Pathology reporting of malignant pleural mesothelioma first diagnosis: A population-based approach

Our plain-English summary of Pathology reporting of malignant pleural mesothelioma first diagnosis: A population-based approach, by V. Ascoli, G. Minelli, I. Cozzi, et al (Pathology, Research and Practice, 2016).

The study

• Authors: V. Ascoli, G. Minelli, I. Cozzi, E. Romeo, C. Carnovale Scalzo, L. Ancona, F. Forastiere
• Journal: Pathology, Research and Practice
• Published: 2016;212(10):886-892
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

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.

Copyright © 2016 Elsevier GmbH. All rights reserved.

In plain English

This study reviewed 819 pathology reports giving a first diagnosis of malignant pleural mesothelioma in the Lazio Region of Italy, which includes Rome. The reports came from the regional section of the Italian Mesothelioma Registry (2001–2014) and an earlier pathology archive (1990–2000). The authors checked how complete each report was. They also compared the use of immunohistochemistry (IHC), stains that help confirm the diagnosis, with guidelines. On average, reports were 74.2% complete. Clinical history was missing in 76.3% of reports, the side of the tumor in 61.3%, and the tumor subtype in about 23%. IHC was done in 86.1% of reports. Of 445 epithelioid mesotheliomas with IHC, 264 (59.3%) used the guideline combination of at least 2 positive and 2 negative markers. Of 66 sarcomatoid mesotheliomas with IHC, 7 (10.6%) used the recommended multiple cytokeratins plus at least 2 positive markers. Reports without IHC fell from 20% before 2007 to 8.5% after. The authors concluded that reports vary widely in how closely they follow guidelines, and that structured (synoptic) reporting is needed. They did not re-check whether the diagnoses themselves were correct.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Population-based retrospective review of pathology reports, using a regional mesothelioma registry and an older pathology archive, and comparing reports with published guidelines
• Who was studied: 819 pathology reports (753 histology, 66 cytology) of a first diagnosis of malignant pleural mesothelioma made in pathology departments of hospitals in the Lazio Region, Italy. Sources were the regional Mesothelioma Registry (2001–2014) and a pathology archive (1990–2000). Patients were 576 men (70.3%) and 243 women (29.7%). 120 pathologists signed the reports.
• Main results:
  • Across all 819 reports, average report completeness was 74.2%, ranging from 54.5% to 100%
  • The items most often missing were clinical history and/or queries (not provided in 625 reports, 76.3%), tumor laterality (502, 61.3%) and specimen size (308, 37.6%), according to Table 1
  • Histological subtype was not given in 23% of reports (187 of 819, 22.8%, in Table 1)
  • IHC was performed in 86% of reports overall (705 of 819). The proportion was 90% for epithelioid, 87% for biphasic and sarcomatoid, and 74% for unspecified histology
  • The mean number of stains per diagnosis was 7.02 for biphasic, 6.39 for sarcomatoid, 6.01 for epithelioid and 4.83 for unspecified histology. The difference was reported as statistically significant (Kruskal-Wallis test). The overall mean was 5.89 stains per diagnosis.
  • Use of uncertain wording (modifiers) with the term 'malignant mesothelioma' fell from 32% of reports before 2007 to 25% after (p = 0.017)
  • The compliance analysis for epithelioid mesothelioma covered 445 epithelioid cases with IHC, out of 493 epithelioid diagnoses in Table 1. Of these 445, 264 (59.3%; 59% in the text) used at least 2 positive and 2 negative mesothelioma markers, as guidelines recommend. In large-volume institutions (50 or more reports) compliance was 63%.
  • Among the epithelioid cases with IHC, compliance went from 62% before 2007 to 57% after. The difference was not statistically significant (p = 0.168).
  • The compliance analysis for sarcomatoid mesothelioma covered 66 sarcomatoid cases with IHC, out of 76 sarcomatoid diagnoses in Table 1. Of these 66, 7 (10.6% in Table 4; 10% in the text) used the recommended multiple cytokeratins plus at least 2 positive markers. Most (65%) were confirmed using a single cytokeratin plus one or more positive markers.
  • The share of reports without IHC fell from 20% before 2007 to 8.5% after
  • Stains for breast, prostate or melanoma markers were mentioned in 39 reports, and none was positive
• The authors' conclusion: The authors concluded that first-diagnosis pathology reports of malignant mesothelioma vary widely in how closely they follow current diagnostic guidelines and reporting recommendations. They said current guidelines need to be applied and that synoptic (structured) reporting could help standardize the diagnosis.
• Limitations the authors state:
  • The diagnoses were not centrally reviewed to confirm they were accurate
  • Some tumors with unexpected stain results might not have been true mesotheliomas, but the study did not re-evaluate diagnoses
  • The study covered one region and did not evaluate reporting throughout Italy
  • Several items were missing because the surgeons had not supplied the information

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pathology, Pleural Mesothelioma, Pathology Report, Mesothelioma, Immunohistochemistry, Epithelioid, Sarcomatoid, Histology.

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