1
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Hung YP, Chirieac LR. Molecular and Immunohistochemical Testing in Mesothelioma and Other Mesothelial Lesions. Arch Pathol Lab Med 2024; 148:e77-e89. [PMID: 38190277 DOI: 10.5858/arpa.2023-0213-ra] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2023] [Indexed: 01/10/2024]
Abstract
CONTEXT.— Molecular testing has increasingly been utilized in the evaluation of mesothelioma. Diffuse mesothelioma comprises multiple distinct genetic subgroups. While most diffuse mesotheliomas lack oncogenic kinase mutations and instead harbor alterations involving tumor suppressors and chromatin regulators, a minor subset of tumors is characterized by uncommon alterations such as germline mutations, genomic near-haploidization, ALK rearrangement, ATF1 rearrangement, or EWSR1::YY1 fusion. OBJECTIVE.— To provide updates on the salient molecular features of diffuse mesothelioma, mesothelioma in situ, and other mesothelial lesions: well-differentiated papillary mesothelial tumor, adenomatoid tumor, peritoneal inclusion cyst, and others. We consider the diagnostic, prognostic, and predictive utility of molecular testing in mesothelial lesions. DATA SOURCES.— We performed a literature review of recently described genetic features, molecular approaches, and immunohistochemical tools, including BAP1, MTAP, and merlin in mesothelioma and other mesothelial lesions. CONCLUSIONS.— Our evolving understanding of the molecular diversity of diffuse mesothelioma and other mesothelial lesions has led to considerable changes in pathology diagnostic practice, including the application of immunohistochemical markers such as BAP1, MTAP, and merlin (NF2), which are surrogates of mutation status. In young patients and/or those without significant asbestos exposure, unusual mesothelioma genetics such as germline mutations, ALK rearrangement, and ATF1 rearrangement should be considered.
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MESH Headings
- Humans
- Mesothelioma/diagnosis
- Mesothelioma/genetics
- Mesothelioma/metabolism
- Mesothelioma/pathology
- Immunohistochemistry
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Biomarkers, Tumor/analysis
- Neoplasms, Mesothelial/diagnosis
- Neoplasms, Mesothelial/genetics
- Neoplasms, Mesothelial/metabolism
- Neoplasms, Mesothelial/pathology
- Mesothelioma, Malignant/diagnosis
- Mesothelioma, Malignant/genetics
- Mesothelioma, Malignant/pathology
- Mesothelioma, Malignant/metabolism
- Mutation
- Tumor Suppressor Proteins
- Ubiquitin Thiolesterase
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Affiliation(s)
- Yin P Hung
- From the Department of Pathology, Massachusetts General Hospital. Boston (Hung)
- the Department of Pathology, Harvard Medical School, Boston, Massachusetts (Hung, Chirieac)
| | - Lucian R Chirieac
- the Department of Pathology, Harvard Medical School, Boston, Massachusetts (Hung, Chirieac)
- the Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts (Chirieac)
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2
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Mizuhashi K, Okamoto K, Nabeshima K, Kishimoto T. Detailed clinical course of a patient with rapidly progressing sarcomatoid pleural mesothelioma without p16 deletion with systemic haematogenous metastasis to soft tissues. BMJ Case Rep 2024; 17:e257618. [PMID: 38341199 PMCID: PMC10862345 DOI: 10.1136/bcr-2023-257618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024] Open
Abstract
Sarcomatoid mesothelioma is difficult to differentiate from other mesotheliomas. Here, we describe the case of a man in his early 80s with sarcomatoid mesothelioma and a history of asbestos exposure. He initially presented with right-sided chest pain and was examined. Right-sided pleural effusion was detected; therefore, he was hospitalised. Based on the observed pleural effusion and biopsy result, the presence of a malignant tumour was excluded; hence, he was diagnosed with benign asbestos pleurisy. He subsequently developed left-sided pleural effusion, masses and lung nodules, and died 9.5 months after the initial examination. A definitive diagnosis of sarcomatoid mesothelioma with rapid systemic progression was established after detailed investigations using autopsy specimens. This rare case of mesothelioma-without p16 deletion (detected using fluorescence in situ hybridisation)-presented differently from the usual sarcomatoid mesothelioma.
