Acid phosphastase cytochemical staining is used in the diagnosis of which of the following hematological neoplasms?: (A) Chronic myeloid leukemia, (B) Acute myeloid leukemia, (C) B-cell acute lymphoblastic leukemia, (D) T-cell acute lymphoblastic leukemia
Answer is D. Cytochemically demonstrable acid phosphatase has main diagnostic use is in the diagnosis of T-cell ALL and hairy cell leukaemia. In T cells, acid phosphatase is an early differentiation feature. Almost all acute and chronic T-lineage leukaemias show strong activity. In T-lineage ALL, the activity is usually highly localised (polar).