CLIPPERS mimicking multifocal brain metastases: a diagnostic challenge.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare inflammatory disorder of the central nervous system that can radiologically mimic neoplastic or other inflammatory diseases. We report a 62-year-old woman with an incidental cerebellar lacunar infarct who presented with progressive central vertigo, dysarthria, and gait ataxia causing near falls. Neurological examination showed limb dysmetria, marked gait imbalance with lateropulsion, and mild intermittent abducens paresis. Brain MRI revealed multiple small punctate and confluent T2/FLAIR hyperintense lesions with gadolinium enhancement predominantly involving the pons and cerebellar hemispheres, with additional foci in the left internal capsule, splenium of the corpus callosum, and supratentorial subcortical white matter, without significant edema. The initial impression was multifocal brain metastases, prompting extensive oncologic work-up including abdominopelvic CT, esophagogastroduodenoscopy, endoscopic ultrasound, and diagnostic laparoscopy, which demonstrated abdominal lymphadenopathy but no solid primary tumor or macroscopic peritoneal disease. Cerebrospinal fluid, infectious, autoimmune, and demyelinating studies were non-diagnostic, while cervical spine MRI revealed additional small enhancing lesions in the upper cervical cord and at C7–T1. After multidisciplinary review, the clinico-radiological picture was considered most compatible with CLIPPERS. Treatment with high-dose intravenous methylprednisolone followed by an oral prednisone dosage led to clinical improvement and a radiological response, with reduced size and number of supra- and infratentorial lesions and disappearance of some foci. This case highlights a probable CLIPPERS as an important metastasis mimic and underscores the value of early recognition of the steroid-responsive “peppering” pattern to guide work-up, avoid invasive procedures, and ensure long-term surveillance.