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Affiliation(s)
| | - Kenzo Okamoto
- Hokkaido Chuo Rosai Hospital, Iwamizawa, Hokkaido, Japan
| | | | - Takumi Kishimoto
- Research and Training Center for Asbestos-Related Disease, Okayama, Japan
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3
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Symes E, Tjota M, Cody B, Kindler H, Mitchell O, Witmer H, Turaga K, Mueller J, Krausz T, Husain AN, Li H. Mesothelioma in situ of the peritoneum: report of three cases and review of the literature. Histopathology 2024; 84:492-506. [PMID: 38084880 DOI: 10.1111/his.15092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/29/2023] [Accepted: 10/15/2023] [Indexed: 01/10/2024]
Abstract
AIM Diagnosis of mesothelioma in situ (MIS) is historically controversial and, until recently, specific features defining the entity have not been well characterized. Most reported cases of MIS occurred in the pleura; peritoneal MIS is very rare. This study investigates the morphologic features and results of ancillary testing in peritoneal MIS. METHODS We present three patients with peritoneal MIS, as defined by a single layer of mesothelial cells with loss of nuclear BRCA-1-associated protein-1 (BAP1) immunostaining and without evidence of invasive tumour by microscopic evaluation, imaging, or direct examination of the peritoneum. Histology and immunostains were reviewed by three expert thoracic pathologists with multidisciplinary input. Next-generation sequencing (NGS) was performed in all three cases. A literature review was conducted to characterize this rare precursor lesion. RESULTS BAP1 was lost in all three lesions, while methylthioadenosine phosphorylase (MTAP) was retained in two (not performed in the third). NGS revealed BAP1 pathogenic alterations in all three cases as well as mutations of SMO, ERCC3, TET2, and U2AF1. Progression to invasive mesothelioma occurred in one patient at 13 months postdiagnosis (case 1). One patient was diagnosed at age 24 and was later found to harbour a BAP1 germline mutation (case 3). CONCLUSION This work describes the histologic features and clinicopathologic characteristics of peritoneal MIS in three cases, highlights BAP1 somatic and germline mutations in peritoneal MIS, and strengthens the importance of ancillary studies (including immunohistochemical and molecular studies) in the diagnosis of MIS.
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Affiliation(s)
- Emily Symes
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Melissa Tjota
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Brittany Cody
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Hedy Kindler
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, USA
| | | | - Hunter Witmer
- Department of Surgery, University of Chicago, Chicago, IL, USA
| | - Kiran Turaga
- Department of Surgery, University of Chicago, Chicago, IL, USA
- Department of Surgery, Yale Cancer Center, New Haven, CT, USA
| | - Jeffrey Mueller
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Thomas Krausz
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Aliya N Husain
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Huihua Li
- Department of Pathology, University of Chicago, Chicago, IL, USA
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
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Yoshida M, Jimbo N, Tsukamoto R, Itoh T, Kawahara K, Mitsui S, Tanaka Y, Maniwa Y. Sarcomatoid mesothelioma diagnosed in a patient with mesothelioma in situ: a case report on morphologic differences after 9-month interval with details analysis of cytology in early-stage mesothelioma. Diagn Pathol 2023; 18:126. [PMID: 38017544 PMCID: PMC10683101 DOI: 10.1186/s13000-023-01416-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/16/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND Overlapping morphological features of mesothelial cells have been rendered it difficult to distinguish between reactive and malignant conditions. The development of methods based on detecting genomic abnormalities using immunohistochemistry and fluorescence in situ hybridization have contributed markedly to solving this problem. It is important to identify bland mesothelioma cells on cytological screening, perform efficient genomic-based testing, and diagnose mesothelioma, because the first clinical manifestation of pleural mesothelioma is pleural effusion, which is the first sample available for pathological diagnosis. However, certain diagnostic aspects remain challenging even for experts. CASE PRESENTATION This report describes a case of a 72-year-old man with a history of asbestos exposure who presented with pleural effusion as the first symptom and was eventually diagnosed as mesothelioma. Mesothelioma was suspected owing to prominent cell-in-cell engulfment in mesothelial cells on the first cytological sample, and the diagnosis of mesothelioma in situ was confirmed by histology. Unexpectedly, sarcomatoid morphology of mesothelioma was found in the second pathology samples 9 months after the first pathological examination. Both the mesothelioma in situ and invasive lesion showed immunohistochemical loss of methylthioadenosine phosphorylase (MTAP) and homozygous deletion of cyclin dependent kinase inhibitor 2A (CDKN2A) on fluorescence in situ hybridization. The patient received medication therapy but died of disease progression 12 months after the diagnosis of the sarcomatoid morphology of mesothelioma. CONCLUSION Our case suggests that cell-in-cell engulfment can be conspicuous in early-stage mesothelioma with inconspicuous nuclear atypia and few multinucleated cells. In addition, the presence of MTAP loss and CDKN2A homozygous deletion are suspected to be involved in early formation to invasive lesions and/or sarcomatoid morphology. We believe that it is important to consider genetic abnormalities when deciding on individual patient management. Furthermore, cases of mesothelioma, even those of an in situ lesion, with MTAP loss and/or CDKN2A deletion should be carefully followed up or subjected to early treatment.
