Background: The malignant transformation of vestibular schwannoma (VS) is a rare identity. We present a case of spontaneous transformation of VS and a short literature review. Case Presentation: A 41-year-old female had presented to us with vertigo, tinnitus, and hearing loss. She was diagnosed with left VS and underwent surgical resection. The initial histology was reported as benign grade 1 schwannoma. She subsequently presented to the hospital with hematoma in the tumor cavity after 4 and 5 months, respectively. Her repeat magnetic resonance imaging (MRI) showed growth of the residual tumor. She underwent a second translabyrinthine excision of the tumor. The histology from the second operation showed components of malignant transformation. One month postoperatively she suffered an acute decline in her conscious level. Repeat MRI demonstrated rapid regrowth of the tumor with further hemorrhage. In view of her rapid decline and perceived futility of further intervention and respecting her premorbid wishes, further escalation of therapy was deemed inappropriate. Conclusion: VS can transform into a malignant tumor even in the absence of radiation therapy. This may be considered in case of rapid regrowth of the tumor.

Keywords: Case report, vestibular schwannoma, malignant transformation, cerebellopontine angle tumor