Lymph nodes & spleen, nonlymphoid
Lymph nodes-nonlymphoid neoplasms
Myeloid sarcoma


Topic Completed: 1 June 2006

Minor changes: 5 July 2020

Copyright: 2003-2020, PathologyOutlines.com, Inc.

PubMed Search: Acute myeloid leukemia granulocytic sarcoma[TIAB] lymph node

See also: Bone marrow neoplastic chapter

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Cite this page: DePond W. Myeloid sarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphnodesAML.html. Accessed July 5th, 2020.
Definition / general
  • Also called granulocytic / myeloid sarcoma or chloroma when it forms a mass
  • Diagnosis requires a high degree of suspicion; thin sections are needed to see cytoplasmic granules
  • Lymphadenopathy may be initial presentation, preceding marrow involvement by months or years
  • May present with nodal infarction (Am J Surg Pathol 1989;13:177)
Case reports
Gross description
  • May have green hue ("chloroma") due to myeloperoxidase, which fades on exposure to air
Gross images

Contributed by Mark R. Wick, M.D.

Granulocytic sarcoma



Images hosted on other servers:

Retroperitoneal lymphadenopathy

Subcutaneous tumor

Microscopic (histologic) description
  • Cortical or sinusoidal expansion by atypical cells with preservation of follicular centers
  • Blasts are large to medium size with distinct cytoplasmic borders and fine cytoplasmic granules
  • Nuclei have round, folded or lobated nuclei, fine and dispersed chromatin and small to prominent nucleoli
  • Often infiltrate in a single file pattern due to tumor cells insinuating between collagen fibers
  • Often associated with eosinophilic myelocytes
  • Auer rods may be present (Giemsa stain)
  • Variable mitotic figures
  • May have associated prominent sclerosis
Microscopic (histologic) images

AFIP images

Granulocytic sarcoma

Acute myeloid leukemia

Involving liver

With interspersed eosinophilic myelocytes

Cytology description
  • Cytoplasmic granules in many cells
Cytology images

AFIP images

Cytologic spectrum

Positive stains
(On blasts, not other inflammatory cells)
Electron microscopy description
  • Large electron dense primary cytoplasmic granules and less dense secondary granules
  • May have ellipsoidal crystalloid granules
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