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Affiliation(s)
- Miho Yoshida
- Department of Diagnostic Pathology, Kobe University Hospital, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Naoe Jimbo
- Department of Diagnostic Pathology, Kobe University Hospital, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan.
| | - Ryuko Tsukamoto
- Department of Diagnostic Pathology, Kobe University Hospital, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Tomoo Itoh
- Department of Diagnostic Pathology, Kobe University Hospital, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Kunimitsu Kawahara
- Division of Pathology for Regional Communication, Kobe University Graduate School of Medicine, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Suguru Mitsui
- Division of Thoracic Surgery, Kobe University Graduate School of Medicine, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Yugo Tanaka
- Division of Thoracic Surgery, Kobe University Graduate School of Medicine, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
| | - Yoshimasa Maniwa
- Division of Thoracic Surgery, Kobe University Graduate School of Medicine, Address: 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan
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5
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Michael CW, Bedrossian CCWM, Sadri N, Klebe S. The cytological features of effusions with mesothelioma in situ: A report of 9 cases. Diagn Cytopathol 2023; 51:374-388. [PMID: 36942732 DOI: 10.1002/dc.25129] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/16/2023] [Accepted: 03/03/2023] [Indexed: 03/23/2023]
Abstract
INTRODUCTION The diagnosis of mesothelioma in situ (MIS) is now accepted by the WHO as a pre-invasive neoplastic mesothelial proliferation and considered a diagnosis based on histologic evaluation only. Although the definition of MIS includes recurrent effusions, little is known about the cytologic features of such effusions. Since mesothelioma is usually diagnosed at an advanced stage and has a poor prognosis, early detection of a neoplastic mesothelial population in such effusions can potentially have a positive impact on the management of such a dire disease. MATERIALS AND METHODS We reviewed a total of 18 pleural effusions from nine patients with recurrent effusions. Of these, five patients had follow-up biopsies diagnosed as MIS and the remaining four cases had negative radiology and malignant cytology proven by molecular markers (BAP1, MTAP or CDKN2A deletion) and at least 1 year follow-up with no overt mass identified by radiology. RESULTS Initial effusions may mimic reactive mesothelial hyperplasia or exhibit atypia. As effusions recur, the cellularity and atypia increase and the mesothelial proliferation becomes morphologically indistinguishable from mesothelioma. Molecular alterations diagnostic of mesothelioma can be detected in these effusions, even in the initial-benign/reactive appearing ones. The cellularity and atypia detected in such effusions surpassed those noted on the biopsies, raising questions regarding the cause of such discrepancy. CONCLUSION The diagnosis of MIS can be suspected based on malignant effusion cytology supported by molecular alterations. We propose that the proliferation of neoplastic mesothelial clones represent a clinically silent "liquid phase MIS stage" corresponding to in situ stage in other organs.
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Affiliation(s)
- Claire W Michael
- Department of Pathology, University Hospitals Cleveland Medical Center/Case Western Reserve University, USA
| | | | - Navid Sadri
- Department of Molecular Diagnostics, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sonja Klebe
- Department of Pathology, Flinders University and SA Pathology, Adelaide, South Australia, Australia
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New Insights in Pleural Mesothelioma Classification Update: Diagnostic Traps and Prognostic Implications. Diagnostics (Basel) 2022; 12:diagnostics12122905. [PMID: 36552912 PMCID: PMC9776784 DOI: 10.3390/diagnostics12122905] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/05/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
The 2021 WHO Classification of Tumors of the Pleura has introduced significant changes in mesothelioma codification beyond the three current histological subtypes-epithelioid, sarcomatoid and biphasic. Major advances since the 2015 WHO classification include nuclear grading and the introduction of architectural patterns, cytological and stromal features for epithelioid diffuse mesothelioma. Mesothelioma in situ has been recognized as a diagnostic category. Demonstration of loss of BAP1 or MTAP by immunohistochemistry, or CDKN2A homozygous deletion by FISH, is valuable in establishing the diagnosis of epithelioid mesothelioma. Recent emerging data proved that grading and histological subtypes have prognostic implications and may be helpful to patient risk stratification and clinical management. Nevertheless, the latest mesothelioma classification increases the already non-negligible diagnostic pitfalls, especially concerning differential diagnosis of pre-invasive tumors. In this review, recent changes in histologic classification of mesothelioma and advances in molecular markers are presented and their relation to diagnostic challenges and prognostic implications is discussed.
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7
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Well differentiated papillary mesothelial tumor: a new name and new problems. Mod Pathol 2022; 35:1327-1333. [PMID: 35440764 DOI: 10.1038/s41379-022-01082-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/13/2022] [Accepted: 03/28/2022] [Indexed: 11/09/2022]
Abstract
Well-differentiated papillary mesothelial tumor (WDPMT, formerly called well-differentiated papillary mesothelioma) is a morphologically distinctive lesion composed of expansile papillae with a myxoid core covered by a single layer of generally bland mesothelial cells. Whether some WDPMT are precursors of invasive mesothelioma is uncertain, and this question is confounded by shallow biopsies of ordinary diffuse mesotheliomas that have superficial areas resembling WDPMT as well as by misinterpretation of some cases of mesothelioma in situ. Genetic analyses on a very small number of published cases of peritoneal WDPMT have shown a variety of mutations/copy number losses that do not overlap at all with those that are found recurrently in invasive mesotheliomas. The newly described entity of mesothelioma in situ usually appears as a single layer of mesothelial cells that have lost BAP1 by immunostaining, but sometimes is papillary and produces a morphologic mimic of WDPMT. We propose that, at least in the peritoneal cavity where most WDPMT occur, there are two morphologically identical but functionally distinct lesions: one is true WDPMT, a process that is probably benign, and the other is papillary mesothelioma in situ with the configuration of WDPMT. For that reason immunostaining for BAP1, and if necessary MTAP or CDKN2A FISH, should always be performed on cases with the appearance of WDPMT. It is possible, but speculative, that the small number of reports in the literature which describe invasive mesothelioma arising from WDMPT are actually describing invasive mesothelioma arising from mesothelioma in situ that looks like WDPMT.
