Orbital Cavernous Malformation Connected to Sporadic Cerebral Cavernous Malformations via a Developmental Venous Anomaly: A Report of Two Cases.

Orbital cavernous venous malformations are isolated extradural vascular lesions with no known connection to intracranial pathology. We present two female patients with orbital cavernous malformations who were also found to harbor ipsilateral sporadic cerebral cavernous malformations. Using advanced 3T magnetic resonance imaging (MRI) sequences, including T1 3D dark blood, time of flight (TOF) 3D post-contrast, susceptibility-weighted imaging (SWI) with contrast enhancement, and 3D T1-weighted gradient echo (GRE) sequences, we identified in both cases an ectatic venous structure consistent with a developmental venous anomaly that traversed the superior orbital fissure, linking the orbital lesion to the intracranial venous system. Histopathological analysis of the surgically resected orbital lesion in the first patient confirmed the diagnosis of cavernous malformation. The information on the second patient relied solely on radiological analysis. Our findings indicate that a developmental venous anomaly may serve as a shared vascular conduit between orbital and intracranial cavernous malformations, challenging the view that orbital lesions arise in isolation. Screening for sporadic cerebral cavernous malformations should be considered in patients with orbital cavernous malformations when imaging demonstrates a developmental venous anomaly extending through the superior orbital fissure.