3.5a WBC Pathology I Flashcards
Lymphoid tissue consists of? (3)
- Thymus
- Spleen
- LNs
What are the (2) divisions of the Hematopoietic System?
- Myeloid Tissue
2. Lymphoid Tissue
Myeloid tissue includes? (2)
BM and the cells derived from it (red cells, platelets, granulocytes, monocytes)
Myelogenous series (6)
- Myeloblast
- Promyelocyte
- Myelocyte
- Metamyelocyte
- Intermediate cell
- Mature cell
How is Promyelocyte differentiated from Myeloblast?
Presence of primary granules in promyelocyte
Of the myelogenous series:
- Youngest
- Scanty cytoplasm
- Nucleolus
Myeloblast
Of the myelogenous series:
- First in series
- Specific granules: basophil, eosinophil, neutrophil
- Nucleus occupies 60% of total cell size
Myelocyte
Of the myelogenous series:
- Sunset-like
- Indented nucleus
Metamyelocyte
- It is a stab/band cell
2. First to appear in PBS (counterpart of reticulocyte)
Intermediate cell
Of the myelogenous series: has filaments separating nuclei?
Mature cell
Refers to the decrease of WBC usually resulting from reduced numbers of NEUTROPHILS
Leukopenia
How is leukopenia similar to anemia?
Same cause: ineffective granulopoiesis (abnormal BM cannot produce WBC)
It refers to a clinically significant reduction in neutrophils
Agranulocytosis
What causes ineffective/inadequate granulocytosis? (4)
- Suppression of hematopietic stem cells
- Suppression of committed granulocyte precursors
- Ineffective maturion
- Congenital conditions
The ff describes which Ineffective/inadequate granulocytosis?
- Aplastic anemia (decrease in RBC, WBC, platelets)
- Granulocytopenia (accompanied by anemia, thrombocytopenia)
Suppression of hematopoietic stem cells
What types of drugs suppress committed granulocytic precursors? (4)
- Alkylating agents
- Antimetabolites
- Chloramphenicol
- Sulfonamides
What causes infective maturation?
Vitamin B12 deficiency –> decreased WBC
What diseases exemplify infective maturation wherein defective precursors die in the marrow? (2)
Hint: Vit. B12 deficiency
- Megaloblastic anemia
2. Myelodysplastic syndrome
An example of an inherited defect in specific genes that impair granulocytic deifferentiation
Kostmann Syndrome - severe chronic neutropenia (manifests as infection with bacteria)
Pathogenesis of Leukopenia (2)
- Suppression of hematopoietic stem cells
2. Increased destruction/accelerated removal of neutrophils
What causes increased destruction/accelerated removal of neutrophils? (3)
- Ig-mediated injury
- Autoantibodies against WBC
- Exposure to drugs - Increased peripheral utiliation
- Massive infection (anergy) - Splenic sequestration (splenomegaly)
- Excessive destruction secondary to enlargement of the spleen
What are the (2) main sources of WBC?
- Bone Marrow
2. Lymph Nodes
What are the (2) proliferative states?
- Reactive: benign proliferation
- BM: Leukocytosis
- LN: Lymphadenitis - Neoplastic: malignant
- BM: Leukemia
- LN: Lymphoma
(2) Reactive proliferation of WBC in BM
- Leukocytosis
2. Leukemoid Reaction
What happens in REACTIVE proliferation of WBC in BM?
Blood proliferates as a result of infection –> spills into peripheral blood
Which reactive process is being described?
- (+) increase in number of white cells in blood
- A common reaction to a variety of INFLAMMATORY states
- It’s focused on the infecting organism
- It could be any of the ff:
- neutrophilia
- lymphocytosis
- eosinophilia
- monocytosis
Leukocytosis
Which leukocytosis is
- seen in bacterial infections (pyogenic bacteria)
- tissue necrosis –> sterile inflammation
Neutrophilia
- Which leukocytosis is seen in chronic, viral, immunologic infections?
