Leukoencephalopathy With Calcifications and Cysts

A 52-year-old woman presented with progressive encephalopathy, quadriparesis, and seizures over 6 months.Family history was unrevealing.Head CT revealed white matter hypodensities, basal ganglia calcifications, and a posterior fossa cystic lesion (Figure 1).Brain MRI showed diffuse T2/FLAIR white matter hyperintensities sparing U-fibers, basal ganglia calcifications, and a large pontine cystic lesion (Figure 2).CSF studies were normal.Trio-based whole-exome sequencing revealed previously reported pathogenic variants in SNORD118, 1 consistent with a diagnosis of leukoencephalopathy with calcifications and cysts (LCC). 2 LCC is an extremely rare genetic leukoencephalopathy caused by autosomal recessive pathogenic variants in the SNORD118 gene. 2 Typical radiographic findings are leukoencephalopathy sparing U-fibers, deep grey matter calcifications, and cystic lesions. 1,2Pathologic findings include a microangiopathy with angiomatous-like blood vessel gliosis and Rosenthal fiber deposition. 2 Case reports document response to bevacizumab, although there is an increased risk of hemorrhage within cysts and some patients have spontaneous arrest of disease progression.