LN Flashcards
Function of LN
-Drain protein containing fluid that escapes from blood capillaries.
-Transport fats from GI tract to the blood
Produce lymphocytes
-Develop immunity
Lymph flows into LN through the?
Afferent vessels
Lymph flows out of LN through?
Efferent Vessels
What are small bean shaped structures lying along the course of lymphatics?
Lymph Nodes
Where can the primary LN follicle be found?
Germinal Center
What are the 3 components that makes up the node?
-lymphatic sinuses
-blood vessels
-parenchyma
What is the thin capsule around node made up of?
Fibroblast & collagen
Space under capsule is called?
Subcapsular sinuses
Should a LN have epithelium? If so, explain what it’s presence means
No, if it is present then sus mets ca
—- is known as the T cell house
Paracortex
Where are plasma cells & macrophages plentiful?
Medulla
Primary & secondary follicles are found here
Cortex
B cells enter the LN through?
High Endothelial Venules (HEVs)
Activated B cells within lymphoid follicles are known as?
Follicular Center Cells
B cells that have cleaved nuclei are called?
Centrocytes
Non-cleaved cells with larger more open nuclei & several nucleoli?
Centroblasts
Stimulated mature B cells responding to an antigen change into — & then —- which then leave follicle & pass to —- & —-
Centroblasts, centrocytes, paracortex, medullary sinuses
After leaving follicles, B cells become —- which divide to give rise to plasma cells or memory B cells.
Immunoblasts
Where does B cell maturation occur?
Germinal Center
B cells undergo their development in —- while T cells in the —-
Bone marrow, Thymus
If something went wrong during phase at bone marrow – abnormal cells are being made there (primary lymphoid organ), it results in —-?
Leukemia
If there is something that goes wrong in secondary lymphoid organ —?
Lymphoma
What cells are numerous in paracortex & acts as APCs?
Dendritic Cells
Paracortical T-cells, mostly —- are key players in the recognition of antigen.
CD4(+) T-helper cells
The B-cells that survive the tumultuous, Darwinian struggle within the germinal center eventually differentiate into —-
Plasma Cells
What cells can be found in cortex?
B Cells
Macrophages
Follicular Dendritic Cells**
Paracortex has what kind of cells present?
T Cells
Immunoblasts
Langerhans’s Cells
Plasma cells
Immunoblasts
Plasmacytoid Lymphocytes
Rare macrophages
can be found where?
Medulla
Resting or mature
65-90% of cell population
Round nucleus (generally)
Smooth membrane
Hyperchromatic, coarse, even chromatin
Thin rim of cytoplasm
Nucleoli- absent to inconspicuous
Small Lyc
10 to 12 microns in size
Round with a cleaved membrane
Thin rim of cytoplasm
Absent to inconspicuous nucleoli
small cleaved centrocytes
20 to 40 microns
Cleaved angulated nuclei
Coarse chromatin, even distribution
Inconspicuous nucleoli
Large Cleaved Lyc
First sign of antigenic stimulation
20 to 40 microns
Round vesicular nuclei
1-3 prominent peripheral nucleoli
Moderate, basophilic cytoplasm
Small/large centroblast
Before B cells become plasma cells, they are —?
Immunoblasts
Large nuclei
Prominent central macronucleolus or:
2 or more nucleoli (T Type)
Plasmacytoid cytoplasm
Irregular membrane
Occasional plasmacytoid cytoplasm and perinuclear
Immunoblasts (B or T cell)
Specialized histiocytes
Antigen presenting
Stromal
Long Cytoplasmic processes
Non phagocytic
Part of reticular network of lymph node
Follicular Dendritic Cells
Contain bits of B-cells (failure to bind antibody to antigen)
Seen mostly in benign conditions**
CAN be seen in aggressive (high grade) lymphomas
Tingible Body Macrophages (TBM)
Represent reticulum cells in follicles & germinal centers.
In aspirates, these form large structures that can be in flat, loose sheets or cohesive 3-D cell clusters.
Cytoplasm is abundant, pale, ill-defined and delicate
Lympho-histiocytic Aggregate in LN FNA
Enlarged nodes(<3 cm in diameter), usually NOT tender
Common in the inguinal, axillary, and cervical regions because these lymph nodes drain large areas
The FNA is quite cellular
MOST COMMON DIAGNOSIS IN FNA
CHR Lymphadenitis (Rx LN)
Polymorphous
Small lymphoid cells
May see plasma cells and immunoblasts
Tingible body macrophages
- High range of maturation
- Lymphohistiocytic aggregates
Key: POLYMORPHOUS
Rx LN
What is the dx for:
Polymorphic population,
Morphologic Diversity
Lymphoglandular bodies in the bkg
Rx LN
These aggregates create the appearance of an epithelioid group of cells.
