By Anastazia Hartman

Medulloblastomas are one of the most common types of childhood brain cancer. Thanks to Dr. Sriram Venneti, MD, PhD and his colleagues, there has been a recent breakthrough in group-3 and group-4 medulloblastomas, a tumor that appears during fetal development of the cerebellum. 

Alongside collaborating investigators Dr. Elaine Mardis, PhD, Nationwide Children’s Hospital, and Dr. Michael Taylor, MD, PhD Texas Children’s
Hospital, the group was able to determine that group-3 and group-4 medulloblastomas arise from aberrant/arrested brain tissue in the rhombic lip. This then develops into a structure called the nodulus, rare atypical cells, that are called heterotopias. In this breakthrough, Drs. Venneti, Mardis, and Taylor also proposed a new designation for heterotopias, naming them Persistent Rhombic Lips (PeRLs). Their hypothesis is to identify if PeRLs represent premalignant lesions for group-3 and group-4 medulloblastomas.

To test this, the group will evaluate brain tissue from autopsies to determine the frequency of PeRLs, identify co-morbidities, and asses for potential PerRLs to transform into malignant tumors. The use of Next-Generation sequencing will be used to determine the characteristics of PeRLs in comparison to normal cerebellar tissue. 

Thanks to the work of the collaborators, this is one of the first studies looking to establish the prevalence of PeRLS in the general population, help evaluate the potential for progression to malignancy, and determine if there is a unique way to detect pre-cancerous lesions that, in turn, could lead to implementing screening for biomarkers that identify deadly childhood brain cancers.