Isolated, severe cerebellar hypoplasia and microcephaly secondary to congenital cytomegalovirus infection in a late preterm neonate.

This case report presents a late preterm infant diagnosed with severe cerebellar hypoplasia and microcephaly secondary to congenital cytomegalovirus (cCMV) infection. Initially suspected to have Dandy-Walker malformation, postnatal MRI revealed significant cerebellar hypoplasia, without other typical cCMV findings. The diagnosis was confirmed by the presence of CMV in serum and urine. The patient was started on valganciclovir for 6 months, and despite the significant cerebellar hypoplasia, the clinical course was benign, with normal respiratory and feeding functions. Physical examination showed microcephaly, hypotonia and partial bilateral hearing loss. Follow-up showed persistent hypotonia but normal developmental progression otherwise. This case is notable for isolated cerebellar hypoplasia without other common cCMV-related radiological abnormalities, highlighting the need for further exploration into the atypical presentations of cCMV.