Precursor B Lymphoblastic Lymphoma Differential Diagnosis
Both are TdT+ and may be CD34+
Burkitt Lymphoma
Lymphoblastic Lymphoma, T and B
Median age 30 years
Median age 17-20 years
B lineage markers positive
90% T, 10% B
Multiple nucleoli
Inconspicuous nucleoli
Coarse chromatin
Fine chromatin
Thin rim of cytoplasm
Scant cytoplasm
Frequently GI or ovary
T frequently mediastinal, B frequently cutaneous
TdT negative
TdT virtually always positive
Translocation involving myc gene
No myc translocation
Both have extremely high mitotic rates and starry sky macrophages although Burkitt lymphoma typically has a higher mitotic rate and the starry sky pattern is more uniform
Lymphoblastic Lymphoma, T or B
Blastic Mantle Cell Lymphoma
Median age 17-20 years
Rare under 30 years
Histiocytes infrequent (tingible body macrophages frequent)
Scattered histiocytes frequent
No prior diagnosis of mantle zone lymphoma
Frequent diagnosis of mantle zone lymphoma
T lineage 90%, B lineage 10%
B lineage markers positive
bcl1 negative
bcl1 85%
CD5 negative if B lineage
CD5 80%
Lymphoblastic Lymphoma, B or T
Extramedullary Myeloid Tumor
90% T lineage, 10% B lineage
CD43+ but other T and B markers negative
Myeloperoxidase negative
Myeloperoxidase >90%
Lysozyme negative
Lysozyme 90%
Lymphoblastic Lymphoma, B or T
DLBCL
Median age 17-20 years
Median age 60 years
90% T lineage, 10% B lineage
B lineage
Starry sky macrophages present
Starry sky pattern infrequent
Fine chromatin
Vesicular chromatin
None or small nucleoli
May have prominent nucleoli
Uniform cells
Heterogeneous cells
Generally only a problem in suboptimally processed specimens
Lymphoblastic Lymphoma, B or T
SLL/CLL
Median age 17-20 years
Rare under 30 years
Starry sky macrophages frequent
Starry sky macrophages rare
High mitotic rate
Mitoic figures only in proliferation centers
T lineage 90%, B lineage 10%
B lineage
CD23 negative
CD23 85%
Generally only a problem in suboptimally prepared specimens in which cytologic detail is obscured
Rhabdomyosarcoma
PPNET
Neuroblastoma
Lymphoblastic Lymphoma, B or T
Muscle markers
positive
negative
negative
negative
CD99
positive
negative
negative
positive
LCA and or B/T lineage
negative
negative
negative
90% T, 10% B
TdT
negative
negative
negative
positive
Cytoplasm
abundant, eosinophilic
scant
fibrillar
scant