NK cell density in malignant skin tumours--a stereological study

Area of Science:

• Immunology
• Oncology
• Dermatopathology

Background:

• Natural killer (NK) cells are crucial immune components involved in tumor surveillance.
• Understanding NK cell infiltration in skin cancers is vital for evaluating their role in anti-tumor immunity.

Purpose of the Study:

• To quantify and compare the density of NK cells in malignant melanoma and squamous cell carcinoma tissues.
• To assess the NK cell to tumor cell ratio in these skin malignancies.

Main Methods:

• Immunohistological staining was employed to identify NK cells.
• Stereological methods were used for quantitative density measurements in frozen tissue sections.
• Comparison was made between neoplastic skin tissues and non-neoplastic tonsil tissues.

Main Results:

• NK cell density was significantly lower in malignant melanoma (5.0 ± 1.5 x 10^3/mm^3) and squamous cell carcinoma (5.1 ± 2.7 x 10^3/mm^3) compared to tonsil germinal centers (5.0 ± 0.8 x 10^4/mm^3).
• The NK cell to tumor cell ratio was markedly reduced in melanoma and squamous cell carcinoma, being 10^2-10^4 times lower than typical in vitro assay values.

Conclusions:

• The infiltration of NK cells into malignant melanoma and squamous cell carcinoma is significantly diminished.
• The functional relevance of NK cells in the context of these malignant skin tumors warrants careful consideration and further investigation.