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8
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Sneaky Diagnosis of Pleural Malignant Mesothelioma in Thoracic Surgery: All That Glitters Is Not Gold. J Clin Med 2022; 11:jcm11113225. [PMID: 35683612 PMCID: PMC9181256 DOI: 10.3390/jcm11113225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 11/17/2022] Open
Abstract
Malignant Pleural Mesothelioma (MPM) is a highly aggressive disease whose diagnosis could be challenging and confusing. It could occur with atypical presentations on every examined level. Here, we present three unconventional cases of the complex diagnostic process of MPM that we have experienced during routine practice: a patient with reactive mesothelial hyperplasia mimicking MPM, an unexpected presentation of MPM with persistent unilateral hydropneumothorax, a rare case of MPM in situ. Then, we review the relevant literature on each of these topics. Definitive biomarkers to confidently distinguish MPM from other pleural affections are still demanded. Patients presenting with persistent hydropneumothorax must always be investigated for MPM. MPM in situ is now a reality, and this raises questions about its management.
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Nabeshima K, Hamasaki M, Kinoshita Y, Matsumoto S, Sa-Ngiamwibool P. Update of pathological diagnosis of pleural mesothelioma using genomic-based morphological techniques, for both histological and cytological investigations. Pathol Int 2022; 72:389-401. [PMID: 35596704 DOI: 10.1111/pin.13235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/28/2022] [Indexed: 11/30/2022]
Abstract
As more than 80% of pleural mesothelioma (PM) cases start with pleural effusions, diagnosis with effusion smear cytology or pleural biopsy is important. For diagnosing PM, a three-step approach is used: (1) detecting atypical cells; (2) verifying their mesothelial origin using immunohistochemistry (IHC); and (3) discriminating PM from benign mesothelial proliferations (BMP). The third step is critical for diagnosing early lesions. In small biopsy or cytologic specimens in which tumor cell fat invasion cannot be assessed, genomic-based assays, including IHC-detected BAP1 loss and fluorescence in situ hybridization (FISH)-detected homozygous deletion (HD) of CDKN2A/p16, are effective for differentiation. Both BAP1 IHC and CDKN2A FISH can equally be applied to histologic and cytologic specimens, with 100% specificity in discriminating PM from BMP. We found that methylthioadenosine phosphorylase (MTAP) loss as detected by IHC could serve as a feasible alternative in tissue and cytologic preparations for CDKN2A FISH. However, a combination including FISH was still most effective: the addition of NF2 FISH to CDKN2A FISH and BAP1 IHC yielded a greater sensitivity of close to 100% in diagnosing PM tissues. Although IHC is more feasible than FISH, owing to remaining challenges in data interpretation, caution and familiarity are warranted when diagnosing PM.
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Affiliation(s)
- Kazuki Nabeshima
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Makoto Hamasaki
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Yoshiaki Kinoshita
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Shinji Matsumoto
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Prakasit Sa-Ngiamwibool
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan.,Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kean, Thailand
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10
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Sarcomatoid mesothelioma originating from mesothelioma in situ: are methylthioadenosine phosphorylase loss and CDKN2A homozygous deletion poor prognostic factors for preinvasive mesothelioma? Virchows Arch 2022; 481:307-312. [PMID: 35043235 DOI: 10.1007/s00428-022-03281-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/06/2022] [Accepted: 01/13/2022] [Indexed: 10/19/2022]
Abstract
The diagnosis of mesothelioma in situ (MIS) is challenging with conventional diagnostic approaches. Although recent advances in genomic-based assays have made it possible to diagnose MIS, the prognosis, treatment indications, and prognostic factors remain unclear. Previous reports have shown that MIS progresses to invasive mesothelioma; however, to the best of our knowledge, progression to sarcomatoid mesothelioma has not yet been reported. A 73-year-old man was diagnosed with MIS associated with methylthioadenosine phosphorylase (MTAP) loss and a CDKN2A homozygous deletion. Strikingly, pathological examination revealed that the MIS lesion had progressed to sarcomatoid mesothelioma. In analyses of previously reported cases and our case, MIS with a CDKN2A homozygous deletion or MTAP loss progressed to invasive mesothelioma earlier than that without them, indicating that a CDKN2A homozygous deletion and MTAP loss could be poor prognostic factors. Genomic analyses might be useful for predicting the prognosis of MIS and contributing to an optimal treatment.
