Paraneoplastic Cerebellar Degeneration Associated with Anti-Yo Antibodies Appearing as a Leptomeningeal Cerebellar Carcinomatosis at MRI: a Case Report

Anti Yo antibodies (AYA) are the antibodies most frequently identified with Paraneoplastic Cerebellar Degeneration (PCD). They are detected above all in PCD associated with breast and gynecologic malignancies. Here, we report a third case of PCD with cerebellar contrast enhancement findings at MRI. In fact, AYA cross anti cerebellar cortex immune reaction leads mainly to hyperintensity signals in T2-weighted-MRI sequences, followed by cerebellar atrophy. As such, meningeal contrast enhancement could lead to a diagnostic pitfall as it can be considered a carcinomatosis - above all in serum antibody negative cases as well as when a metastatic tumour is found. Our patient had no tumoral cells in the cerebrospinal fluid and her neurological syndrome remained stable after immunoglobulin treatment. AYA serum finding was diriment for PCD diagnosis.