Recent advances in lung tumors and tumor like lesions


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Recent advances in lung tumors and tumor like lesions

  2. 2. WHO CLASSIFICATION SQUAMOUS CELL CARCINOMA The central type and the peripheral type According to a study the patient population of the peripheral type was older, improved survival, lower lymphatic vessel involvement, and lymph node metastasis IHC : Low and High Molecular weight keratins ( CK 5/6) P63, p40 Involucrin
  3. 3. Require evidence of either keratinization or intercellular bridging Well , moderately or poorly differentiated carcinoma
  4. 4. 1) Small cell variant - vs small cell carcinoma ( lack the nuclear characteristics of small cell ca and may show focal keratinization ) 2) Clear cell variant 3) Papillary variant 4) Basaloid – Very aggressive clinical course , peripheral palisading of cells
  7. 7. SMALL CELL CARCINOMA Strongly a/w smoking Variants- 1. Small cell (pure) 2. Combined small cell/ non small cell IHC- Chromogranin A ( specific ) synaptophysin ( sensitive) NSE N CAM (CD 56) bombesin
  8. 8. Microscopy Diffuse growth of small tumor cells Hyperchromatic finely granular nuclei Inconspicuous nucleoli Thin nuclear membrane Scant , faintly stained finely granular cytoplasm Ill defined cell borders Nuclear moulding Stroma is delicate , finely vascular Frequent mitotic figures and individual cell necrosis
  9. 9. Necrosis leading to diffusion of chromatin to wall of the blood vessels which appear hematoxyphillic +ve for feulgen reaction Also seen in lymphomas, seminomas AZZOPARDI EFFECT
  10. 10. Adenocarcinoma Adenocarcinoma, mixed subtype Acinar adenocarcinoma Papillary adenocarcinoma Bronchioloalveolar carcinoma Nonmucinous Mucinous Mixed nonmucinous and mucinous or indeterminate Solid adenocarcinoma with mucin production Fetal adenocarcinoma Mucinous (“colloid”) carcinoma Mucinous cystadenocarcinoma Signet ring adenocarcinoma Clear cell adenocarcinoma
  11. 11. MUCINOUS NON MUCINOUS Neoplastic cells grow exclusively along lining of alveolar walls without any evidence of infiltration into interstitium – LEPIDIC pattern BRONCHOALVEOLAR CARCINOMA
  12. 12. CLEAR CELL ADENOCARCINOMA Mucinous (“colloid”) carcinoma
  13. 13. Large cell neuroendocrine carcinoma Combined large cell neuroendocrine carcinoma Basaloid carcinoma Lymphoepithelioma-like carcinoma Clear cell carcinoma Large cell carcinoma with rhabdoid phenotype LARGE CELL CARCINOMA
  14. 14. LARGE CELL NEUROENDOCRINE CARCINOMA Organoid , nesting, trabecular growth, rosettes and perilobular palisading patterns Cells are generally large Moderate to abundant cytoplasm Nucleoli prominent Mitosis >11/10 HPF Positive NE markers – synaptophysin, chromogranin,CD56
  15. 15. LYMPHOEPITHELIOMA-LIKE CARCINOMA Tumor cell islands surrounded by prominent lymphoplasmacytic host response May be associated with Epstein-Barr virus
  16. 16. CARCINOID Typical and atypical carcinoids Uniform polygonal cells Inconspicous nucleoli Scant to moderate cytoplasm Necrosis and mitosis 2-10/10 HPF
  17. 17. TUMOR LIKE LESIONS Minute meningothelial nodules Nodular lymphoid hyperplasia Localized organizing pneumonia Nodular amyloid Hyalinizing granuloma Micronodular pneumocyte hyperplasia Endometriosis Rounded atelectasis Inflammatory pseudotumor Bronchial inflammatory polyp Congenital lesions
  18. 18. Minute Meningothelial Nodules Epithelial membrane antigen and vimentin - positive Cytokeratin, actin, and neuroendocrine markers - negative
  19. 19. Solid with irregular borders caused by widening of adjacent alveolar walls.
