CH★★★★★5.0(1)Dr. Charles Hollen, MDHematology / Oncology SpecialistOklahoma City, OK34 Years of ExperienceAccepting patientsAffiliated with a Castle Connolly Top Hospital34 Years of ExperienceAccepting patientsAffiliated with a Castle Connolly Top HospitalRatings & ReviewsMost RecentHighest Rated08/24/2011Ms Joan LongDr. Hollen is a wonderful doctor. He diagnosis my problem before anyone else could figure it out. He spends more time with me than any doctor I have ever had. He gets down on my level and really listens. I would recommend him to anyone.1