Feature | Unifocal (isolated) VM | Multifocal sporadic VM | VMCM | BRBN syndrome |
ISSVA classification | Common VM | Familial VM cutaneo-mucosal | BRBN (Bean) syndrome |
Molecular etiology | Somatic (mosaic or acquired) pathogenic variant | Somatic pathogenic variant (acquired early in embryogenesis) + second mosaic (acquired) pathogenic variant | Germline (inherited) + somatic (acquired) pathogenic variant | Somatic (acquired) pathogenic variant + second somatic (acquired) pathogenic variant |
Clinical features | - Slow-flow blood vascular lesion
- Light to dark skin discoloration overlying a soft, often compressible mass that develops primarily in cutaneous, subcutaneous, or mucosal tissues
| - Light to dark skin discoloration overlying a soft, often noncompressible mass that develops primarily in cutaneous, subcutaneous, or mucosal tissues
| - Nipple-like, bluish nodules with a rubbery consistency
- Tend to aggregate and become hyperkeratotic with time
|
Proportion of all VMs | >90% | Rare (estimated to be approximately 1%) |
Location | - 40% on the extremities
- 40% in the cervicofacial area
- 20% on the trunk
| - All over the body
- Skin and oral mucosa
- Rare on palms and soles
| - All over the body
- Skin and oral mucosa
- Rare on palms and soles
| - All over the body
- Skin and mucosa
- Predilection for the palms and soles
- Typically, a large dominant lesion is present at birth
|
Size | Highly variable | <5 cm | <5 cm | <2 cm |
Gastrointestinal lesions | - Gastrointestinal lesions may or may not occur
| | - Multiple VMs located in the small intestines (pathognomonic)
- Can cause bleeding and chronic anemia
- Complications include intussusception, volvulus, and intestinal infarction
|
Coagulopathy | Approximately 40% (depending on the size and extent of the lesion[s]) | Common (≥80%) | Common (>80%) |