Hyperintense perilesional edema in the brain on T1-weighted images: Cavernous malformation or metastatic melanoma? Three case reports and literature review.

Hyperintense perilesional edema in brain masses on T1-weighted images (T1WI) is an unusual radiological finding. We report three cases showing this particular type of edema, one representing cerebral hemorrhagic cavernous malformation (CCM, cavernoma) and the other two, metastases of melanoma. The association between this sign and cavernoma was recently recognized. On the other hand, in melanotic lesions, the relationship with T1WI-hyperintense perilesional edema has not yet been described. Despite being an infrequent sign, it can considerably narrow the differential diagnosis, which gives it a high value for clinical practice. Moreover, given the high prevalence of the entities that manifest this imaging feature, it can be occasionally noticed.