Lymphoid Tangles in LN FNA
Lymphoid globules or hyaline bodies that are detached blebs of lymphocyte cytoplasm
Lymphoglandular Bodies
Cat Scratch is caused by — and can be stained with —?
Bartonella hensalae, silver stain
Lump that develops at the collar bone
Branchial Cleft Cyst
Freely movable beneath the skin
Tender
Less firm
Arising and subsiding over weeks or months
PAIN
Rx Adenopathy
Matted
Non-tender
Stony hard if fibrosis is present
Slowly, inexorably growing
Malignant Adenopathy
—– are clonal, uncontrollably expanding, destructive proliferations of lymphoid cells.
Lymphoma
Lymphoid neoplasms that predominantly involve the bone marrow and peripheral blood are considered
Leukemia
CD34, TdT, CD117
Markers for Immature Cells
CD3, CD5, CD4, CD8, CD7
T cell Markers
CD19, CD20, CD79a, PAX-5
B cell markers
CD38, CD138, CD79a
Plasma Cell markers
Dx for a mixed population of small lyc + large cells
Rx Node, Follicular Lymphoma
Dx of small cell pattern of lyc
SLL/CLL, Mantle Cell Lymphoma
What cells have large bright red nucleolus surrounded by clear zone & what condition are the found in?
Reed Sternberg Cells, Hodgkin’s Lymphoma
Much less common than classical type incidence
Usually, males between 30-50
Malignant cells are monoclonal B cells: L & H cells, large cells w/ one large multilobate, folded nucleus. Their contorted nuclear shape gives the name “popcorn cells”
Smaller than typical RS cells w/ smaller nucleoli
(-) for CD30, CD15
(+) for CD20 & CD45 and 50% show + EMA
Nodular Lymphocyte predominant HL
Reed Sternberg stains (+) for which markers but doesn’t stain the lyc in the bkg
CD15 & CD30
What dx is:
-Seen mostly in young adult male
Abundant cellularity:
-RS cells
- Hodgkin’s cells
-Lymphs
-Eosinophils
-Plasma cells
-Macrophages
HL; mixed cellularity
Seen in more young females
Fibrous tissue (fibroblasts)
Few RS & Hodgkin’s cells
Few Lymphs
Popcorn cells
May be confused w/ granulomatous lymphadentitis
=> Nodular bands of tissue are filled w/ fibroblasts – hard lymph nodes
HL - Nodular Sclerosing Type
Lymph flows into LN through —- vessels & out through —-
narrow, wider
Most of the fluid collects in main channel for lymphatic drainage called —?
Thoracic duct
2 very important streams for lymphatic flow; contributes about 40% of fluid that gets into thoracic duct
Liver & intestine
T cells either release —- to kill invaders or activate the —– to do the killing
cytokines, APCs (macrophages)
Maturity of B cells:
Centroblasts => centrocyte => Immunoblasts (paracortex & medullary sinus) => plasma cells
Paracortical T-cells, mostly ——- cells, are key players in the recognition of antigen.
CD4(+) T-helper
—— have larger and more empty-appearing nuclei, the germinal centers show up as pale disks in the cortex on H&E stained slides.
Activated B-cells
They are thought to represent the reticulum cells in follicles and germinal centers.
Lympho-histiocytic aggregate
It is characterized by a t(11;14) translocation involving the cyclin D1 gene (cell cycle).
Mantle Cell Lymphoma
Immunophenotype (CD10+), cytogenetic (t(14;18)), and constitutively over-express the Bcl-2 gene (B-Cell Lymphoma ) that blocks apoptosis.
40% progress to Diffuse Large B-Cell Lymphoma (TP53 gene mutation)
-½ can transform into large B cell lymphoma
Follicular Lymphoma
Activates c-myc oncogene
Has an endemic form found in Africa (EBV); sporadic form found in US (both in children)
CD19, CD20 positive, CD10 also may be positive
Characteristics t(8:14) translocation
Burkitt’s Lymphoma
— stains the Epstein’s Barr Body in — lymphoma
EBER, Burkitt’s Lymphoma
