Macrophage and dendritic cell infiltration in head and neck squamous-cell carcinoma; an immunohistochemical study

Area of Science:

• Immunology
• Oncology
• Pathology

Background:

• Head and neck squamous-cell carcinoma involves complex immune cell interactions.
• Understanding the infiltration patterns of lymphoid cells, particularly monocyte-derived macrophages and dendritic cells, is crucial for comprehending anti-tumor immunity.

Purpose of the Study:

• To elucidate the tumor-infiltrating patterns of CD68+ scavenger macrophages and MHC-class-II+/S100+ antigen-presenting dendritic cells in head and neck squamous-cell carcinoma.
• To investigate the functional roles of these cells in tumor immunity and their relationship with transmembranal factors.

Main Methods:

• Histochemical analysis of tumor tissues to identify and localize immune cells.
• Characterization of CD68+, acid-phosphatase-expressing macrophages and MHC-class-II+, S100-antigen-presenting dendritic cells.
• Assessment of intra-epithelial and stromal infiltration patterns.

Main Results:

• Distinctive small fields of lymphocytes with intermingled dendritic cells were observed in the tumor stroma.
• Low intra-epithelial dendritic cell infiltration was noted.
• Macrophages showed substantial stromal invasion and inconsistent intra-epithelial invasion, with novel granuloma-like structures reported.
• Dendritic cells appear involved in tumor antigen sensitization, while macrophages contribute to cytotoxicity and debris scavenging.

Conclusions:

• The study provides insights into the distinct roles of dendritic cells and macrophages in head and neck squamous-cell carcinoma immunity.
• Novel macrophage-like structures were identified in the tumor stroma.
• No direct relationship was found between transmembranal factor intensity and the infiltration patterns of these immune cells.