ALL L3 morphology is a malignancy arising from which cell lineage –: (A) Mature B cell, (B) Precursor B cell, (C) Immature T cell, (D) Mixed B cell & T cell
Answer is A. Cellular classification of ALL 
French-American-British (FAB) system divides ALL into three morphological subtypes.
i) LI lymphoblasts

Most common type (80-85%)
Cells have scanty cytoplasm and inconspicuous nucleoli.
Have better prognosis

ii) L2 lymphoblasts

Cells are large and more pleomorphic in size with more abundant cytoplasm and prominent nucleoli.

iii) L3 - lymphoblast

Least common
Morphology is identical to urkitt's lymphoma cells i.e., mature B cells with surface immunoglobulin positive.