Lobar hemorrhages, when not due to an underlying mass or vascular lesion, are usually seen in the elderly in the setting of cerebral amyloid angiopathy (in this case confirmed on histology). 

Cerebral amyloid angiopathy can be divided according to the causative protein, of which there are many:

• sporadic
  • A-beta (APP) - ApoE e4 e2
• familial
  • A-beta (APP)
    • Dutch
    • Italian
    • Flemish
    • Swedish
  • cystatin C (ACys) - Icelandic  (20-30 years)
  • transthyretin (ATTR): meningovascular amyloidosis
  • gelsolin (AGel): finnish