Trial of Selumetinib in Patients With Neurofibromatosis Type II Related Tumors

In this research study the researchers want to learn more about the effects (both good and bad) the study drug selumetinib has on participants with neurofibromatosis type II (NF2) related tumor. The researchers are asking patients with NF2 related tumors to be in the study, because their hearing has decreased and/or their NF2 related tumor has started to grow. The goals of this study are: * Determine if selumetinib will stop NF2 related tumors from growing * Measure the changes in hearing after receiving selumetinib for 6 months. * Determine if selumetinib improves how participants feel (physically and emotionally) and how participants can perform daily activities. * Examine tumor tissue, if available, in a laboratory to see if NF2 related tumors have targets of selumetinib.