LAUSR

Background Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an increasingly recognized neuroinflammatory syndrome that predominantly affects the pontine and cerebellar brain structures. Characteristically, patients will develop glucocorticoid-responsive brainstem disorders, demonstrate pontocerebellar contrast enhancement on magnetic resonance imaging (MRI), and exhibit an angiocentric, lymphocytic infiltrate in brain biopsies. We have presented and discussed 2 novel and challenging cases of CLIPPERS syndrome to highlight the clinical and radiological diversity of the syndrome. Case Description The first case was of a 66-year-old male patient who had presented with dizziness, headaches, gait disturbances, mild cognitive impairment, and visual field loss to the left side. MRI revealed 1 cerebellar and 2 occipital contrast-enhancing lesions that were suspicious for intracerebral metastases. The second case was of a 53-year-old male patient who had presented with temporal lobe epilepsy, anomic aphasia, and mild cognitive impairment. MRI demonstrated 4 contrast-enhancing lesions in the pons, temporal lobe, and thalamus that were suspicious for intracerebral lymphoma. Because of the radiological presentation, neoplastic disease was the most plausible diagnosis for both patients. However, repeated biopsies ruled out tumor manifestation, and the findings were finally consistent with CLIPPERS syndrome. The significant and long-lasting response to immunosuppressive treatment confirmed the diagnosis. Conclusions In both cases, the characteristics of CLIPPERS syndrome imitated malignant tumor growth. This scenario can be challenging to clinicians and necessitates inclusion of this neuroinflammatory syndrome in the differential diagnosis of neuro-oncological disease.