Flashcards in Lymph Nodes Deck (343)
Examples of "double-hit" lymphomas with acquired mutations of MYC (4).
Diffuse large B-cell lymphoma.
"Double-hit" lymphoma arising from follicular lymphoma: Possible histologic features (6).
Absence of centrocytes.
Very high proliferation.
Angioimmunoblastic T-cell lymphoma: Typical patient.
Elderly adult with organomegaly and "B" symptoms.
Angioimmunoblastic T-cell lymphoma: Less common signs and symptoms (4).
Pleural effusion, ascites.
Angioimmunoblastic T-cell lymphoma: Prognosis.
Angioimmunoblastic T-cell lymphoma: Architecture (4).
Partial effacement of lymph node.
Paracortical location of tumor cells.
Paracortical vascular proliferation (high-endothelial venules).
Expansion of FDC meshworks (demonstrable by IHC for CD21, CD23).
Angioimmunoblastic T-cell lymphoma: Cells (2).
Tumor cells: Atypical, small to medium-sized, moderate amount of clear cytoplasm.
Other cells: Reactive small lymphocytes, immunoblasts, eosinophils, plasma cells, histiocytes.
Angioimmunoblastic T-cell lymphoma: Expession of T-cell antigens.
Most of the other expected T-cell antigens are expressed, but loss of one or more is not uncommon.
Angioimmunoblastic T-cell lymphoma: Additional markers (4).
Positive: CD10, Bcl-6, CXCL13, PD-1.
This is the immunophenotype of follicular T-helper cells.
Angioimmunoblastic T-cell lymphoma: Association with EBV.
EBV is present in scattered immunoblasts in most cases.
Angioimmunoblastic T-cell lymphoma: PCR (2).
Monoclonal rearrangement of TCR-gamma.
Ten percent of cases: Concurrent monoclonal rearrangement of IGH.
Angioimmunoblastic T-cell lymphoma: Cytogenetics.
+3, +5, +X.
Angioimmunoblastic T-cell lymphoma vs. peripheral T-cell lymphoma, NOS (4).
- Tumor cells in the germinal centers or the mantle zones.
- No enlarged FDC meshworks.
- No large high-endothelial vessels.
- Presentation is usually in an early stage.
Anaplastic large-cell lymphoma: Epidemiology (2).
ALK-positive: Second and third decades, mostly males.
ALK-negative: Middle-aged and elderly, no predilection for gender.
Anaplastic large-cell lymphoma: Typical presentation.
Lymphadenopathy, extranodal disease, systemic symptoms.
Anaplastic large-cell lymphoma: Prognosis.
Better in ALK-positive tumors.
Anaplastic large-cell lymphoma: Location of infiltrate.
Anaplastic large-cell lymphoma: Cytology.
Tumor cells are large and have eccentric reniform nuclei.
"Hallmark" cells have doughnut-shaped or wreath-like nuclei.
Anaplastic large-cell lymphoma: Histologic variants (3).
Common: Pleomorphic large cells with "hallmark" nuclei.
Lymphohistiocytic: Many admixed histiocytes.
Small-cell: Most small- to medium-sized tumor cells.
Anaplastic large-cell lymphoma: Expressed antigens (8).
Usually: CD45, EMA, Bcl-6, clusterin; TIA1, granzyme B, perforin.
Anaplastic large-cell lymphoma: Usually unexpressed antigens (2).
Anaplastic large-cell lymphoma: Expression of T-cell markers.
CD2, CD5, and/or CD4 is usually expressed.
Anaplastic large-cell lymphoma: "Null-cell" type.
T-cell lineage is apparent only at the genetic level.
Anaplastic large-cell lymphoma: Pattern of staining for ALK.
May be nuclear, cytoplasmic, or membranous, depending on the translocation.
Anaplastic large-cell lymphoma: Aberrant expression of antigens.
Some tumors express myeloid antigens.
Anaplastic large-cell lymphoma: Association with EBV.
Anaplastic large-cell lymphoma: Cytogenetics.
t(2;5)(p23;q35): 80% of tumors.
Anaplastic large-cell lymphoma: Examples of DLBCL that can mimic it (2).
ALK-positive, EMA-positive DLBCL . . .
- Positive: CD138, cIg.
- Negative: CD30, T-cell antigens.
CD30-positive DLBCL that resembles ALCL morphologically:
- Positive: B-cell antigens.
- Negative: T-cell antigens.
Anaplastic large-cell lymphoma vs. peripheral T-cell lymphoma, NOS (2).
- Better retention of T-cell antigens.
- Usually no expression of EMA.