CD163 expression in M2 macrophages of primary and metastatic head and neck squamous cell carcinoma

Due of its influence on tumour behaviour, the tumour microenvironment and its components have garnered interest recently. This microenvironment is dominated by M2 macrophages. This study examined the percentage of M2 macrophage expression in head and neck squamous cell carcinoma at the primary tumour location, regardless of grade. This connection was further examined utilising CD163 immunohistochemical labelling at the primary tumour and associated lymph node metastases. A total of 20 squamous cell carcinoma samples were categorised into four groups: grade I, II, and III at the main tumour site and grade III metastases to the lymph nodes. After immunohistochemically labelling samples for CD163, the percentage of CD163 expression in each sample was measured by manually counting positive and negative cells in five unmounted microscopic fields at 40 × 10 magnification and computing the mean. There were no documented data confirming the presence of Human papilloma virus relation to the SCC cases. Therefore, the HPV status was not included in our research. A statistically significant correlation was found between the increased percentage of CD163-positive M2 macrophage expression in head and neck squamous cell carcinoma by immunohistochemistry stain and the increased histological grade at the site of the primary tumor. M2 macrophage expression was also found in metastases of head and neck squamous cell carcinoma to lymph nodes. However, this expression was not statistically significantly correlated with its expression at the site of the primary tumor. This study found an association between CD163-positive M2 macrophages and higher histological grade at the primary tumour site, suggesting that head and neck squamous cell carcinoma samples with higher CD163 expression could have a worse prognosis and further researche are required to confirm this correlation.