Acoustic Neuroma: Possibly Malignant?
Recently, Maducdoc et al (2015) reported on 12 cases of “malignant transformation” from benign to malignant acoustic neuromas. Of note, some 42 percent of neurotologists treat acoustic neuroma with stereotactic radio surgery (SRS). Indeed, 8 of the 12 cases were noted following SRS and microsurgery (MS), while 4 of the 12 transformed after MS only. The authors note that the mechanism that may lead to a malignant transformation seems “more obvious” for SRS, and is less well understood for MS. The authors note they also found 18 cases of “primary malignant” or transformation to malignant without any intervention.
Maducdoc et al note that given the very low occurrence of malignant acoustic neuromas, it is possible these are simply rare, spontaneous events that cannot be ruled out. They conclude that “…it remains possible that the association of malignant transformation…after SRS or MS represents the natural history of rare unfortunate patients experiencing this event….”
For More Information, References, and Recommendations
Maducdoc MM, Ghavami Y, Linskey ME, Djalilian HR. (2015) Evaluation of Reported Malignant Transformation of Vestibular Schwannoma – De Novo and After Stereotactic Radiosurgery or Surgery. Otology & Neurotology 36:1301-1308.