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K. Geisinger



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    MO26 - Anatomical Pathology II (ID 129)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Pathology
    • Presentations: 1
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      MO26.10 - DISCUSSANT (ID 3990)

      11:20 - 11:30  |  Author(s): K. Geisinger

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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    MS21 - Practical Problems in Lung Cancer Diagnosis - Application of the 2011 Adenocarcinoma Classification (ID 38)

    • Event: WCLC 2013
    • Type: Mini Symposia
    • Track: Pathology
    • Presentations: 1
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      MS21.1 - Cytological Diagnosis (ID 556)

      14:05 - 14:22  |  Author(s): K. Geisinger

      • Abstract
      • Presentation
      • Slides

      Abstract
      Whenever a major alteration in histopathologic classification occurs, important ramifications for cytopathology follow. Furthermore, the recent recognition that associations of specific types of epithelial malignancies of the lung are associated with different prognoses and therapeutic complications also directly impacts diagnostic cytology. One important question is: how well can we distinguish adenocarcinoma, squamous cell carcinoma, and other nonsmall cell carcinomas (NSCLC) from each other in cytologic preparations? The answer is very well, with most recent data emanating from aspiration samples. Based purely on routine cytomorphology, approximately 90% of all specimens with NSCLC can be rendered by strict adherence to classic well indoctrinated cellular features. When the distinction cannot be rendered by morphology alone, the addtion of a small battery of immunochemical reactions raises the proportion of correct cell typing to nearlly 100%. Recommendations emphasize using a limited array of antibodies, eg. targets such as TTF-1, cytokeratin 5/6, and synaptophysin. In the infrequent case in which this does not make clear the cell type, a diagnosis of NSCLC, NOS is preferred over large cell carcinoma. Once a tumor is interpreted as adenocarcinoma, how well do we do in determining the predominant histologic subtype from the 2011 classification? The answer is poorly. This is related to both the small sample size with the recognition of the histologic heterogeneity within a sizeable tumor mass and the concept that the rather uniform manners in which neoplastic cells aggregate and present themselves in aspiration and exfoliative smears is typical of all types of adenocarcinomas and thus not representative of the histologic subtype. Current data supports the general notion that the predominant histologic subtype correlates with prognosis, and thus may serve as a morphologic grading surrogate. As just stated, it does not appear that cytology will permit such a parallel assessment. However, there is some evidence that certain nuclear attributes of adenocarcinoma cells in cytologic specimens are associated with prognosis and, hence, nuclear grading may be of value in this regard. Features which include nuclear contour, chromatin pattern, and the prominence of nucleoli can be used to formulate a meaningful nuclear grading system. This is likely better performed with alcohol-fixed Papanicolaou stained specimnes compared to air-dried Romanowsky stained samples. Note that mitotic figure counting is not a component of this proposal. It is crucial to recognize that cytologic samples provide a substrate for the molecular testing of therapeutically important mutations in adenocarcinoma cells which seem to be equal to histologic specimens. Thus, it is very relevant that sufficient cytologic material be collected at the very time of sampling and that it be utlized in an extremely judicious manner.

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    P2.15 - Poster Session 2 - Thymoma (ID 191)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Thymoma & Other Thoracic Malignancies
    • Presentations: 1
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      P2.15-007 - Digital Microscopy Reproducibility Study of Thymic Epithelial Neoplasms (ID 2883)

      09:30 - 09:30  |  Author(s): K. Geisinger

      • Abstract

      Background
      Thymic epithelial tumors are rare and morphologically heterogeneous which constitutes interpretive challenges to practicing pathologists. Advances in digital imaging provide an opportunity to disseminate knowledge of these rare tumors, and can be potentially useful as diagnostic and educational tools. However the diagnostic reproducibility utilizing digital slide imaging needs to be validated.

      Methods
      Twenty cases of thymomas or thymic carcinomas with characteristic morphologic features were scanned into the APERIO system. The images were sent to pathologists with expertise in thoracic pathology in 6 different centers. The pathologists were asked to classify the tumors according to the World Health Organization (WHO) 2004 classification and to evaluate invasion on the scanned material. In addition, they were asked to indicate their confidence in the diagnosis using the imaging system. Interobserver agreement was evaluated. After discussions of the first 20 cases, a second round representing 10 cases were evaluated by digital images by the participating pathologists.

      Results
      In the initial phase, there was agreement among pathologists for the diagnosis of thymoma and thymic carcinoma in 75 % of cases (n= 14), in the remaining 6 cases, the disagreement was between cases of B3 thymoma and thymic carcinoma in five and between Type A thymoma and thymic carcinoma in one (kappa=0.43, moderate agreement). Perfect agreement was seen in 4 thymoma cases, where all pathologists diagnosed the same WHO type. These were classical cases with pushing borders and large fibrous bands. In other cases there were disagreements among the classification of the tumor as B2, B3, and AB. The cases with most disagreement were histologically heterogeneous with combined patterns. When invasion was evaluated, the overall k coefficient is 0.49 for the presence of invasion. In the second round of cases, we observed an improvement in interobserver agreement for diagnosis thymoma vs thymic carcinoma (kappa = 0.63) and for determination of invasion (present versus absent) (k=0.57). Most pathologists found that the digital images were comparable with glass slides and the overall confidence in the diagnosis was good.

      Conclusion
      The diagnostic accuracy of thymic epithelial tumors by digital images is equivalent to that reported in prior studies using glass slides. Digital imaging is a good tool for remote consultation and educational purposes. In the majority of specimens, pathologists are able to make the correct diagnosis. Major challenges include distinguishing B3 tumors and carcinomas and tumors with morphologic heterogeneity. The overall agreement can be improved after training. This technology could be used to establish a digital slide bank which could provide a method for training pathologists with less experience in the pathology of thymic epithelial tumors, to foster collaborative work in the field, and diagnostic consultation.