= SYNOVIAL HERNIATION PIT = CONVERSION DEFECT

= ingrowth of fibrous + cartilaginous elements from adjacent joint through perforation in cortex

Histo: fibroalveolar tissue

Age: usually in older individuals

• may be symptomatic; no clinical significance

Location: anterior superolateral aspect of proximal femoral neck; uni- or bilateral

Site: subcortical

Size: usually <1 cm in diameter; may enlarge over time

• well-circumscribed round lucency
• reactive thin sclerotic border
• hyperintense area on T2WI (= fluid signal intensity)
• bone scan may be positive