Follow up of the Guidelines for Cytopathologic Diagnosis of Malignant Mesothelioma

Transcription

1 Follow up of the Guidelines for Cytopathologic Diagnosis of Malignant Mesothelioma Assoc. Prof. Katalin Dobra, Senior Lecturer in Molecular Pathology Karolinska University Hospital Stockholm, Sweden

2 Disclosure Information 29 th European Congress of Pathology Assoc. Prof. Katalin Dobra I have no relevant financial relationships to disclose.

3 International Guidelines. Guidelines for cytopathologic diagnosis of epithelioid and mixed type malignant mesothelioma. Complementary statement from the International Mesothelioma Interest Group, also endorsed by the International Academy of Cytology and the Papanicolaou Society of Cytopathology. Hjerpe A, Ascoli V, Bedrossian C, Boon M, Creaney J, Davidson B, Dejmek A, Dobra K, Fassina A, Field A, Firat P, Kamei T, Kobayashi T, Michael CW, Önder S, Segal A, Vielh P Published in Acta Cytol. 2015;59(1):2-16. Diagn Cytopathol Jul;43(7): Cytopathology Jun;26(3): CytoJournal, 2015, in press Comment in Cancer Cytopathol August;123: Ultimate goal to have the document merged with the histopathologic guidelines

4 Mesothelioma in effusions Recurrent haemorrhagic effusions often represent the first available biological material for malignant mesothelioma Previous histopathological guidelines claim need for histology Development of ancillary analyses now makes a specific diagnosis possible based on effusion cytology The guidelines describes how this can be achieved

5 EARLY DIAGNOSIS IS A CHALLENGE - Symptoms and morphological diagnosis are late - Negative effect on treatment outcome - Recurrent inflammatory or haemorrhagic effusions can obscure early stage malignant mesothelioma - For an early diagnosis awareness is needed - You must consider the possibility of mesothelioma Diagnosis

6 Basic requirements for the diagnosis 1. Identification of cells as malignant 2. To determine that these cells are of mesothelial origin 3. Specificity is the crucial measure The most important measure is the 100% positive predictive value

7 High cellularity Large number of cell groups (spheres or morula)

8 Cytological features of a Malignant Mesothelioma

9 Extracellular matrix cores Cellgroups with windows

10 1. To identify malignancy DDx: Reactive mesothelial hyperplasia ( mesotheliosis ) Can be difficult, often blend morphology in MM (minute atypia) Overlapping features between these two entities Have MM in mind when the sample is highly cellular If uncertain use ancillary techniques: Immunocytochemistry (Desmin, EMA, BAP-1 etc) Ploidy analysis (FISH) Electron microscopy Liberal use of Immunocytochemistry and FISH

11 Cellular criteria for malignancy Common cytological criteria Hyperchromasia Polymorphism Atypical nucleoli Etc. Warning! Reactive changes can be extensive

12 Morphology of the MM cell Macronucleoli Cell-within-cell Multinucleated cells The diagnosis must be verified with ancillary analyses!

13 Two helpful double stainings BerEp4/Calretinin Desmin /EMA Adenocarcinoma Malignant Mesothelioma Reactive mesothelium ( Mesotheliosis )

14 THE MOLECULAR LANDSAPE OF MALIGNAT MESOTHELIOMA Tumor suppressor genes are frequently altered: Deletion of CDKN2A (p16; 9p21.3) (50% -100%) (Bott et al. 2011, Takeda et al. 2012, Matsumoto et al. 2013, Cosmic databasen) BAP-1 mutation (20-81%) related to uveal melanoma (Bott et al. 2011, Yoshikawa et al ) Neurofibromatosis 2 (NF2)(20% -60%) (Takeda et al. 2012, Thurneysen et al. 2009, Bott et al. 2011) P53-mutation (20%) late event No recurrent oncogene mutation have yet been identified in MPM.

