Non specific esterase in present in –
Megakaryocytic leukaemia
Lymphocytic leukaemia
Erythroleukaemia
AML
Acute Myelogenous leukemia (AML)

AML is a cancer of myeloid line of WBCs, characterized by the rapid proliferation of abnormal cells which accumulate in the bone marrow and interfere with the production of normal blood cells.
AML is the most common acute leukemia affecting adults.
The diagnosis of AML is based on finding that myeloid blasts make up more than 20% of the cells in the marrow.

Mveloblasts are inyeloperoxidase (peroxidase) positive. 

Auer rods (Represent abnormal azurophilic granule) are also present in myeloblasts and their presence is taken to be definite evedence of myeloid differentiation.
In some AMLs, blast cells exhibit differentiation of other myeloid stem cell line (other than myeloblast), e.g.,

i)  Monoblast → Lack aver rods, peroxides negative, but nonspecific esterase positive.
ii). Megakaryocytic differentiation
iii) Erythroblast