Vascular malformation rupture in a patient affected by Costello syndrome

Area of Science:

• Genetics
• Vascular Biology
• Rare Diseases

Background:

• Costello syndrome (CS) is a rare genetic disorder typically caused by HRAS gene mutations within the RAS/MAPK pathway.
• RAS/MAPK pathway dysregulation is implicated in various cellular processes, including vascular development and integrity.

Observation:

• A male patient with Costello syndrome presented with a painful, pulsatile wrist mass.
• Initial ultrasonography suggested a radial artery aneurysm, but surgical findings revealed a vascular malformation (VM).
• Histological and immunohistochemical analyses indicated abnormal vascular wall structure with poor endothelial contribution.

Findings:

• The wrist mass was definitively diagnosed as a ruptured acute vascular malformation, distinct from a typical arterial aneurysm.
• The histological features suggest a congenital vascular anomaly rather than a degenerative process.

Implications:

• Patients with Costello syndrome may be predisposed to developing vascular malformations due to HRAS/RAS/MAPK pathway mutations.
• Acute onset of pulsatile masses in CS patients should raise suspicion for ruptured VMs, necessitating prompt diagnosis and management.
• This case highlights the importance of considering vascular malformations in the differential diagnosis of arterial lesions in CS patients.