Lucent/lytic bone lesion - differential diagnosis (mnemonic)

Last revised by Craig Hacking on 17 Apr 2024

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) or intraosseous lipoma

  • N: non-ossifying fibroma (NOF)

  • E: enchondroma or eosinophilic granuloma (EG)

  • S: simple (unicameral) bone cyst

History and etymology

The earliest reference to FEGNOMASHIC in the literature seems to be from a paper published by a group of radiologists at University of California in 1972, which was itself based on work presented at the Scientific Assembly and Annual Meeting of the Radiological Society of North America in 1971. Its invention likely predates this, however its origin remains obscure. It was certainly not invented by the renowned musculoskeletal radiologist Clyde Helms, as some claim, not least because Helms himself stated that he was taught it whilst in the Air Force, before he had even started his radiology residency 1,3!

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