الفهرس | Only 14 pages are availabe for public view |
Abstract The salivary glands are classified as major and minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor glands include small mucus-secreting glands located throughout the palate, nasal and oral cavity. Salivary gland cancer is rare, with 6% of head and neck tumors forming in the salivary glands, the majority in the parotid. Due to the diverse nature of salivary gland tumors, many different terms and classification systems have been used. Perhaps the most widely used currently is that system proposed by the World Health Organization in 2005, which classifies salivary neoplasms as primary or secondary, benign or malignant, and also by tissue of origin. This system defines five broad categories of salivary gland neoplasms. Immunohistochemistry is an important tool that can help to determine the biological differences in the behaviors of different tumors. Identification of proliferating activities in tumors may be useful to predict their biological behavior. Ki-67 is one of the most widely used and trustworthy proliferation markers. Ki-67 has been used to determine the proliferation rate of many tumors, including salivary gland tumors. Midkine (MK) is a heparin-binding growth factor. Although it is highly expressed in the midgestation period, MK is not detected in healthy adults. Many studies showed high expression of MK in various types of tumors. MK plays a significant role in carcinogenesis related activities, such as fibrinolysis, cell migration, anti-apoptosis, transformation and angiogenesis. In this study, an attempt was made to correlate between MK and Ki-67 protein expression in SGTs by using archival paraffin sections of 25 cases. All cases were submitted for immunohistochemistry by Midkine and Ki-67 monoclonal antibodies. Immunostaining was evaluated using area fraction. The study concluded that there is a significant difference in MK and Ki-67 protein expression with higher expression in malignant SGTs compared to benign tumors. Moreover, there is a significant strong positive correlation between MK and Ki-67 protein expression in different types of SGTs. |