Late recurrence of primary cerebellar germinoma at unusual site after complete response to radiotherapy.

Background: The primary cerebellar germinoma is exceptional and difficult to diagnose preoperatively. Its recurrence at the middle cranial fossa after complete response to radiotherapy is unique and associated with a poor prognosis. This article aims to report the successful management of the late recurrence of primary cerebellar germinoma at an unusual site after 4 years of complete response to radiotherapy.

Case Description: A 22-year-old male was admitted to our hospital with complaints of severe headache and loss of balance. Brain magnetic resonance imaging (MRI) showed a triventricular hydrocephalus due to a 45x50mm cerebellar mass. Our preliminary diagnosis was medulloblastoma. First, we placed a ventriculoperitoneal shunt with the medium-pressure valve, and then we used midline suboccipital craniotomy to remove the tumor completely. The histopathology was germinoma. The patient received 24 Gy craniospinal irradiation (CSI) with a 16 Gy boost to the primary site and had an MRI follow-up every six months. After a 4-year follow-up, he complained of recurrent severe headaches. The brain MRI illustrated a 62 × 61 mm temporal mass. We extirpated this tumor, and histopathology again revealed germinoma. After that, the patient received induction radiotherapy. The 1-year postoperative MRI showed no tumor remnant. At the time of writing, the patient had no headache and no neurological deficits.

Conclusion: Regular follow-ups with routine neuroaxis MRI should be recommended to detect recurrence early for all patients with intracranial germinomas. Surgical resection, if possible, and subsequent CSI are the most effective salvage treatment for recurrent germinoma.