Table 1.

Guidelines for diagnosing myeloid sarcoma (MS).

Differential diagnosis	– Mature or immature types of MS: Hodgkin lymphoma, T-cell lymphoma; extramedullary hematopoiesis (myeloid metaplasia), or infectious processes; – Blastic type of MS: non-Hodgkin’s lymphoma, lymphoblastic lymphoma; poorly differentiated carcinoma, melanoma
Anatomical locations	Varied
Associated hematological malignancies	Acute myelogenous leukemia; chronic myelogenous leukemia; multiple myeloma; myelodysplastic syndrome; myelofibrosis
Histology (varied)	Mature and immature myelocytes; blasts; lack of bileneage or trileneage differentiation; extensive infiltration of surrounding tissue, or quite distinct
Cytochemistry: recommended stains	Myeloperoxidase; lysozyme; naphthol AS-D chloroacetate esterase; non-specific esterase
Immunophenotyping: recommended markers	– Most common: CD43 and CD68/KP1 – Other common: CD4, CD15, CD30, CD34, CD56, CD99, CD117, tdt, Glycophorin A, CD61/linker of activated T-lymphocyte/von-Willebrand antigen – Myeloid markers: CD68/KP1, CD117 – Monocytic markers: CD56, CD68, CD163 – T-cell markers: CD3, CD4, CD43, CD45, LCA – B-cell markers: CD20, CD79a
Cytogenetics: recommended evaluations should include	– Evaluate for monosomies, trisomies, translocations, and inversions: monosomy 7, monosomy 16, trisomy 8, trisomy 11, t(8;21)(p22;q22), inversion 16 – Particular deletions: 16q, 5q, 20q – Mutations commonly associated with acute myeloid leukemia: NPM1, FLT3-ITD