Localized malignant mesothelioma, an unusual and poorly characterized neoplasm of serosal origin: best current evidence from the literature and the International Mesothelioma Panel

EURACAN/IASLC Proposals for Updating the Histologic Classification of Pleural Mesothelioma: Towards a More Multidisciplinary Approach

“…Although rare, localized mesotheliomas are important to recognize as they are potentially treatable by complete (pR0) resection and carry a favorable prognosis compared to diffuse mesotheliomas. 5,6 Classification requires correlation with imaging and surgical findings to ensure that there is no evidence of unsampled diffuse disease. Localized mesotheliomas have been shown to have distinctive genetic features, with both similarities to and differences from diffuse MPM.…”

“…Results: Recommendations include: (1) classification should be updated to include architectural patterns and stromal and cytologic features that refine prognostication; (2) subject to data accrual, malignant mesothelioma in situ could be an additional category; (3) grading of epithelioid malignant pleural mesotheliomas should be routinely undertaken; (4) favorable/unfavorable histologic characteristics should be routinely reported; (5) clinically relevant molecular data (programmed death ligand 1, BRCA 1 associated protein 1 [BAP1], and cyclin dependent kinase inhibitor 2A) should be incorporated into reports, if undertaken; (6) other molecular data should be accrued as part of future trials; (7) resection specimens (i.e., extended pleurectomy/decortication and extrapleural pneumonectomy) should be pathologically staged with smaller specimens being clinically staged; (8) ideally, at least three separate areas should be sampled from the pleural cavity, including areas of interest identified on pre-surgical imaging; (9) image-acquisition protocols/imaging terminology should be standardized to aid research/ refine clinical staging; (10) multidisciplinary tumor boards should include pathologists to ensure appropriate treatment options are considered; (11) all histologic subtypes should be considered potential candidates for chemotherapy; (12) patients with sarcomatoid or biphasic mesothelioma should not be excluded from first-line clinical trials unless there is a compelling reason; (13) tumor subtyping should be further assessed in relation to duration of response to immunotherapy; and (14) systematic screening of all patients for germline mutations is not recommended, in the absence of a family history suspicious for BAP1 syndrome.…”

Update on Diagnosing and Reporting Malignant Pleural Mesothelioma

“…Retrospective cohorts drawn from large multi-institutional data sets consistently show the longest overall survivals in patients with epithelioid histology, the shortest survivals in those with sarcomatoid MPM, and intermediate survival in patients with biphasic MPM (8). Truly localized mesotheliomas are extremely rare, show the same range of histologic subtypes, and are affiliated with better survivals given the possibility of complete surgical excision (9).…”

A Literature Review of Localized Mediastinal Mesothelioma and a Rare Case Report

“…Localized (solitary) pericardial mesothelioma is considered a rare variant of MPM. In 2002, J.Fernando et al [12] reviewed only 4 cases in the literature, and S.Cao et al [13] reported 8 cases in 2017, an increase of 4 cases compared with before. Marchevsky et al [14] reviewed 101 cases of localized mesothelioma reported in the English literature before July 2019, which did not show an increase in the number of cases of mediastinal mesothelioma.…”