Granulocytic sarcoma

From Dog
A rapidly emerging rectal chloroma in association with monocytic leukemia in a dog[1]

Granulocytic sarcoma (myeloid sarcoma; chloroma) are an extramedullary neoplastic disease of dogs involving immature myeloid cells or myeloblasts and usually occurs in association with leukemia as an initial presentation or a recrudescence[2].

An underlying genetic mutation is thought to be responsible for the manifestation of these tumors.

These tumors often present as skin tumors, often located in the neck and truncal region.

A differential diagnosis would include hemangiopericytoma, mastocytoma and histiocytoma.

Although surgical extirpation is usually curative, underlying hematopoietic neoplasia should be entertained.


  1. Thakar MS et al (2009) Transmission and expansion of HOXB4-induced leukemia in two immunosuppressed dogs: implications for a new canine leukemia model. Exp Hematol 37(10):1157-1166
  2. Mayr B et al (1999) Cytogenetic, ras, and p53: studies in cases of canine neoplasms (hemangiopericytoma, mastocytoma, histiocytoma, chloroma). J Hered 90(1):124-128