Boomerang sign in the corpus callosum and bilateral cerebellar peduncles: CLOCCs plus—a case report

Cytotoxic lesions of the corpus callosum (CLOCCs) are a clinically and radiologically defined syndrome that can develop due to a wide range of etiologies, including infections, epileptic seizures, metabolic disorders, drug toxicity, malignancies, cerebrovascular diseases, and other systemic conditions. These lesions are mostly reversible but may be permanent in some cases. Although CLOCCs are typically characterized by boomerang-shaped diffusion-restricted lesions in the splenium of the corpus callosum, recent reports have shown that similar lesions can also appear in other vulnerable brain regions outside the corpus callosum and may share the same pathophysiological mechanism. Therefore, in this study, we present a rare case consistent with CLOCCs plus syndrome, showing simultaneous boomerang-shaped lesions in both the splenium of the corpus callosum and the bilateral middle cerebellar peduncles.