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11
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Sauter JL, Dacic S, Galateau-Salle F, Attanoos RL, Butnor KJ, Churg A, Husain AN, Kadota K, Khoor A, Nicholson AG, Roggli V, Schmitt F, Tsao MS, Travis WD. The 2021 World Health Organization Classification of Tumors of the Pleura: Advances since the 2015 Classification. J Thorac Oncol 2022; 17:608-622. [PMID: 35026477 DOI: 10.1016/j.jtho.2021.12.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/14/2021] [Accepted: 12/31/2021] [Indexed: 12/01/2022]
Abstract
Significant changes in the 2021 World Health Organization (WHO) Classification of Tumors of the Pleura and Pericardium since the 2015 WHO Classification include: 1) Pleural and pericardial tumors have been combined in one chapter whereas in the 2015 WHO, pericardial tumors were classified with cardiac tumors; 2) Well-differentiated papillary mesothelioma (WDPM) has been renamed well-differentiated papillary mesothelial tumor (WDPMT) given growing evidence that these tumors exhibit relatively indolent behavior; 3) Localized and diffuse mesothelioma no longer include the term "malignant" as a prefix; 4) Mesothelioma in situ (MIS) has been added to the 2021 classification since these lesions can now be recognized by loss of BAP1 and/or MTAP by immunohistochemistry and/or CDKN2A homozygous deletion by FISH; 5) The three main histologic subtypes (i.e. epithelioid, biphasic and sarcomatoid) remain the same but architectural patterns, cytologic and stromal features are more formally incorporated into the 2021 classification based on their prognostic significance; 6) Nuclear grading for epithelioid diffuse mesothelioma is introduced and it is recommended to record this and other histologically prognostic features in pathology reports; 7) BAP1, EZH2 and MTAP immunohistochemistry have been shown to be useful in separating benign mesothelial proliferations from mesothelioma; 8) Biphasic mesothelioma can be diagnosed in small biopsies showing both epithelioid and sarcomatoid components even if the amount of one component is less than 10%; and 9) The most frequently altered genes in diffuse pleural mesothelioma include BAP 1, CDKN2A, NF2, TP53, SETD2 and SETB1.
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Affiliation(s)
- Jennifer L Sauter
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York, United States.
| | - Sanja Dacic
- Department of Pathology University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Francoise Galateau-Salle
- MESOPATH Centre Leon Berard, Lyon, France, Unit of Cancer Research Center INSERM U1052-CNRS5286R, Lyon France
| | - Richard L Attanoos
- Department of Cellular Pathology, University Hospital of Wales and School of Medicine, Cardiff University, Wales, United Kingdom
| | - Kelly J Butnor
- Department of Pathology & Laboratory Medicine, The University of Vermont Medical Center, Burlington, Vermont, United States
| | - Andrew Churg
- Dept of Pathology, Vancouver General Hospital and University of British Columbia, Vancouver, British Columbia, Canada
| | - Aliya N Husain
- Department of Pathology, University of Chicago, Chicago, Illinois, United States
| | - Kyuichi Kadota
- Department of Pathology, Faculty of Medicine, Shimane University
| | - Andras Khoor
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Jacksonville, Florida, United States
| | - Andrew G Nicholson
- Royal Brompton and Harefield Hospitals, and National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Victor Roggli
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States
| | - Fernando Schmitt
- RISE@Cintesis, Medical Faculty of Porto University, Porto, Portugal; Unit of Molecular Pathology of IPATIMUP, Porto, Portugal
| | - Ming-Sound Tsao
- Department of Pathology, University Health Network, Princess Margaret Cancer Centre, Toronto, Canada
| | - William D Travis
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York, United States
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12
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Pleural mesothelioma classification-update and challenges. Mod Pathol 2022; 35:51-56. [PMID: 34465883 DOI: 10.1038/s41379-021-00895-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022]
Abstract
Mesothelial tumors are classified into benign or preinvasive tumors, and mesotheliomas. The benign or preinvasive group includes adenomatoid tumors, well-differentiated papillary mesothelial tumors, and mesothelioma in situ. Malignant tumors are mesotheliomas and can be localized or diffuse. Histological classification of invasive mesotheliomas into three major subtypes-epithelioid, sarcomatoid, and biphasic is prognostically important. It also plays a significant role in the treatment decisions of patients diagnosed with this deadly disease. Grading and subtyping of epithelioid mesotheliomas have been one of the major changes in the recent WHO classification of pleural tumors. Mesothelioma in situ has emerged as a precisely defined clinico-pathologic entity that for diagnosis requires demonstration of loss of BAP1 or MTAP by immunohistochemistry, or CDKN2A homozygous deletion by FISH. The use of these two biomarkers improves the diagnostic sensitivity of effusion specimens and limited tissue samples and is valuable in establishing the diagnosis of epithelioid mesothelioma. In this review, recent changes in the histologic classification of pleural mesothelioma, importance of ancillary diagnostic studies, and molecular characteristics of mesotheliomas are discussed.
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13
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Klebe S. Progression of mesothelioma in situ to invasive disease 4 years and 10 months after initial diagnosis. Pathology 2021; 54:384-386. [PMID: 34565603 DOI: 10.1016/j.pathol.2021.06.124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/18/2021] [Accepted: 06/24/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Sonja Klebe
- Department of Anatomical Pathology, Flinders University and SA Pathology, Adelaide, SA, Australia.
