Migration of cerebral sparganosis to the ipsilateral cerebellar hemisphere

We report the case of a 52-year-old man in whom multiple conglomerated ring-enhanced lesions in the left frontal lobe were revealed on magnetic resonance imaging (MRI); further, he presented with headache. Subtotal resection of the mass was performed and the histopathological diagnosis of gemistocytic astrocytoma was made. He received postoperative radiotherapy of remnant mass. Six months post-surgery, new multiple lesions were developed on the left cerebellum and the lesion yielded radiological findings that were quite similar to those of the lesion previously observed in the left frontal lobe. Total resection was performed with the aid of neuronavigation and a live yellow 10-cm-long worm with an active scolex was found. A pathologist identified the worm as a sparganum of Spirometra mansoni. This suggests that the live worm may have moved to the ipsilateral cerebellum due to the stimulus from the surgery and radiation on the frontal lobe. Although this case presented characteristic MRI findings of sparganosis, we did not conduct a serological test; therefore, we misdiagnosed sparganosis as gemistocytic astrocytoma. To the best of our knowledge, this is the first report of the ipsilateral transtentorial migration of cerebral sparganosis.