Mnemonic for Differential Diagnosis of Lucent and Lytic bone lesions

We have two super useful mnemonics for the differential diagnosis of lucent/lytic bone lesions :

  • FEGNOMASHIC
  • FOG MACHINES

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

Mnemonics

FEGNOMASHIC
  • F: fibrous dysplasia (FD) or fibrous cortical defect (FCD)
  • E: enchondroma or eosinophilic granuloma (EG)
  • G: giant cell tumor (GCT) or geode
  • N: non-ossifying fibroma (NOF)
  • O: osteoblastoma
  • M: metastasis(es)/myeloma
  • A: aneurysmal bone cyst (ABC)
  • S: simple (unicameral) bone cyst
  • H: hyperparathyroidism (brown tumor)
  • I: infection (osteomyelitis) or infarction (bone infarction)
  • C: chondroblastoma or chondromyxoid fibroma
Lucent/Lytic 
Bone Lesion 
Differential Diagnosis
Another good mnemonic for causes of Lytic Bone lesions is FOG MACHINES
  • 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
Lucent/Lytic 
Bone Lesion 
Differential Diagnosis

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

Hope those two mnemonics will make your life easier. For more medical mnemonics, check out our MNEMONICS section.

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