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14
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Monaco SE, Brcic L, Dacic S. State-of-the-art cytology of pleural fluid, focusing on the diagnosis of mesothelioma. Cytopathology 2021; 33:57-64. [PMID: 34467576 DOI: 10.1111/cyt.13055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/02/2021] [Accepted: 08/23/2021] [Indexed: 12/18/2022]
Abstract
Mesothelioma has always been a challenging diagnosis to render in body cavity cytology samples. This review is a timely update on pleural fluid cytology and ancillary studies that should be considered in the diagnosis of mesothelial proliferations, specifically mesotheliomas. Information about new diagnostic approaches and ancillary studies in mesothelioma was obtained from the peer-reviewed literature and the authors' experiences. Although the morphological diagnosis of mesothelioma is fraught with numerous challenges given the overlap with other diagnostic entities, there are a variety of immunohistochemical and fluorescence in situ hybridization studies available to help in determining mesothelial origin and in distinguishing malignant proliferations from the more common benign or reactive mesothelial proliferations. Although ancillary studies can be helpful, there are important pitfalls to be aware of when interpreting these cases, and this review highlights some of the challenges that require caution.
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Affiliation(s)
- Sara E Monaco
- System Director of Cytopathology, Department of Laboratory Medicine, Geisinger Medical Center, Danville, PA, USA
| | - Luka Brcic
- Medical University of Graz Institute of Pathology, Graz, Austria
| | - Sanja Dacic
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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15
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The concept of mesothelioma in situ, with consideration of its potential impact on cytology diagnosis. Pathology 2021; 53:446-453. [PMID: 33775406 DOI: 10.1016/j.pathol.2020.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/14/2020] [Accepted: 12/18/2020] [Indexed: 12/24/2022]
Abstract
Diffuse malignant mesothelioma (MM) is an incurable tumour of the serosal membranes, which is often caused by exposure to asbestos and commonly diagnosed at advanced stage. Malignant mesothelioma in situ (MMIS) is now included as diagnostic category by the World Health Organization (WHO). However, our international survey of 34 pulmonary pathologists with an interest in MM diagnosis highlights inconsistency regarding how the diagnosis is being made by experts, despite published guidelines. Whilst the WHO restricts the diagnosis to surgical samples, the very concept has implication for cytological diagnosis, which is already regarded as controversial in itself by some. MMIS is currently only applicable as precursor to MM with an epithelioid component, and raises the possibility for different molecular pathways for different histological MM subtypes. The clinical implications of MMIS at this stage are uncertain, but aggressive therapies are being initiated in some instances. Based on the results of the survey we here present a critical appraisal of the concept, its clinical and conceptual implications and provide practice suggestions for diagnosis. A low threshold for ancillary testing is suggested. The designations of 'malignant mesothelioma, cannot exclude MMIS' or 'atypical mesothelial proliferation with molecular indicators of malignancy, so-called MMIS' could be used on cytology samples, adding 'no evidence of invasion in sample provided' for surgical samples. Clinical and radiological correlation are integral to diagnosis and best done at multidisciplinary meetings. Finally, collaborative studies are required to improve our understanding of MMIS.
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16
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Beasley MB, Galateau-Salle F, Dacic S. Pleural mesothelioma classification update. Virchows Arch 2021; 478:59-72. [PMID: 33475835 DOI: 10.1007/s00428-021-03031-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/23/2020] [Accepted: 01/11/2021] [Indexed: 12/17/2022]
Abstract
The 2015 WHO classification of pleural mesotheliomas includes three major histologic subtypes-epithelioid, sarcomatoid, and biphasic. Recent genomic data has supported the need for a more granular and clinically valid classification beyond the three current subtypes. Because of tumor rarity and overlapping histologic features with other tumor types, diagnostic immunohistochemical work up is essential component in establishing the final diagnosis of mesothelioma. The use of BAP1 and CDKN2A/MTAP improves the diagnostic sensitivity of effusion specimens and are valuable in establishing the diagnosis of epithelioid mesothelioma. The major change in the forthcoming WHO classification is the inclusion of mesothelioma in situ as a diagnostic category. In this review, we discuss recently proposed changes in the histologic classification of pleural mesothelioma, differential diagnosis, and importance of ancillary diagnostic studies.
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Affiliation(s)
- Mary Beth Beasley
- Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Sanja Dacic
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, 15213, USA.
