Sex Cord-Gonadal Stromal TumorsGranulosa Cell TumorGastrointestinal Stromal TumorsStromal CellsProto-Oncogene Proteins c-kitGastrointestinal NeoplasmsBenzamidesPiperazinesPyrimidinesReceptor, Platelet-Derived Growth Factor alphaSpinal CordSpinal Cord InjuriesTumor Markers, BiologicalImmunohistochemistryEndometrial Stromal TumorsMesenchymomaAntineoplastic AgentsSarcoma, Endometrial StromalNephroma, Mesoblastic