Pseudomesotheliomatous carcinomas (PMC) are rare tumors that clinically, macroscopically, and sometimes histologically resemble malignant pleural mesotheliomas. We report a case of a 91 year woman who was found to have diffuse nodular pleural thickening and a lung mass during a workup for persistent cough. She declined rapidly and died before a histologic diagnosis could be made. Postmortem examination revealed a tumor that diffusely involved the pleural surface with local extension into the chest wall, pericardium, and diaphragm along with a concurrent lung mass. Histologic examination showed poorly-differentiated cells predominantly arranged in sheets, cords, and nests with focal glandular differentiation. An immunohistochemical panel of calretinin, WT1, BEREP4, MOC31, and TTF1 confirmed the diagnosis of primary lung adenocarcinoma. The macroscopic, histologic, and immunohistochemical features used to distinguish metastatic and primary lung adenocarcinoma from epithelioid malignant mesothelioma are discussed. The distinction of malignant mesothelioma from pseudomesotheliomatous carcinoma is important for medicolegal reasons regarding asbestos related compensation claims.
This is a preview of subscription content, log in to check access.
Martin Ishikawa, M.D. for serving as a consultant during the autopsy prosection.
Compliance with ethical standards
Conflict of interest
The author has no conflicts of interest to report.
The article does not contain any studies with human participants or animals.
The article does not include participants that require their informed consent.
Travis W, Brambilla E, Burke AP, Marx A, Nicholson AG. WHO classification of tumors of the lung, pleura, thymus, and heart. 4th ed. Lyon: International Agency for Research on Cancer; 2015. p. 161.Google Scholar
Attanoos RL, Gibbs AR. 'Pseudomesotheliomatous' carcinomas of the pleura: a 10-year analysis of cases from the Environmental Lung Disease Research Group, Cardiff. Histopathology. 2003;43:444–52.CrossRefGoogle Scholar
Hammar SP, Dodson RF. Pseudomesotheliomatous lung carcinoma: a pathological assessment of selected cases including the work history and presence of biomarkers suggesting it is a cancer caused by asbestos. Pathol Discov. 2015;3:6.CrossRefGoogle Scholar
Koss MN, Fleming M, Przygodzki RM, Sherrod A, Travis W, Hochholzer L. Adenocarcinoma simulating mesothelioma: a clinicopathologic and immunohistochemical study of 29 cases. Ann Diagn Pathol. 1998;2:93–102.CrossRefGoogle Scholar
Shah IA, Salvatore JR, Kummet T, Gani OS, Wheeler LA. Pseudomesotheliomatous carcinoma involving pleura and peritoneum: a clinicopathologic and immunohistochemical study of three cases. Ann Diagn Pathol. 1999;3:148–59.CrossRefGoogle Scholar
Pardo J, Torres W, Martinez-Penuela A, Panizo A, de Alava E, Garcia JL. Pseudomesotheliomatous carcinoma of the lung with a distinct morphology, immunohistochemistry, and comparative genomic hybridization profile. Ann Diagn Pathol. 2007;11:241–51.CrossRefGoogle Scholar
Rossini M, Rizzo P, Bononi I, Clementz A, Ferrari R, Martini F, et al. New perspectives on diagnosis and therapy of malignant pleural mesothelioma. Front Oncol. 2018;8:91.CrossRefGoogle Scholar
Arif Q, Husain AN. Malignant mesothelioma diagnosis. Arch Pathol Lab Med. 2015;139:978–80.CrossRefGoogle Scholar
Husain AN, Colby TV, Ordonez NG, Allen TC, Attanoos RL, Beasley MB, et al. Guidelines for pathologic diagnosis of malignant mesothelioma 2017 update of the consensus statement from the International Mesothelioma Interest Group. Arch Pathol Lab Med. 2018;142:89–108.CrossRefGoogle Scholar
van der Bij S, Baas P, van de Vijver MJ, de Mol BA, Burgers JA. Legal claims for malignant mesothelioma: dealing with all cases. Lung Cancer. 2013;80:153–8.CrossRefGoogle Scholar
Attanoos RL, Thomas DH, Gibbs AR. Synchronous diffuse malignant mesothelioma and carcinomas in asbestos-exposed individuals. Histopathology. 2003;43:387–92.CrossRefGoogle Scholar
Kadota K, Suzuki K, Sima CS, Rusch VW, Adusumilli PS, Travis WD. Pleomorphic epithelioid diffuse malignant pleural mesothelioma: a clinicopathological review and conceptual proposal to reclassify as biphasic or sarcomatoid mesothelioma. J Thoracic Oncol. 2011;6:896–904.CrossRefGoogle Scholar
Churg A, Sheffield BS, Galateau-Sall’e F. New markers for separating benign from malignant mesothelial proliferations: are we there yet? Arch Pathol Lab Med. 2016;140:318–21.CrossRefGoogle Scholar
Baumann F, Flores E, Napolitano A, et al. Mesothelioma patients with germline BAP1 mutations have 7-fold improved long-term survival. Carcinogenesis. 2015;36:76–81.CrossRefGoogle Scholar
Graham MA, Roggli VL. Medicolegal aspects of asbestos I — malignant mesothelioma and lung cancer. Academic Forensic Pathol. 2013;3:386–406.CrossRefGoogle Scholar