Vestibular schwannoma: an unusual post radiotherapy response

Vestibular schwannoma is a relatively uncommon tumor. Although, it is benign but locally expansile and spreads to damage the adjacent structures. Treatment strategy includes surgery, Stereotactic Radiosurgery (SRS) either by standard or hypofractionated protocols. Due to its benign nature, radiation therapy cannot remove the tumor completely, instead radiation therapy halts the growth of vestibular schwannoma and inactivates this benign tumor. Response of radiation in the form of tumor shrinkage is seen 2 - 2.5 years after the radiations. We report a case of vestibular Schwannoma in which residual tumor of 3.1 cm size following subtotal resection was irradiated of the dose of 54 Gy in 30 equal fractions on 3-Dimensional Conformal Radiation Therapy (3-DCRT). A follow-up CT scan brain after 2 months of radiotherapy showed complete disappearance of the disease categorized as complete response. This is an unusual phenomenon and is likely due to the very rarely seen malignant transformation or presence of malignant component in this benign tumor.