Granulocytic sarcoma

Granulocytic sarcoma (also called myeloid sarcoma and chloroma) is a rare neoplasm comprised of myeloid precursor cells.

It is typically seen is in children with ~60% occurring in individuals less than 15 years of age. There is no recognised gender predilection.

Granulocytic sarcoma may develop during the course of a haematologic disorder, but is seen to precede the disorder in 35% of cases.

Granulocytic sarcoma lesions are composed of immature myeloid elements and therefore represent focal accumulation of leukaemic cells. In contrast to its associated entities, the lesion(s) take the form of a solid soft tissue mass(es).

Being extramedullary is a key feature.

Almost any tissue can be affected, with skin and bone being the commonest. They have been reported in the skull, face, orbit, and paranasal sinuses. Lesions have been reported in the tonsils, oral and nasal cavities and within the lacrimal, thyroid and salivary glands. The central nervous system can also be affected.

It can occur in association with:

Exact imaging features will depend on the location and involved organ. Please refer to:

  • first described by A Burns in 1811 3
  • termed "chloroma" in 1853 by King due to typical forms have a green colour from high levels of myeloperoxidase in immature cells
  • renamed as granulocytic sarcoma in 1966 by Rappaport when it was demonstrated that an estimated 30% of cells do not contain myeloperoxidase, therefore, a significant proportion of cells are not green in colour
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Article information

rID: 10568
Synonyms or Alternate Spellings:
  • Chloroma
  • Myeloid sarcoma
  • Extramedullary myeloblastoma

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Cases and figures

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    Chloroma CT
    Case 1: CT
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    Chloroma FLAIR
    Case 1: MRI
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    Chloroma CT 7 Wee...
    Case 1: follow up at 7 weeks post treatment
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    Case 2
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    Case 3: spinal involvement
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