  20. 20. Whorls of cells are typical
  21. 21. Numerous secondary lymphoid follicles and fibrosis Nodular Lymphoid Hyperplasia
  22. 22. Secondary lymphoid follicles surrounded by lymphocytes and plasma cells
  23. 23. Numerous plasma cells associated with russel bodies (but absence of dutcher bodies)
  24. 24. FOCAL ORGANIZING PNEUMONIA Nonencapsulated nodule Fibroblastic intraalveolar proliferations that fill alveolar spaces, alveolar ducts, and respiratory bronchioles
  25. 25. This airway contains an accumulation of fibroblastic cells and inflammatory cells that extends into the adjacent respiratory bronchiole
  26. 26. Apical cap Irregular apical nodule (upper lobe > lower lobe) Subpleural, triangular contours with broad pleural base Irregular borders – radiologically- spiculated Overlying pleura can be thickened, resembling hyalinized pleural plaque
  27. 27. At interface with normal lung the alveoli shows emphysematous changes Apical cap showing abundant elastic tissue and collagen and occasional fibroblast
  28. 28. NODULAR AMYLOIDOSIS Nodular amyloidosis can be 1. Organ isolated ( idiopathic or due to chronic inflammation) 2. Part of systemic disease (Sjogren syndrome, multiple myeloma, lymphoma, or light chain disease) Detected as a solitary lung nodule Primary amyloidosis type Serum and urine testing in these patients does not show a monoclonal protein in many cases
  29. 29. Nodular amyloid is densely eosinophilic, with scant cellularity and without the fibrillar appearance of collagen
  30. 30. Amorphous eosinophilic material with sparse lymphoplasmacytic infiltrate
  31. 31. Multinucleated giant cells can be present
  32. 32. Ossification is often present in pulmonary amyloid
  33. 33. PULMONARY HYALINIZING GRANULOMA Idiopathic condition SFTs can also have areas of dense collagen but PHG is less cellular Also, cells of SFT are CD34 positive
  34. 34. A circumscribed nodule, centrally acellular with a rim of inflammatory cells, is typical of pulmonary hyalinizing granuloma
  35. 35. The central eosinophilic zone is composed of dense ropy collagen with scant spindled cells and no histocytic inflammation or necrosis
  36. 36. Peripheral subpleural area of lung tissue that becomes folded into an area of visceral pleural fibrosis Asbestos exposure causing parietal pleural plaques followed by visceral pleural adhesion is the typical scenario and then adjacent lung gets entrapped in pleural adhesions At the time of surgery the lysis of adhesions and reexpansion of the folded lung causes the nodule to disappear ROUNDED ATELECTASIS
  37. 37. markedly thickened and fibrotic pleura, with parietal pleural adhesion and encircled lung tissue
  38. 38. Underlying lung tissue is collapsed, adjacent to pleural fibrosis
  40. 40. IASLC/ATS/ERS Classification of Lung Adenocarcinoma in Resection Specimens Preinvasive lesions Atypical adenomatous hyperplasia Adenocarcinoma in situ (3 cm formerly BAC) Nonmucinous Mucinous Mixed mucinous/nonmucinous Minimally invasive adenocarcinoma (3 cm lepidic predominant tumor with 0.5cm invasion) Nonmucinous Mucinous Mixed mucinous/nonmucinous
  41. 41. Invasive adenocarcinoma Lepidic predominant (formerly nonmucinous BAC pattern, with 5 mm invasion) Acinar predominant Papillary predominant Micropapillary predominant Solid predominant with mucin production Variants of invasive adenocarcinoma Invasive mucinous adenocarcinoma (formerly mucinous BAC) Colloid Fetal (low and high grade) Enteric
  42. 42. RECOMMENDATION 1 Discontinuing use of the term BRONCHOALVEOLAR CARCINOMA(BAC)
  43. 43. RECOMMENDATION 2 ADENOCARCINOMA IN-SITU – for small ( ≤3cm) , solitary adenocarcinoma with pure lepidic growth Has 100% disease specific survival
  44. 44. Mucinous adenocarcinoma in situ
  45. 45. Nonmucinous adenocarcinoma in situ
