[Subacute cerebellar degeneration with HCG-beta positive seminoma of the testis]

Neurological disorders associated with a malignant neoplasm, which is not caused by a direct effect such as metastasis, infiltration or compression, is called carcinomatous neuromyopathy. Subacute cerebellar degeneration recognized in this category is characterized by acutely or subacutely progressive cerebellar ataxia and widespread loss of Purkinje cells. There have been several reports of subacute cerebellar degeneration in lung carcinoma, ovarian carcinoma and Hodgkin's disease, but rare in urogenital malignancies. We present a patient with neurological disorder considered subacute cerebellar degeneration associated with HCG-beta positive seminoma. A 29-year-old man noticed a left intrascrotal mass in the summer of 1984. The mass began to grow in April, 1985 and diplopia, gait disturbance and dysarthria appeared late in May. He consulted our hospital on July 20, 1985. Serum human chorionic gonadotropin (HCG)-beta was elevated to 200 ng/ml but alpha-fetoprotein and carcinoembryonic antigen were normal. Left high orchiectomy was performed and the tumor was diagnosed histologically as typical seminoma. Bulky metastatic tumor was recognized in retroperitoneum on abdominal CT but brain CT was normal. VAB VI chemotherapy was performed. The retroperitoneal metastatic tumor disappeared and HCG-beta was normalized and complete remission achieved, but cerebellar symptoms still remain 14 months after remission. This case is considered to be subacute cerebellar degeneration associated with seminoma and is the second case with testicular carcinoma reported.