- Bordatella pertusis infection
Lymphocytosis
Which leukocytosis is seen in asthma, allergy, parasitic infections?
Eosinophilia
Which leukocytosis is seen in chronic infection, collagen disorder (SLE)?
Monocytosis
Which reactive process is being described?
- (+) high levels of WBC –> stimulation of myelogenous leukemia (reactive only, not leukemic)
- Benign proliferation of WBC in reaction to an overwhelming infection but DOES NOT constitute leukemia
- You do NOT see BLASTS in PBS
Leukemoid reaction
What PBS changes are seen in reactive proliferation? (2)
- Aggravation in the primary granules found in neutrophils
2. Reactive/Atypical lymphocytes
What morphologic changes can be seen in neutrophils during reactive proliferation in the BM? (4)
- Toxic granules
- elaboration/enlargement of ribosomes or endoplastic reticulum
- coarser and darker than the normal neutrophilic granules
- represent abnormal primary/azurophilic granules - Dohle bodies
- patches of dilated ER - Cytoplasmic vacuoles
- Shift to the left
- younger forms of WBC (stabs, myelocytes) are seen (NEVER BLASTS! they indicate neoplastic proliferation)
Which PBS change in reactive proliferation is being described?
- Large lymphocytes without granules (normal N:C ratio)
- (-) Dohle bodies and toxic granules
- Abundant and amoeboid cytoplasm –> RBCs tend to press on its borders (reaction to a virus)
Atypical lymhpocyte
What feature do atypical lymphocytes possess that distinguishes them from blasts?
N:C ratio. Blasts have scanty cytoplasm
Reactive proliferation of WBC in LNs (2)
- Acute lymphadenitis
2. Chronic lymphadenitis
Which process of reactive proliferation in LNs is being described?
- A reactive change secondary to MICROBIOLOGIC AGENTS and their toxins
- Drain foreign bodies, cell debris, bacterial products
- Affects cervical regions (d/t microbial drainage of teeth, tonsils), and axillary and inguinal regions (d/t infection of extremities)
- Nodes involved are PAINFUL and ENLARGED
Acute lymphadenitis
Which process of reactive proliferation in LNs is being described?
- LNs: NOT usually painful, NON-TENDER (nodal enlargement occurs over time)
- Related to VIRAL conditions
- Has three patterns
Chronic lymphadenitis
What are the (3) patterns of chronic lymphadenitits?
- Follicular hyperplasia
- Parafollicular/Paracortical Hyperplasia
- Sinus Histiocytosis
Which pattern of chronic lymphadenitis is being described?
- Refers to B-cell stimulation (humoral immune response)
- Defined by the presence of large oblong GERMINAL CENTERS (secondary follicles), surrounded by a collar of small resting naive B cells (mantle zone)
Follicular hyperplasia
What are the (2) regions of germinal centers?
- Centroblasts: dark zone
2. Centrocytes: light zone
The ff are examples of which patterns of chronic lymphadenitis?
- Toxoplasmosis
- HIV
- RA
Follicular hyperplasia
The ff are examples of which patterns of chronic lymphadenitis?
- Drugs
- IM
- Vaccines
Parafollicular hyperplasia
Which pattern of chronic lymphadenitis is being described?
1. Refers to T-cell stimulation
Parafollicular hyperplasia
In parafollicular hyperplasia, T-cells contain activated t-cells which are 3-4 times the size of resting lymphocytes that have round nuclei, open chromatin, several prominent nucleoli, and moderate amounts of pale cytoplasm. What do you call these cells?
Immunoblasts
Which pattern of chornic lymphadenitis is being described?
- Increase in the number and size of cells that line lymphatic sinusoids
- Lining lymphatic endothelial cells are hypertrophied
- Macrophages are increased in number
–>expansion and distention of sinuses
Sinus histiocytosis
What cells stimulate histiocytes and macrophages?
