Paraneoplastic cerebellar degeneration associated with cerebellar hypermetabolism: Case report

RATIONALE: Paraneoplastic cerebellar degeneration (PCD) is an immune-mediated neurological deficit affecting the cerebellum. Anti-Yo antibody positive PCD is a rare occurrence most likely associated with gynecologic or breast malignancies. The identification of the underlying tumor is a diagnostic challenge in many of these patients. PATIENT CONCERNS: We present a 68-year-old woman with acute symptoms of PCD as a first sign of underlying occult malignancy. Further investigation revealed a positive anti-Yo antibody. Although brain magnetic resonance imaging (MRI) was unremarkable, positron emission tomography (PET)/computed tomography (CT) revealed intense hypermetabolism of cerebellum and diffused hypometabolism in the rest of brain. On 1-year follow-up, despite the primary malignancy is still unknown, her symptoms improved significantly after immunotherapy. DIAGNOSES: Paraneoplastic cerebellar degeneration. INTERVENTIONS: The patient was given IV methylprednisolone 500 mg once a day for 5 consecutive days, followed by oral prednisone 60 mg once a day for 3 months. OUTCOMES: The patient's symptoms were gradually improved during the hospitalization period. On one year follow up, she was able to walk independently and perform some simple tasks. LESSONS: Cerebellar hypermetabolism in PCD suspected patients may help confirming the diagnosis in an earlier stage and may predict a better outcome after immunotherapy.