Background: Dural-based cavernous malformations are rare and have been more commonly described in the middle fossa. Fewer than 20 cases outside of the middle fossa have been reported and they often mimic more commonly found lesions such as meningiomas or hemangiopericytomas.
Case description: We describe the unusual case of a right frontal convexity dural cavernous malformation with intradural and extradural components as well as erosion through the calvarium. The patient underwent a right frontal craniotomy and en-bloc resection of the mass. Final pathologic interpretation confirmed a cavernous malformation that had eroded through the calvarium.
Conclusion: Dural-based cavernous malformations are a rare entity, but should be considered in the differential diagnosis of atypical appearing dural-based lesions and soft subgaleal masses. If atypical features are present, further radiographic investigations should be undertaken. To our knowledge, this is the only reported case of a dural-based cavernous malformation eroding through the calvarium and presenting initially as a soft scalp mass.