[Subacute paraneoplastic cerebellar degeneration in microcytic carcinoma of the lung. Presentation of 2 cases].

Subacute paraneoplastic cerebellous degeneration is a rare syndrome which is found in less than 1% of patients with cancer. Small cell cancer of the lung and of the ovary are the two neoplasms most frequently associated to this entity. Two patients with small cell lung cancer who initially had a cerebellous syndrome in which no sign of macroscopic cerebellous lesion could be demonstrated by either computerized tomography or nuclear magnetic resonance of the head are presented. One of the patients was evaluated at autopsy. Both patients were treated with polychemotherapy with which partial response was obtained. Neurologic symptomatology was not alleviated in the first patient with death due to bronchopneumonia at 5.5 months of initiation of the disease, while improvement of the cerebellous paraneoplastic syndrome was achieved in the second patient. The different evolution of subacute paraneoplastic cerebellous degeneration in two patients in whom antibodies were not demonstrated and in whom initial response of the tumor to chemotherapy was achieved may be explained by the second patient having undergone prolonged treatment of 6 cycles suggesting a strict relation ship between the tumor and subacute cerebellous degeneration which, to date, remains unknown.