Sarcomatoid differentiation during progression of malignant pleural mesothelioma

Background: Malignant pleural mesothelioma (MPM) is an aggressive tumor with a high local recurrence rate despite multimodal treatment. We evaluated the prognostic impact of morphological and immunohistochemical changes in sequential biopsies obtained during disease progression. Methods: Tissue microarrays were constructed from samples of 36 MPM patients taken before induction-chemotherapy, during surgery and at tumor recurrence. Immunohistochemical staining and scoring for calretinin, cytokeratin 5/6 (CK5/6) and Wilm's tumor-1 (WT-1), mesothelin, osteopontin, and fibulin-3 was performed. Results were correlated…