This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acute Lymphoblastic Leukemia, Subject name: Pathology
Acid phosphastase cytochemical staining is used in the diagnosis of which of the following hematological neoplasms? 
Select and explain. 
A. Chronic myeloid leukemia, B. Acute myeloid leukemia, C. B-cell acute lymphoblastic leukemia, D. T-cell acute lymphoblastic leukemia
D: T-cell acute lymphoblastic leukemia
Answer: D: T-cell acute lymphoblastic leukemia 
Explanation: 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).