Myeloid sarcoma

extramedullary myeloid tumour (myeloid sarcoma, granulocytic sarcoma, chloroma)

Myeloid sarcoma is a tumour mass which consists of myeloid blasts and is seen at anatomical sites other than the bone marrow e.g. - most commonly in skin, lymph nodes, gastrointestinal tract, bone, soft tissue, and testis (1).

Myeloid sarcoma may arise:

• de novo as a primary manifestation of AML in patients with no medullary evidence of leukaemia
• simultaneously with marrow disease at presentation;
• as an isolated focus of relapse " simultaneously with marrow disease at relapse (2)

Predisposing factors of extramedullary disease include:

• t(8;21) translocation or inv(16)
• high presenting white cell count
• lack of Auer rods
• poor nutrition (1)

Diagnosis is established through cytochemical and/or immunohistochemical analyses (1). Systemic antileukaemic chemotherapy should be given to patients who present with de novo or in relapse with extramedullary leukaemia. Surgical or radiotherapeutic approaches should be reserved for patients whose disease does not resolve with initial therapy (2).

Reference:

• 1. Döhner H et al. Diagnosis and management of acute myeloid leukemia in adults: recommendations from an international expert panel, on behalf of the European LeukemiaNet. Blood. 2010;115(3):453-74.
• 2. British Committee for Standards in Haematology et al.Guidelines on the management of acute myeloid leukaemia in adults. Br J Haematol. 2006;135(4):450-74.