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Updated: Mar 16, 2026
Generation and Expansion of Primary, Malignant Pleural Mesothelioma Tumor Lines
Published on: April 21, 2022
Pathology reporting of malignant pleural mesothelioma first diagnosis: A population-based approach
Valeria Ascoli1, Giada Minelli2, Ilaria Cozzi3
1Department of Radiological, Oncological and Anatomo-Pathological Sciences, Sapienza University, Viale Regina Elena, 324, 00161 Rome, Italy.
Abstract:
Accurate pathologic diagnosis and reporting in malignant pleural mesothelioma are essential for clinical care, and cancer registration. Practical guidelines for pathologists are provided in publications and textbooks but it is unclear how these recommendations are applied in routine practice. We investigated the characteristics of pathology reports, and the extent to which they meet guideline standards. We reviewed 819 pathology reports relating to a first diagnosis of malignant pleural mesothelioma. Data sources were a regional section of the Italian network of the Mesothelioma Registry (2001-2014) and a pathology archive (1990-2000). We evaluated tumor characteristics, the diagnosis field including terminology and immunohistochemistry (IHC) workup, and report completeness (the proportion of items recorded). We investigated also two IHC panels identified by the most used markers in current practical guidelines, one best suited for epithelioid mesotheliomas (combinations of at least 2 positive and at least 2 negative mesothelioma markers) and the other best suited for sarcomatoid mesotheliomas (positive mesothelioma markers plus cytokeratins). Reports (753 histology, 66 cytology, IHC-confirmed 86%) were 74% complete and always narrative. Missing data were related to clinical history (76%), tumor laterality (61%), specimen size (38%), and histological subtype (23%). The proportion of cases with IHC was higher for epithelioid (90%) than sarcomatoid mesothelioma (87%). Compliance to IHC recommendations was higher for epithelioid (59%) than sarcomatoid mesothelioma (11%). The mean number of stains was significantly higher for sarcomatoid than epithelioid mesothelioma (p<0.000; Kruskal-Wallis test). Our findings show that although guidelines are designed to improve actual reporting practices, there is ample room for improvement in their application to standardize the diagnosis of mesothelioma. Synoptic pathology reporting needs to be implemented to better utilize pathology information.
Insights
Pathology reports for malignant pleural mesothelioma are often incomplete and do not fully adhere to diagnostic guidelines. Implementing synoptic reporting can improve the standardization of mesothelioma diagnosis.
Area of Science:
- Pathology
- Oncology
- Cancer Diagnostics
Background:
- Accurate diagnosis and reporting of malignant pleural mesothelioma are crucial for patient care and cancer registration.
- Existing pathology guidelines provide recommendations, but their routine application in practice remains unclear.
Purpose of the Study:
- To investigate the characteristics of malignant pleural mesothelioma pathology reports.
- To assess the extent to which these reports meet current diagnostic guideline standards.
- To evaluate the application of immunohistochemistry (IHC) in mesothelioma diagnosis.
Main Methods:
- Review of 819 pathology reports for first-time malignant pleural mesothelioma diagnoses from Italian Mesothelioma Registry and pathology archives.
- Evaluation of tumor characteristics, diagnostic terminology, IHC workup, and report completeness.
- Assessment of compliance with IHC panels for epithelioid and sarcomatoid mesothelioma.
Main Results:
- Pathology reports were 74% complete, with frequent missing data on clinical history, tumor laterality, specimen size, and histological subtype.
- While IHC use was high for both epithelioid (90%) and sarcomatoid (87%) mesothelioma, compliance with recommended IHC panels was significantly lower for sarcomatoid (11%) compared to epithelioid (59%) types.
- The mean number of IHC stains used was higher for sarcomatoid than epithelioid mesothelioma.
Conclusions:
- Current pathology reporting practices for malignant pleural mesothelioma show significant room for improvement in adhering to established guidelines.
- Standardization of mesothelioma diagnosis requires better implementation of guidelines and potentially the adoption of synoptic pathology reporting.