TH1 cells
Macrophages eat upB-cells that fail to produce Ab. These are seen in germinal centers as?
Tingle bodies - they kill bacteria
What are the broad categories of neoplastic proliferative states acc to cell origin? (4)
- Lymphoid neoplasm
- Plasma cell dyscrasias
- Myeloid neoplasms
- Histiocytoses
- All that come from myeloid stem cells
2. Only in BM
Myelogenous leukemia
Tumors of B-cell, T-cell, NK cell origin
Lymphoid neoplasm
Sources lymphoid neoplasm (2).
- BM: leukemia
2. LN: lymphoma
Which category of neoplastic proliferative states is being described?
- Predominantly in BM
- Leukemic type of manifestations ONLY
- Arise from hematopoietic progenitors
Myeloid neoplasm
(3) categories of Myeloid neoplasms
- Acute Myelogenous Leukemia (AML)
- Myelodysplastic Syndrome
- Chronic Myeloproliferative Disorder
Which category of myeloid neoplasm is being described?
1. immature proliferative cells accumulate in the BM
AML
Which category of myeloid neoplasm is being described?
1. Associated with infective hematopoiesis –> peripheral blood cytopenias
Myelodysplastic syndrome
Which category of myeloid neoplasm is being described?
1. Increased production of one or more terminally differentiated myeloid elements –> elevated peripheral blood count
Chronic myeloproliferative disorder
Which neoplastic proliferative state is being described?
1. Uncommon proliferative lesion of macrophages and dendritic cells
Histiocytoses
A special type of immature dendritic cell that gives rise to a spectrum of neoplastic disorders referred to as the Langerhans cell histiocytoses
Langerhans cell
What are the general classifications of lymphoid neoplasms? (2)
- Lymphoma (arises from nodal tissue)
2. Lymphocytic Leukemia (arises from BM)
Classification of Lymphoid Tumors (5)
- Precursor B-cell (pre-B cell): B-ALL (Acute Lymphoblastic)
- Precursor T-cell (pre-T cell): T-ALL
- Peripheral B cell
- Peripheral T cell or NK cell
- Hodgkins Lymphoma
Leukocyte Common Antigen (LCA)
CD45
Cell antigen in WBC: T-cell (4)
hint: lower numbers
CD1
CD5
CD4/8
CD3
Cell antigen in WBC: B-cell (5)
hint: higher numbers
CD10 (germinal center B)
CD19, CD20 (pre B, mature B)
CD23 (mature B)
IgM (plasma cell)
Cell antigens in WBC: Monocyte/macrophage (2)
CD14
CD64
Cell antigen in WBC: Stem cell (1)
CD34
Cell antigen in WBC: Hodgkin (2)
CD15
CD30
The diagnosis of lymphoma depends on which markers? (5)
- CD45 - LCA; differentiates carcinomas from lymphomas
- CD15, CD30 - Hodgkin
- CD19 - Pan-B marker, all B cells
- CD3 - peripheral T cell marker
- CD1,2,5,7 - precursor T cell markers
General characteristics of Lymphoid tumors (5)
- Monoclonal population
- Mostly B cells
- Each type has its own clinical presentation
- Associated with immune abnormalities
- Recapitulation of behavior normal counterparts
Symptoms of lymphoid tumors (3)
- Lymphadenopathy: multiple, painless, large, coalescent (otherwise, it’s lymphadenitis)
- Nonspecific symptoms: fever, malaise, weight loss
- Extranodal involvement
Main symptom of lymphoma
Lymphadenopathy
- The main ideologic identification of PRECURSOR tumors
2. Tells you that the tumor is very young
(+) TdT (Terminal Deoxynucleotidyl Transferase)
The ff describes which lymphoma/leukemia?
