Thymic Carcinoma Associated with Cerebellar Degeneration

We present the case of a 57-year-old man with ataxia and clinical and radiological features of cerebellar degeneration. Computed tomography showed a mediastinal mass and the patient was diagnosed with thymic carcinoma. Paraneoplastic cerebellar degeneration is aninfrequent disorder and its association with thymic carcinoma very rare. LEARNING POINTS: Unexplained subacute neurological symptoms in an adult patient should beconsidered in the possibility of a paraneoplastic syndrome. In patients over 50 years of age, acute or subacute cerebellar degeneration is paraneoplastic in 50% of cases. Small-cell lung cancer is the most common cancer-causing paraneoplastic cerebellar degeneration (PCD). Despite this, mediastinal tumours such as thymus neoplasms should not be ruled out in the differential diagnosis. Antineuronal antibodies are not detected in 40% of patients with PCD, sothe exclusion of other aetiologies or the demonstration of cancer formsthe basis of the final diagnosis.