Is there a role for chemotherapy for asymptomatic Well-Differentiated Papillary Mesothelioma or Multicystic mesothelioma?  

No role for chemotherapy, in my opinion. These presentations should be handled by observation if asymptomatic, or surgery when symptoms start to appear. Treatment should be debulking with or without hyperthermic perfusion with local chemotherapy.There are many case reports of chemotherapy treatments...