DDx critera for "benign" lytic bone lesions
F E G N O M A S H I C
| F | Fibrous dysplasia | No periosteal rxn. If in tibia mention adamantinoma. |
|---|---|---|
| E | Echondroma Eosinophilic granuloma |
Must have calcification, except in phalanges. No periostitis. E. Granuloma must be under 30 |
| G | Giant cell tumour | (1)Epiphysis closed (2)Must abut the articular surface (3)Eccentric (4)Well defined, non-sclerotic border |
| N | Nonossifying fibroma | Must be under 30. No periostitis |
| O | Osteoblastoma | DDx ABC over 30 years |
| M | Mets or myeloma | Over 40 |
| A | Aneyrysmal bone cyst | ABC must be under 30. Expansile. |
| S | Solitary bone cyst | Must be centrally located, under 30. |
| H | Hyperparathyroidism | "Brown tunour". Other evidence of hyperparathyroidism |
| I | Infection | If adjacent to joint, "must" involve joint |
| C | Chondroblastoma Chondromyxoid fibroma |
Must be under 30. Epiphyseal DDx nonossifying fibroma |