Lucent/lytic bone lesion - differential diagnosis (mnemonic)

Mnemonics for the differential diagnosis of lucent/lytic bone lesions include:


They are anagrams of each other and therefore include the same components. They are by no means exhaustive lists, but are a good start for remembering a differential for a lucent/lytic bone lesion and will suffice for >95% of the time 1.


  • F: fibrous dysplasia (FD) or fibrous cortical defect (FCD)
  • O: osteoblastoma
  • G: giant cell tumor (GCT) or geode
  • M: metastasis(es)/myeloma
  • A: aneurysmal bone cyst (ABC)
  • C: chondroblastoma or chondromyxoid fibroma
  • H: hyperparathyroidism (brown tumor)
  • I: infection (osteomyelitis) or infarction (bone infarction)
  • N: non-ossifying fibroma (NOF)
  • E: enchondroma or eosinophilic granuloma (EG)
  • S: simple (unicameral) bone cyst

These lists are not exhaustive (e.g. intraosseous lipoma is omitted)

Related articles

Article information

rID: 4501
Section: Mnemonics
Synonyms or Alternate Spellings:
  • FOGMACHINES (mnemonic)
  • FOG MACHINES (mnemonic)
  • FEGNOMASHIC (mnemonic)
  • Mnemonic for lytic bone lesions

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Cases and figures

  • Case 1: metastasis - RCC
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