Lymphocytosis and Lymphoid Leukemias Flashcards
What is the lymphocyte count in a benign/non-clonal disorder verses a neoplastic/clonal disorder?
benign: ~10,000 or less
neoplastic: 20-40,000
Remember Normal range: 1,000-3,500
What are the lymphocytes doing in mononucleosis?
Cytotoxic T cells responding to EBV-infected B cells
What are the 3 PB smear criteria that must be met for a diagnosis of mononucleosis?
- > 50% mononuclear cells in diff
- marked lymphocytic heterogeneity
- > 10% reactive lymphocytes
Confirmation with heterophile antibody monospot test.
Typical reactive lymphocytoses
Polyclonal and demonstrate an admixture of kappa- and lambda-expressing B cells and CD4+ and CD8+ T cells
Lymphoid leukemia vs lymphoid lymphoma
Neoplastic lymphoid cell in the blood
Neoplastic lymphoid cells in tissue (LN, spleen, liver)
CD34+ CD10+ TDT+ CD19+ CD20-
B-ALL
CD3+
CD4-8 dual+
TDT+
T-ALL
Lymphocytosis of small lymphs with round nuclei and “soccer ball” or “gingersnap” chromatin
CLL/SLL
CD5+
CD19+
CD23+
CLL/SLL
Lymphocytes with “hairy” cytplasmic projections and reniform nuclei
Hairy cell leukemia
CD19+
CD20+
CD11c+
CD22 bright +
Hairy cell leukemia
TRAP + cells
Found in hairy cell leukemia
Positive for tartrate-resistant acid phosphatase
Also, cells “trapped” in red pulp and bm –> cannot get to lymph node –> splenomegaly d/t accumulation
Dry tap on bm aspiration
HTLV-1 provirus in tumor cells
Adults with skin lesions, HSM, LAD and hypercalcemia
Common in Japan and Caribbean
Rapidly progressive
“flower” cells, helper T cells, CD25+ CD4+
Adult T-cell leukemia/lymphoma (ATLL)
Adult patients with cutaneous patches, plaques
Or generalized erythema and LAD
Lymphocytes with cerebriform nuclei and powdery chromatin in skin or blood
Mycosis fungoides/Sezary syndrome
Adult patients with neutropenia, anemia, splenomegaly
May be assoc with autoimmune disorder (RA); indolent
Lymphocytes with eosinophilic granules; cytotoxic T cells CD8+
T-cell large granular lymphocytic leukemia (LGLL)
