Hematopathology and Lymphoid Neoplasms

Vocabulary practice flashcards covering hematopoiesis, lineage-specific cluster of differentiation (CD) markers, platelet granules, histiocytosis, leukemias, and lymphomas based on lecture notes.

CD34

A cell surface marker identifying hematopoietic stem cells and early myeloid progenitor cells.

CD45

The leukocyte common antigen expressed on white blood cells.

Erythroblast Markers

Characterized by $CD71$ expression and diffuse $PAS$ positivity.

Megakaryoblast Markers

Characterized by the expression of $CD41$, $CD42$, and $CD61$.

Platelet Alpha Granules

Granules containing Fibrinogen, Fibronectin, von Willebrand factor (vWF), and Platelet Factor 4 (PF-4).

Platelet Delta (Dense) Granules

Granules containing ADP, Serotonin, Histamine, and Calcium.

Myeloblast Markers

Characterized by the expression of myeloid lineage markers $CD13$, $CD33$, and $CD117$.

Monocyte and Monoblast Markers

Characterized by $CD14$ and $CD64$ expression, showing Non-Specific Esterase (NSE) positivity.

Lymphoblast Markers

Characterized by $TdT$, $CALLA$ ($CD10$), and dot/block $PAS$ positivity.

Pan-B Cell Markers

Antigenic markers and transcription factors including $CD10$, $CD19$, $CD20$, $CD21$, $CD23$, $CD79a$, and $PAX-5$.

Pan-T Cell Markers

Surface markers defining T lymphocytes, including $CD1$, $CD3$, $CD4$, $CD5$, $CD7$, and $CD8$.

Natural Killer (NK) Cells

Lymphocytes expressing $CD16$, $CD56$, and $CD94$ that destroy target cells lacking $MHC\,I$.

Plasma Cell Markers

Terminally differentiated B cells characterized by $CD38$, $CD138$ (Syndecan-1), and $CD56$.

MHC Class I

Surface molecule expressed on all nucleated cells that presents antigen to $CD8+$ cytotoxic T cells.

MHC Class II

Surface molecule expressed on antigen-presenting cells (B cells, macrophages, dendritic cells) that interacts with $CD4+$ helper T cells.

Langerhans Cell Histiocytosis (LCH) Markers

Characterized by immunophenotypic positivity for $CD1a$, $CD207$ (Langerin), and $S-100$.

B-ALL (B-cell Acute Lymphoblastic Leukemia)

Precursor B-cell neoplasm expressing $CD19$, $CD20$, $CD22$, and $TdT$, associated with loss-of-function mutations in $PAX-5$, $EBF$, $E2A$, and $RUNX1$.

T-ALL (T-cell Acute Lymphoblastic Leukemia)

Precursor T-cell neoplasm expressing $CD3$, $CD5$, and $CD7$, commonly associated with gain-of-function mutations in $NOTCH-1$.

Hairy Cell Leukemia Markers

Indolent B-cell disorder characterized by positivity for $CD11c$, $CD19$, $CD20$, $CD25$, $CD103$, and Annexin A1.

SLL / CLL (Small Lymphocytic Lymphoma / Chronic Lymphocytic Leukemia)

B-cell NHL characterized by $CD5(+)$, $CD23(+)$, $CD43(+)$, and $CD200(+)$, commonly featuring a $13q$ deletion.

Mantle Cell Lymphoma

Aggressive B-cell NHL that is $CD5(+)$ and $CD23(-)$, expressing Cyclin D1 and Sox-11 due to $t(11;14)$.

Follicular Lymphoma

Germinal center B-cell lymphoma that is $CD5(-)$, $CD23(-)$, $CD10(+)$, $Bcl-2(+)$, and $Bcl-6(+)$, characterized by translocation $t(14;18)$.

Burkitt Lymphoma

Aggressive B-cell lymphoma expressing $CD10$ and $Bcl-6$, associated with $MYC$ translocations $t(8;14)$, $t(2;8)$, and $t(8;22)$.

Anaplastic Large Cell Lymphoma (ALCL)

T-cell lymphoma positive for $CD30$ and associated with $t(2;5)$ involving the $ALK$ gene on chromosome $2p$.

Classical Hodgkin Lymphoma Markers

Characterized by neoplastic Reed-Sternberg cells positive for $CD15$, $CD30$, and dim $PAX-5$.

Non-Classical Hodgkin Lymphoma Markers

Nodular lymphocyte predominant subtype characterized by positivity for $CD20$, $CD45$, $Bcl-6$, and $EMA$.