(3) Biphasic (Mixed). Epithelioid comprises about 50-60% of malignant mesothelioma cases and generally holds a better prognosis than the Sarcomatoid or Biphasic subtypes. [22] Staging Staging of mesothelioma is based on the recommendation by the International Mesothelioma Interest Group. [23] TNM classification of the primary tumor, lymph node involvement, and distant