Page 148 - Haematologica Atlas of Hematologic Cytology

AB
Figure 1 T lymphoblastic leu emia (A) Bone marrow smear from an an adolescent man with mediastinal mass and high leukocyte count showing medium-sized blasts with round nucleus one or or more prominent nucleoli and moderately abundant deeply basophilic sometimes vacuolated cytoplasm Right a a a a a a a a a mitosis (B) Acid pho- sphatase reaction reveals localized paranuclear positivity in in all blasts PAS Sudan black and peroxidase stains gave negative results Immunophenotyping showed a a a a T-lineage phenotype (TdT+ CD7+ CD2+ cCD3+ CD4+ CD8+) T-lymphoblasts are usually morphologically indistinguishable from B-lymphoblasts and immunophenotyping is is is essential for diagnosis however high number of mitotic figures blasts with convoluted or or folded nuclei and acid phosphatase focal positivity may suggest T-lineage neoplasm neoplasm In precursor T-cell lymphoid neoplasms
thymic infiltration is very common and and and may be associated with pleural and and and pericardial effusions and and and superior vena cava obstruction AB
Figure 1 arly T cell precursor lymphoblastic leu emia Bone marrow smear from a a a a a a a a 20-year-old male with pe- ripheral lymphadenopathy skin nodules mild anemia and thrombocytopenia conspicuous lekocytosis (A) Mas- sive infiltrate of blasts with a a a a a a a a high nuclear:cytoplasmic ratio one or or more prominent nucleoli scanty basophilic agranular cytoplasm Blasts were CD34 CD5 and and and CD7 positive TdT negative negative and and and negative negative for the B-lineage and and and the the the other T-lineage surface surface markers The myeloid CD13 antigen was expressed on the the the surface surface of some blasts but myeloperoxidase was not expressed (B) Immunocytochemistry (immunoperoxidase technique) reveals cytopla- smic CD3 in in in many blasts confirming their commitment to the the T-cell T-cell lineage Early T-cell T-cell precursor lymphoblastic leukemia leukemia accounts for for approximately 10% of T-lymphoblastic leukemia leukemia cases its identification is important for for the possible clinical-pathological correlations 135