  46. 46. RECOMMENDATION 3 MINIMALLY INVASIVE ADENOCARCINOMA (MIA)- for small (≤3cm) , solitary adenocarcinoma with predominant lepidic growth and small foci of invasion measuring (≤0.5cm) Near 100% disease specific survival The invasive component is defined as – 1. histological subtype other than a lepidic pattern (acinar, papillary, micropappilary, solid) 2. Tumor cells infiltrating myofibroblastic stroma MIA is excluded if – 1. invades blood vessels, lymphatics or pleura 2. Contains tumour necrosis
  47. 47. Size of the largest invasive area should be measured in the largest dimension Size of invasion is not summation of all such foci, if more than one occurs
  48. 48. RECOMMENDATION 4 INVASIVE ADENOCARCINOMA – most tumors consist of mixture of subtypes Individual tumors are classified according to predominant pattern and percentage of subtypes
  49. 49. RECOMMENDATION 5 In patients with multiple lung adenocarcinoma - determine whether tumors are metastasis or separate synchronous or metachronous primaries
  50. 50. RECOMMENDATION 6 LEPIDIC PREDOMINANT ADENOCARCINOMA (LPA) - replaces use of term “mixed subtype” Invasive adenocarcinoma is present in atleast one focus measuring more than 0.5cm in greatest dimension Invasion is defined as- 1. histological subtype other than lepidic pattern (acinar , papillary , micropapillary, solid) 2. Tumor cells invading myofibroblastic stroma Diagnosis of LPA is made if – 1. tumor invades lymphatics, blood vessels and pleura 2. contains tumor necrosis
  51. 51. RECOMMENDATION 7 Addition of one more subtype of invasive adenocarcinoma – micropapillary type Others are – solid, papillary, acinar, lepidic Micropapillary type- tumor cells grow in papillary tufts lacking fibrovascular core Associated with poor prognosis
  52. 52. RECOMMENDATION 8 NSCLC- NOS to be used as little as possible Recommended to further classify into more specific type such as adenocarcinoma or squamous cell carcinoma because- 1. adenocarcinoma respond to pemetrexed therapy better than squamous cell carcinoma 2. Potential life threatening hemorrhage can occur if patients with squamous cell carcinoma receive bevacizumab 3. EGFR and ALK mutation in adenocarcinoma respond to TKIs
  53. 53. Other recommendations are- Small cell variant of squamous cell carcinoma is removed in the new classification Other variants are papillary, clear cell and basaloid
  54. 54. Classification of Lung Cancer into Molecular Subtypes
  55. 55. EGFR gene encodes a transmembrane receptor binds to epidermal growth factor becomes activated EGFR tyrosine kinase activity stimulates activation of downstream pathways leading to DNA synthesis and cell proliferation Found in approx 15% of NSCLC SUBTYPE 1 - aberrations in the EGFR gene/pathway
  56. 56. 1. CHARACTERIZED BY MUTATIONS IN THE EGFR GENE Includes three classes of mutations – a. Class I - exon 19 in-frame deletions- most common b. Class II - single amino acid changes c. Class III - exon 20 in-frame duplication/insertions Treatment – 1st generation EGFR inhibitors – erlotinib and gefitinib
  57. 57. 2. Harbours a T790M mutation in exon 20 of the EGFR gene Mutations emerge in response to treatment with EGFR TKIs (erlotinib or gefitinib ) EGFR TKI compete with ATP for ATP binding site on the EGFR prevents autophosphorylation and activation of EGFR’s kinase domain T790M mutation increases EGFR’s affinity for ATP reduces potency of competitive tyrosine kinase inhibitors confers drug resistance 2nd gen EGFR inh - afatinib
  58. 58. SUBTYPE 2 - mutations in the K-ras gene Ras has many isoforms- 1. H-Ras mutation – in bladder cancer 2. N-Ras mutation – in melanomas 3. K-Ras mutation – in adenocarcinoma of lung, colon, pancreas Point mutations at codons 12, 13, or 60 in the K-ras oncogene lead to activation of K-ras protein Reported in 15% to 20% of all patients with NSCLC
  59. 59. Mutations at codon 12 most commonly detected K-ras mutations are seen almost exclusively in smokers K-ras mutations in NSCLC are associated with decreased response to EGFR TKIs.
