Pathology of diffuse malignant pleural mesothelioma

Area of Science:

• Pathology
• Oncology

Background:

• Accurate diagnosis of diffuse malignant pleural mesothelioma is crucial for effective treatment.
• Pathological examination with special techniques is generally required for diagnosis.
• Immunohistochemistry has improved mesothelioma diagnosis but challenges persist due to mimicry by reactive hyperplasias and tumors.

Purpose of the Study:

• To review diagnostic techniques for diffuse malignant pleural mesothelioma.
• To highlight the role of immunohistochemistry in differentiating mesothelioma from mimics.
• To discuss ongoing challenges and future directions in mesothelioma diagnosis.

Main Methods:

• Review of pathological examination techniques, including conventional histology, histochemistry, electron microscopy, and immunohistochemistry.
• Discussion of morphological examination for distinguishing mesothelioma from reactive mesothelial proliferations.
• Mention of recent cytogenetic studies in mesothelioma.

Main Results:

• Mesotheliomas are classified into epithelial, mixed, sarcomatoid, and undifferentiated types, providing prognostic information.
• Immunohistochemistry is effective in distinguishing epithelial mesothelioma from metastatic adenocarcinoma and sarcomatoid mesothelioma from its mimics.
• Distinguishing mesothelioma from reactive mesothelial proliferations remains challenging based on morphology alone.

Conclusions:

• While immunohistochemistry is a valuable tool, diagnostic difficulties in mesothelioma persist.
• Morphological examination remains critical, especially for differentiating mesothelioma from reactive proliferations.
• Cytogenetic studies show promise for future diagnostic assistance in mesothelioma.