Cerebellar Cysts in Children: A Pattern-Recognition Approach

Aims: Neuroimaging plays a key role in the diagnostic work-up of congenital posterior fossa abnormalities. Cerebellar cysts are rather uncommon findings in pediatric neuroimaging and may be seen in selected disorders of both malformative and disruptive etiology. Here, we summarize our experience with cerebellar cysts and review the available literature.

Methods: We qualitatively analyzed the neuroimaging studies of children with known cerebellar cysts. We focused on the size, shape, and location (cortical–subcortical, within the white matter, and focal or widespread) of the cerebellar cysts as well as additional neuroimaging findings within the posterior fossa (morphology of cerebellum and brain stem) and supratentorial brain (e.g., migration anomalies, white matter signal abnormalities, hydrocephalus, and white matter cysts). We excluded cystic cerebellar tumors (such as, low-grade gliomas and hemangioblastomas), parasitic cysts (such as, echinococcus cysticus and alveolaris, and neurocysticercosis), or posttraumatic and postsurgical cysts.

Results: We classified the diseases with cerebellar cysts into broad categories based on the underlying pathomechanism: normal cystic structures (cystic perivascular spaces in mucopolysaccharidoses), isolated cysts (e.g., neuroglial cysts), destructive cysts in some types of pontocerebellar hypoplasia, malformative cysts (e.g., congenital muscular dystrophies, Aicardi syndrome, GPR56 mutation, and LAMA1 mutation), cysts associated with cerebellar dysplasia (e.g., Cohen syndrome, disruptive [cysts confined to a unilateral, dysplastic hemisphere of reduced volume], and unknown), and a group including various diseases such as leukoencephalopathy with calcifications and cysts and early-onset multiple carboxylase deficiency.

Conclusion: We provide a classification of diseases associated with cerebellar cysts. This classification allows a neuroimaging-based pattern recognition approach and takes the clinical information into account. The provided classification may be useful in deciding targeted diagnostic work-up.

Keywords: cerebellum, cysts, MRI, congenital muscular dystrophy.