RESUMEN
The CLIPPERS syndrome is a chronic, inflammatory disorder of the central nervous system of unknown etiology, which was first described in 2010 by Pittock and colleagues. It is characterized by typical magnetic resonance imaging (MRI) changes with lesions mainly in the brainstem, a perivascular, lymphohistiocytic inflammatory process and significant improvement under glucocorticoid therapy. Here we describe the case of a 40-year-old male who presented initially with typical clinical and radiological signs of CLIPPERS syndrome and who achieved complete remission under immunosuppressive therapy. Two years later, he presented with severe headaches. The MRI showed a reappearance of the lesion in the cerebellum, but now with a confluent character. The first brain biopsy showed lymphoproliferation. A second brain biopsy could finally confirm the suspected diagnosis of a primary CNS lymphoma.