[Anti-Yo antibody associated paraneoplastic cerebellar degeneration with gastric adenocarcinoma in a male patient: a case report].

We report a 71-year-old man presenting with paraneoplastic cerebellar degeneration (PCD) associated anti-Yo antibody after surgery for gastric adenocarcinoma. Seven months after partial gastrectomy, he deviated to the right on walking. Furthermore, a feeling of dysarthria appeared and he was unable to sit after 2 months. When he was hospitalized, he showed a disturbance of his eye movement on lower gaze, a nystagmus on lateral gaze, saccadic eye movement on smooth pursuit, cerebellar ataxia, and decreasing of muscle tonus in his extremities. However, no atrophic findings of the brainstem and cerebellum were revealed by brain MRI. He responded poorly to treatment with high-dose methylprednisolone, high-dose immunoglobulin, double filtration plasmapheresis and rehabilitation. There was a strong anti-Yo immunohistochemical staining of the cytoplasm in both the patient's tumor cells and normal cerebellar Purkinje cells. These findings suggest that PCD associated with anti-Yo antibody triggered by adenocarcinoma might occur in this male patient.