  60. 60. SUBTYPE 3 - ALK REARRANGEMENTS It harbors the EML4-ALK fusion oncogene, a fusion between echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) The fusion generates a transforming tyrosine kinase, with as many as nine different variants identified Patients with EML4-ALK mutant tumors are characteristically younger, female, and never to light smokers ALK fusions have also been described in anaplastic lymphomas and in about 50% of inflammatory myofibroblastic tumors (IMTs) Treatment – ALK inh - crizotinib
  61. 61. SUBTYPE 4 - ABERRATIONS IN C-MET Characterized by either dysregulation or mutation of mesenchymal-epithelial transition factor receptor tyrosine kinase (c-MET)
  63. 63. Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors Guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology
  64. 64. Almost all EGFR and ALK abberations are seen in adenocarcinoma or NSCLC with adenocarcinoma component EGFR mutation seen in 15% of NSCLCs ALK rearrangements seen in 4% of adenocarcinomas Seen in younger age, females, non-smokers Rare EGFR mutation seen in pulmonary salivary gland-type tumors, large cell carcinoma, sarcomatoid carcionoma
  65. 65. INDICATIONS – 1. Adenocarcinoma or adenocarcinoma component 2. In tissues with incomplete sampling (biopsies,cytology) in which adenocarcinoma cant be excluded 3. In undifferentiated or large cell carcinoma – testing done if IHC positive for adenocarcinoma lineage(TTF- 1) or IHC negative for squamous cell carcionma lineage(P63 or P40) Not recommended in pure squamous cell carcinoma or pure small cell carcinoma
  66. 66. WHEN TO TEST EGFR mutation and ALK rearrangement testing ordered at time of diagnosis for patients presenting with advanced- stage disease (stage IV) or at time of recurrence or progression in patients who originally presented with lower-stage disease but were not previously tested
  67. 67. HOW RAPIDLY TEST RESULT BE AVAILABLE Within 1 week(5 working days) to a maximum of 2 week (10 working days)
  68. 68. PROCESSING OF SPECIMEN FOR EGFR MUTATION TESTING Formalin-fixed, paraffin-embedded (FFPE) specimens or fresh, frozen, or alcohol-fixed specimens for polymerase chain reaction (PCR)–based EGFR mutation tests Other tissue treatments (eg, acidic or heavy metal fixatives, or decalcifying solutions) should be avoided in specimens destined for EGFR testing Cytologic samples are also suitable for EGFR and ALK testing, with cell blocks being preferred over smear preparations.
  69. 69. SPECIMEN REQUIREMENTS FOR EGFR TESTING EGFR mutation testing can be performed on specimens procured by almost any procedure: surgical resection, open biopsy, endoscopy, transthoracic needle biopsy, fine- needle aspiration, or thoracentesis
  70. 70. HOW EGFR TESTING BE PERFORMED Should use EGFR test methods that are able to detect mutations in specimens with at least 50% cancer cell content Sanger sequencing with and without mutated allele enrichment is the recommended method EGFR copy number testing, by FISH or CISH, is less predictive than mutation testing and should not be used as a method for EGFR TKI treatment selection
  71. 71. There are 3 main types of EGFR IHC: IHC for total EGFR, IHC for phosphorylated EGFR, and IHC for mutated forms of EGFR IHC for total EGFR is not an acceptable test for EGFR TKI treatment selection because it correlates poorly or not at all with presence of EGFR mutations IHC FOR EGFR
  72. 72. IHC FOR MUTATED FORMS- antibodies directed against the most common mutated forms of EGFR: the 15-bp/5- amino-acid deletion in exon 19 and the L858R point mutation in exon 21 Even if IHC negative - molecular testing is still needed So IHC is too insensitive For patients with low cellularity specimen which is inadequate for DNA analysis, IHC may be the best option available
  73. 73. Role of KRAS analysis in selecting patients for EGFR TKI  The most common (~30%) oncogene mutated in lung adenocarcinomas is KRAS.  EGFR and KRAS mutations are mutually exclusive Testing for KRAS mutations as a negative predictor of response to EGFR TKI has become part of molecular diagnostic algorithms for lung adenocarcinoma in many centers if sample is sufficient
  74. 74. ADDITIONAL TEST IN SECONDARY OR ACQUIRED RESISTANCE TO EGFR TKI Such tests should be able to detect the secondary EGFR T790M mutation in as few as 5% of cells Most common mechanism of AR involves the emergence of an additional EGFR tyrosine kinase domain mutation, T790M This mutation is seen in approximately 50% of tumors at the time of treatment failure
  75. 75. T790M is often not present in every tumor cell, so conventional Sanger sequencing, even with microdissection, is considered insufficient for this testing Sanger sequencing with a mutation enriching strategy such as peptide nucleic acid/locked nucleic acid clamps, or a more sensitive assay (eg, allele-specific PCR) that targets the T790M mutation to be used Other rare second-site mutations in the EGFR tyrosine kinase domain have been described in AR specimens, including L747S, D761Y, and T854A
