[A patient with dizziness and gait instability - a diagnostic challenge].

A 58-year-old patient presented with progressive cerebellar ataxia and lymphocytic pleocytosis with normal MRI findings. Detection of Anti-TR(DNER) antibodies led to the diagnosis of paraneoplastic encephalitis. Tumor workup revealed anaplastic large cell lymphoma. Combined immunotherapy and chemotherapy resulted in clinical stabilization.