We experienced a case of breast cancer in a 51-year-old woman who had been treated for spinocerebellar degeneration (SCD) at the Department of ENT of our hospital for about 12 years. The patient was admitted to the hospital because of a left breast tumor detected at a mass screening. On admission the tumor which was comparatively discrete, movable, and 3.0×2.4cm in size was palpabled in the A region of the left breast. Histological diagnosis indicated solid ductal adenocarcinoma. No other lesion was detected by preoperative examination. A modified radical mastectomy was performed (T2aN0M0, Stage II), There has been no sign of recurrence nor any progress of SCD, as of 23 months after the initial operation.
SCD is recognized as one of paraneoplastic disorders. It is characterized by the acute or subacute onset of progressive neuropathy of spino-cerebellar lesions. Whereas SCD has most frequently been reported as a complication of ovarian or lung cancer, its association with breast cancer has been uncommonly recognized, amounting to 64 cases in the world. We have suggested that surgical treatment of the primary malignancy may result in something of an improvement in the neurologic condition.