S-100 protein in malignant mesotheliomas

Area of Science:

• Oncology
• Cell Biology
• Histopathology

Background:

• S-100 protein is a calcium-binding protein traditionally associated with neuro-ectodermal tissues.
• Recent studies indicate S-100 protein expression in non-neuro-ectodermal sites.
• Mesothelial proliferations encompass benign reactive changes and malignant neoplasms.

Purpose of the Study:

• To investigate the expression of S-100 protein in various mesothelial lesions, including malignant mesotheliomas and reactive mesothelial proliferations.
• To determine if S-100 protein expression correlates with specific histological subtypes of mesothelioma or reactive mesothelial processes.

Main Methods:

• Immunohistochemical analysis was performed to detect S-100 protein.
• S-100 protein expression was evaluated in samples of epithelial malignant mesothelioma, biphasic malignant mesothelioma, sarcomatous malignant mesothelioma, reactive mesothelial lesions, and normal mesothelium.

Main Results:

• S-100 protein was present in epithelial and biphasic malignant mesotheliomas.
• One out of seven reactive mesothelial lesions showed S-100 protein positivity.
• Sarcomatous malignant mesotheliomas, the majority of reactive mesothelial lesions, and normal mesothelium lacked S-100 protein expression.

Conclusions:

• The detection of S-100 protein in certain mesothelial cells, particularly in malignant and some reactive proliferations, is reported.
• S-100 protein expression in mesothelial cells may serve as a potential indicator of intense cellular proliferation.
• This finding expands the known expression profile of S-100 protein beyond its classical neuro-ectodermal origins.