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17
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The Separation of Benign and Malignant Mesothelial Proliferations: New Markers and How to Use Them. Am J Surg Pathol 2020; 44:e100-e112. [PMID: 32826526 DOI: 10.1097/pas.0000000000001565] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The separation of benign from malignant mesothelial proliferations is an important clinical but often a difficult morphologic problem. Over the last roughly 10 years a variety of new markers that aid in this separation have been published and some older recommended markers reconsidered. Unlike previous, and largely unusable, empiric immunohistochemical (IHC) stains, these new markers, some using IHC and some using fluourescent in situ hybridization (FISH), are largely based on documented genomic abnormalities in malignant mesotheliomas. However, no marker works in all situations; rather, markers need to be chosen by the morphology of the process in question (epithelial vs. spindled) and the body cavity of interest (pleural vs. peritoneal). It is also important to be familiar with the exact pattern, for example nuclear versus cytoplasmic loss, that indicates a positive test. Furthermore, no single marker is 100% sensitive even with the optimal morphology/location, so that combinations of markers are essential. This review covers the various new markers in the literature, highlights their advantages and limitations, and suggests morphology/site specific combinations that can produce sensitivities in the 80% to 90% (and perhaps higher) range. At present only BRCA-1 related protein-1 and methylthioadenosine phosphorylase IHC, and cyclin-dependent kinase inhibitor 2A (p16) FISH have sufficient publications and reproducibility of results to be considered as established markers. 5-Hydroxymethyl cytosine, enhancer of zeste homolog 2, cyclin D1, and programmed death-ligand 1 IHC, and NF2 FISH are all potentially useful but need further study. The newly described entity of malignant mesothelioma in situ sits at the interface of benign and malignant mesothelial process; criteria for this diagnosis are reviewed.
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18
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Hidaka K, Takeda T, Kinoshita Y, Nabeshima K, Tamiya S, Yoshikawa Y, Tsujimura T. Development of mesothelioma in situ and its progression to invasive disease observed in a patient with uncontrolled pleural effusions for 15 years. Pathol Int 2020; 70:1009-1014. [PMID: 32956524 DOI: 10.1111/pin.13021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/11/2020] [Accepted: 08/26/2020] [Indexed: 10/23/2022]
Abstract
Mesothelioma in situ (MIS) has recently been investigated as a distinct phase of mesothelioma carcinogenesis. The diagnostic criteria proposed for MIS include a loss of BRCA1-associated protein 1 (BAP1) expression detected by immunohistochemistry (IHC). However, the length of time that MIS typically remains an in situ lesion before progression to invasive disease is still unclear. Herein, we report a case of a Japanese woman in her early seventies who had suffered from recurrent pleural effusions for 15 years, during which MIS developed and progressed to invasive mesothelioma. Retrospective diagnosis of partial MIS, fully developed MIS, and invasive disease was made using BAP1 IHC on three biopsy specimens and via clinical observations with radiological images. MIS and invasive lesions revealed BAP1 loss. The interval from partial or full MIS to invasive disease was 14 and 7 years, respectively. These results support a diagnostic strategy combining histomorphology with genomic-based assays including BAP1 IHC in biopsy tissues from a patient with recurrent pleural effusions.
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Affiliation(s)
- Kouko Hidaka
- Division of Respiratory Medicine, Department of Internal Medicine, National Institutional Hospital, Kokura Medical Center, Fukuoka, Japan
| | - Tetsushi Takeda
- Division of Respiratory Medicine, Department of Internal Medicine, National Institutional Hospital, Kokura Medical Center, Fukuoka, Japan
| | - Yoshiaki Kinoshita
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Kazuki Nabeshima
- Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan
| | - Sadafumi Tamiya
- Department of Pathology, Kitakyushu Municipal Medical Center, Fukuoka, Japan
| | | | - Tohru Tsujimura
- Department of Pathology, Hyogo College of Medicine, Hyogo, Japan
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19
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Dacic S, Roy S, Lyons MA, von der Thusen JH, Galateau-Salle F, Churg A. Whole exome sequencing reveals BAP1 somatic abnormalities in mesothelioma in situ. Lung Cancer 2020; 149:1-4. [PMID: 32932212 DOI: 10.1016/j.lungcan.2020.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/19/2020] [Accepted: 09/01/2020] [Indexed: 12/23/2022]
Abstract
OBJECTIVES We have recently described the first cases of mesothelioma in situ, identified as a pure surface population of mesothelial cells that have lost BAP1 nuclear staining, in the setting of no clinically/radiologically demonstrable mesothelial tumor. These cases have a high propensity to develop invasive mesothelioma. The genetic events that lead to the development of mesothelioma in situ are unknown, nor is it known whether mesothelioma in situ cases carry somatic or germline mutations. MATERIAL AND METHODS Whole exome sequencing (WES) was performed on two cases of mesothelioma in situ (1 pleural, 1 peritoneal) and paired formalin fixed paraffin embedded normal tissue to characterize driver mutations and copy number alterations. RESULTS The analysis demonstrated somatic alterations in the BAP1 gene only. The pleural mesothelioma in situ showed copy number loss and LOH in the BAP1 locus on chromosome 3. The peritoneal mesothelioma in situ showed both a BAP1 somatic splice site mutation involving intron 5-exon 6 boundary (A126_splice) with an allelic fraction of 10%, and BAP1 copy number loss. No other driver point mutations, indels or somatic DNA copy number alterations reported to occur in invasive mesothelioma, or novel genetic alterations, were identified. CONCLUSION Whole exome sequencing confirms that mesothelioma in situ development is associated with BAP1 somatic mutations/deletions, and suggests that BAP1 mutation/deletion represents a very early event in the development of malignant mesothelioma. Whether BAP1 mutation/deletion alone is sufficient to lead to invasive mesothelioma or whether additional genetic alterations are required remains to be determined.