15 Bott. et al. Nature Genetics 2011, Testa JR Nature Genetics 2011

16 FISH in benign and malignant cells Chromosome # 3 Chromosome #7 Chromosome #17 9p21

17 Electron Microscopy to establish malignancy Neolumina indicates malignancy

18 BAP- 1: Concordance between histology and cytology H&E BAP-1 clone C-4 67% p16 FISH 80% Hwang H.C et al. 2016

19 2. The mesothelial lineage DDx: Adenocarcinoma It is strongly recommended that the mesothelial phenotype always is verified with ancillary analyses (Immunocytochemistry, Electron microscopy, soluble biomarkers). The diagnosis should not be based on Pap/MGG stained slides only

20 ICC and mesothelial lineage No single antibody is specific enough to be used as the sole criteria for mesothelial lineage Antibody panels are needed Antibody panels mentioned in the paper Pro MM: Calretinin, Mesothelin, D2-40, WT-1, CK5/6, etc Contra MM: CEA, BerEp4, MOC31, TTF-1, CD15, Sialyl-TN, B72.3 How many antibodies to use? Minimum 2 immunomarkers in favour and 2 excluding the possibility of mesothelioma If inconclusive reaction pattern add additional markers

21 The same epitopes as for Immunohistochemistry Works with cell blocks and cytospin Figure Claire W Michael

22 Cell block versus cytospin preparation

23 MALIGNANT MESOTHELIOMA- IMMUNOSTAINING MGG BerEp4 (brown)/ Calretinin (red) EMA Mesothelin

24 PLEURAL EFFUSION: adenocarcinoma dual staining MGG BerEp4 (brown)/calretinin (red)

25 CLINICAL DECISION: TTF-1 positive Lung adenocarcinoma metastasis CK 7 TTF-1(brown) / Napsin A (red) Negative EGFR mutation staus FISH ALK-1 break apart probe

26 Peritoneal and pericardial MM Other spectrum of differential diagnoses than in the pleura Ovarian carcinomas, use ICC Colorectal cancer Pericardial MM Care not to over diagnose reactive proliferation, use ancillary techniques

27 Laboratory resources needed ICC is essential for a correct diagnosis Allows also the less resourced laboratory to make a specific diagnosis in most cases. The optional analyses (EM and biomarkers) will add sensitivity

28 Optional ancillary analyses Electron microscopy Soluble biomarkers Hyaluronan Mesothelin

29 Electron microscopy Gold Standard Well known criteria Can be performed on cell groups from effusions Early fixation in glutaraldehyde is mandatory

30 Optional analyses, biomarkers Principally no difference between cell- bound and secreted biomarkers Hyaluronan and Mesothelin Analysed by Elisa (nowadays) Hyaluronan has high specificity with patognomonic value in >50% of cases Mesothelin is produced also by some other tumours Analysing both and applying a logistic interpretation model improves sensitivity

31 DIAGNOSTIC USE OF BIOMARKER BATTERIES

32 The indication for a biopsy remains when: Cytology fails to reach a conclusive diagnosis In cases where information on a possible sarcomatoid component is necessary for decision making and subsequent treatment

33 Why should we bother.. Received chemotherapy Not eligible for chemotherapy

34 Concluding remarks The guidelines requests at least 4 ICC reactions (2 in favour of and 2 against). If no conclusive diagnosis can be reached add further antibodies or use ancillary methods Then PPV can be maintained on 100% Treatment can be initiated without delay based on cytological diagnosis Longitudinal follow up shows 6-9 month delay (median 1 month) if invasion in fatty tissue and histology is strictly requested Cytology will significantly improve patient survival Sarcomatoid mesotheliomas are not detected as they are not exfoliating

35 Thank you! Prof. em. Anders Hjerpe Sulaf Abd Own Filip Mundt Ghazal Heidari-Hamedani -Cytology Laboratory -Immunocytochemistry/ -FISH working group - Molecular Biology Team Cancerfonden AFA