Paraneoplastic Cerebellar Degeneration Associated With anti-Yo Antibodies Appearing as a Leptomeningeal Cerebellar Carcinomatosis at Mri. A Case Report.

Anti-Yo antibodies are the antibodies most frequently identified with paraneoplastic cerebellar degeneration (PCD). They are detected above all in PCD associated with breast and gynaecologic 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 tumoural cells in the cerebrospinal fluid and her neurological syndrome remained stable after immunoglobulin treatment. Anti-Yo antibody serum finding was diriment for PCD diagnosis.