Fibrous Cortical Defect Metacarpal

10yr old boy history of fall, shows cortical lucency of 3rd metacarpal

Teaching point by Dr MGK Murthy.

• Both non-ossifying fibroma (fibroxanthomas) and fibrous cortical defects are composed of spindle shaped fibroblasts in a cartwheel pattern with scattered giant cells, foam cells and collegan along with abundend hemosiderin, cholestrol christals in the cytoplasm of fibroblasts.
• Very common incidental radiographic lesion (caffey reported 36 % in population) in asymptomatic children with slight male predominance.
• Usually present 4 to 8 years age, with peak incidence 10 to 15 years.
• 90 % occur in tubular long bones with commonest sites being, distal femoral, proximal and distal tibial and around the knee with upper extremity being an uncommon site. however cases are reported in the innominate bone, clavical, skull, scapula, mandible and small bones of hands and feet.
• Typically metaphyseal and close to physeal plate.
• The FCD arises within the cortex where as NOF arises eccentrically within the medullary cavity, with multiplicity being moe common with FCD.
• Both arise from the posterior wall of the tubular bone and involvement of medial rather than lateral osseous surface is characteristic.
• May involute and disappear or persist into adult life with epiphyseal location rare.

D/D :- Include chondromyxoid fibroma, fibrous dysplasia, osteoid osteoma, bone abscess, periosteal chondroma, avulsive cortical irregularity, periosteal desmoid fibromatosis, desmoplastic fibroma, cortical avulsive injury.

The presence of extraskeletal congenital anomalies like cafe-as-lait spots, mental retardation, hypogonadism or cryptorchidism, cardiovascular malformations in association with multiple nonossifying fibroxanthomas constitute the  Jaffe-Campanacci syndrome.