  76. 76. METHODS USED FOR ALK TESTING ALK FISH assay is done using dual-labeled break-apart probes Most common ALK rearrangements involves a pericentric inversion on the short arm of chromosome 2, which creates a fusion gene encoding the aminoterminal portion of EML4 and the intracellular region of ALK
  77. 77. The NPM-ALK translocation seen in anaplastic large cell lymphoma - not reported in lung cancer A commercial assay is available that contains an orange and green labeled probes With this probe set, wild-type configuration appears as fused yellow signal ALK rearrangement is seen as distinct and separated orange and green signals In the USA, FDA has approved this commercial assay as a “companion diagnostic” to select patients to receive an FDA-approved ALK TKI
  78. 78. ALK IHC may be considered as a screening methodology to select specimens for ALK FISH testing If IHC is negative – not tested for ALK rearrangement by FISH Tumors positive for ALK IHC, either weakly or strongly, referred to FISH for confirmation of a rearrangement
  79. 79. Specimen requirements for ALK FISH are generally similar to those for EGFR mutation testing: Formalin fixation is acceptable, specimens should have enough cancer cells to analyze clearly, and DNA- damaging fixatives or acidic decalcifying agents should be avoided, as should specimens with abundant necrosis FISH – Not performed on alcohol fixed samples Ideally performed on recently cut sections
  80. 80. Proper interpretation of the FDA- approved commercial break-apart assay The most common positive result of a break-apart dual- labeled FISH assay in lung cancer will result in nuclei with 1 separate orange and 1 separate green signal that are separated by a gap larger than 2 signal diameters The native unaltered ALK region will remain as a yellow fusion signal but also commonly appears as 2 narrowly split orange and green signals.
  81. 81. A case was considered positive if ≥15% of 50 nuclei assessed in a tumor-rich portion of the section showed the classic split-signal pattern Secondary mutations in ALK is seen that confer acquired resistance to crizotinib Number of such cases are too small to recommend testing for these mutations Anticipated for such testing in near future as effective second line therapies become available
  82. 82. MUST ALL ADENOCARCINOMAS BE TESTED FOR BOTH EGFR AND ALK First algorithm - test for EGFR mutations first and proceed to ALK FISH if the EGFR results are wild type Second algorithm - initial sensitive and rapid EGFR mutation screening test by a method such as denaturing high- performance liquid chromatography, high-resolution melting analysis, or single-stranded conformational polymorphism. could detect a mutation but fail to characterize it completely (ie, fail to define the size of an exon 19 deletion or distinguish between L858R and L861Q point mutations)
  84. 84. Stepwise-testing algorithms, if used, should nonetheless be completed within 10 working days THIRD ALGORITHM- Test for KRAS mutation KRAS mutation occurs in 25-30% of lung adenocarcinoma and such tumors do not have EGFR or ALK abberations If positive- no other test to be done If negative – can go for either 1st or 2nd algorithm Should not be undertaken if KRAS testing will exhaust the sample and thereby preclude EGFR and ALK testing
  85. 85. HOW SHOULD EGFR AND ALK RESULTS BE REPORTED? The preclinical section of reports should include specimen’s morphologic characteristics: diagnosis and tumor content (percentage of total nuclei that are malignant) The results section of reports should include, prominently, the names of any clinically significant mutations identified In case of ALK testing - The results section should also include the number of cells analyzed, and the number and percentage of cells with each finding
  86. 86. IHC SCORING FOR ALK FUSION 3 criteria: 3-intense, granular cytoplasmic staining 2- moderate, smooth cytoplasmic staining 1-faint cytoplasmic staining in 10% of tumor cells 0- no Staining Positive control was from a known CD30-positive ALCL Negative control was a mouse immunoglobulin G1 serum substitution for the primary antibody (ALK).
  87. 87. Score 3 showing intense, granular cytoplasmic staining
  88. 88. score 2 showing moderate, smooth (without the apparent granularity seen in score 3) cytoplasmic staining
  89. 89. score 1 showing faint, barely discernable cytoplasmic staining
  90. 90. score 0 showing no staining
  92. 92. 1. International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society International Multidisciplinary Classification of Lung Adenocarcinoma 2. WHO classification of lung tumors 3. Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors Guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology 4. Benign Tumors and Tumorlike Conditions of the Lung Alain C. Borczuk, MD REFERENCES
  93. 93. THANK YOU