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Affiliation(s)
- Sanja Dacic
- Department of Pathology University of Pittsburgh, PA, United States.
| | - Somak Roy
- Department of Pathology University of Pittsburgh, PA, United States
| | - Maureen A Lyons
- Department of Pathology University of Pittsburgh, PA, United States; UPMC Hillman Cancer Center, Shadyside Hospital, Pittsburgh, PA, United States
| | | | | | - Andrew Churg
- Department of Pathology, Vancouver General Hospital and University of British Columbia, Vancouver, BC, Canada
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20
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Chevrier M, Monaco SE, Jerome JA, Galateau-Salle F, Churg A, Dacic S. Testing for BAP1 loss and CDKN2A/p16 homozygous deletion improves the accurate diagnosis of mesothelial proliferations in effusion cytology. Cancer Cytopathol 2020; 128:939-947. [PMID: 32678499 DOI: 10.1002/cncy.22326] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND A number of ancillary tests have been developed that aid in the diagnosis of mesothelioma in cytology specimens. The aim of this retrospective study was to determine whether testing for BAP1 and CDKN2A/p16 status in effusion specimens preceding the tissue diagnosis of mesothelioma would improve diagnostic accuracy and allow an earlier diagnosis of malignancy. METHODS The study cohort included 99 matched cytology fluid specimens from 74 patients with a surgical specimen diagnosis of malignant mesothelioma (67 epithelioid, 7 biphasic, 55 pleural, and 19 peritoneal). BAP1 immunohistochemistry and p16 fluorescence in situ hybridization (FISH) were performed retrospectively. RESULTS BAP1 or p16 FISH testing revealed a loss in 7 of 18 (39%) samples originally categorized as benign/reactive, 20 of 33 (61%) interpretable samples categorized as atypical, and 10 of 14 (71%) cases suspicious for mesothelioma. In some cases, the diagnosis of mesothelioma could have been made up to 9 months before biopsy. Similarly, loss of BAP1 or p16 was found in 28 of 30 (93%) samples categorized as malignant, with some cases diagnosable up to 6 months before biopsy. Overall, loss of BAP1 and/or CDKN2A/p16 homozygous deletion would change the diagnostic interpretation in 37 of 60 (62%) (P = .07) effusion specimens, particularly in pleural effusions (32 of 48 samples) (P = .002). The sensitivity of morphologic interpretation alone was 30.3%; however, adding testing for BAP1 and p16 resulted in an increase in sensitivity to 68.7%. (P < .0001). CONCLUSION These findings suggest that routine use of BAP1 immunochemistry and p16 FISH as adjunctive tests improves the diagnostic accuracy of cytology specimens and potentially allows an earlier diagnosis of malignant mesothelioma.
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Affiliation(s)
- Martin Chevrier
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sara E Monaco
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Jacob A Jerome
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | | | - Andrew Churg
- Department of Pathology, Vancouver General Hospital and University of British Columbia, Vancouver, British Columbia, Canada
| | - Sanja Dacic
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
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21
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Abstract
Malignant mesothelioma is an uncommon tumor that may be difficult to diagnose. The International Mesothelioma Interest Group has been writing guidelines for pathological diagnosis that are periodically updated. The guidelines are being updated based on published literature in the last 3 years, and experience of more than 20 leading international pathologists in the field who will be co-authors. Updates were discussed by attendees of the Pulmonary Pathology Society Biennial Meeting (Dubrovnik, Croatia, June 2019). Areas with significant advancements/changes include utilization of immunohistochemistry (establishing mesothelial lineage and benign versus malignant), prognosis and nuclear grading, biphasic malignant mesothelioma, transitional pattern, malignant mesothelioma in situ, and therapeutic/molecular targets.
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Affiliation(s)
- Jefree J Schulte
- Department of Pathology, The University of Chicago, Chicago, IL, USA
| | - Aliya N Husain
- Department of Pathology, The University of Chicago, Chicago, IL, USA
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22
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Churg A, Dacic S, Galateau-Salle F, Attanoos R, de Perrot M. Malignant Mesothelioma In Situ: Clinical and Pathologic Implications. J Thorac Oncol 2020; 15:899-901. [PMID: 32307274 DOI: 10.1016/j.jtho.2020.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/28/2020] [Accepted: 03/05/2020] [Indexed: 11/20/2022]
Affiliation(s)
- Andrew Churg
- Department of Pathology, Vancouver General Hospital and University of British Columbia, Vancouver, British Columbia, Canada.
| | - Sanja Dacic
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | | | - Richard Attanoos
- Department of Cellular Pathology, University Hospital of Wales, Cardiff, Wales, United Kingdom
| | - Marc de Perrot
- Division of Thoracic Surgery, University Health Network, University of Toronto, Toronto, Ontario, Canada
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