- Originates from thymus
- Adolescent males
- Rapidly enlarging symptomatic mass: mediastinal (thymic) mass
- (+) lymphadenopathy, (+) splenomegaly
- Aggressive
Acute Lymphoblastic Lymphoma/Leukemia (pre-T)
Peripheral B-cell Neoplasms (7)
- Small lymphocytic lymphoma (SLL)
- Chronic lymphocytic lymphoma (CLL)
- Follicular lymphoma
- Diffuse large B-cell lymphoma (DLBCL)
- Burkitt lymphoma
- Mantle cell lymphoma
- Marginal Cell Lymphoma/Maltoma
Which peripheral B-cell Neoplasm:
- Elderly, >60, male
- Asymptomatic/nonspecific/mild
- BM involvement
- Can spill into blood: LN –> BM –> blood (CLL-like picture)
- Indolent
- Transformation to large B-cell lymphoma –> Richter syndrom
- Transformation to prolymphocyte
Small Lymphocytic Lymphoma (SLL)
Chromosomal abnormality in SLL
Trisomy 12
Immunophenotype of B and T markers of SLL
- B markers: CD19, 20, 23
2. T markers: CD5
Which (2) B-cell tumors have a T-cell marker (CD5)?
SLL
Mantle Cell Lymphoma
The ff microscopic features describe which Peripheral B-cell Neoplasm?
- Diffuse effacement of nodal architecture
- No more follicles
- (+) uniform round cells with prominent nucleoli
- (+) prolymphocytes
SLL
The ff describe which peripheral B-cell neoplasm?
- Abnormal B cell in blood
- Increased WBC count (decreased WBC in SLL)
- Its chromosomal abnormality, age, sex, distribution, clinical picture is the same as SLL
Chronic Lymphocytic Lymphoma (CLL)
Diagnosis of CLL
Absolute Lymphocyte count: >4000/cumm
The most common leukemia of adults
CLL
The ff are PBS features of which peripheral B-cell neoplasm?
- > 4-5 lymphocytes/OIO (normal: 1-3)
- 100% lymphocytes (normal: 20-40%)
- Smudge cell
CLL
What characteristic feature is seen in the PBS of CLL?
Smudge Cell
Lab used for diagnosis of SLL
Biopsy of LN
Lab used for diagnosis of CLL
PBS
Which peripheral B-cell neoplasm is being described?
- M=F, middle age
- Symptoms: generalized, painless lymphadenopathy with BM involvement
- Genetic abnormality: t(14:18) BCL-2 protooncogene
- Characteristically devoid of apoptotic cells (because of BLC2, which antagonizes apoptosis)
- Indolent, incurable
- Progress to Diffuse DLBL if with c-MYC
Follicular lymphoma
Hallmark of follicular lymphoma
t(14:18)
The ff are immunophenotypes of?
CD10, 19, 20
BCL-2 protein
Follicular lymphoma
Morphological characteristics describe?
- Well-defined germinal center
- Follicles confined to the cortex
- Presence of inactive B collar
Normal LN
The ff are microscopic characteristics of?
- (+) nodular aggregates throughout LN
- Mixture of centroblasts and centrocytes
Follicular lymphoma
The ff gross features seen in the spleen describe?
1. Pulp follicles expanded by follicular lymphoma cells (prominent nodules)
Follicular lymphoma
What is present in follicular lymphoma that is absent in a reactive follicle?
BCL-2
Rapidly enlarging symptomatic mass at a single nodal or extranodal site - symptom of?
Nodal: Waldeyer Ring
Extranodal: GIT, skin, bones, brain
Diffuse Large B-cell Lymphoma (DLBCL)
Cytogenetics of DLBCL (2)
- BCL-6
Dysregulation –> undifferentiated proliferative state
Has anti-p53 activity to prevent activation of DNA repair mechanism - t(14:18)
Leads to overexpresion of BCL-2, which is anti-apoptotic
Immunophenotype of?
CD19, 20, +/- CD10
DLBCL
Microscopic features of?
- Large cells (compared with endothelium of the blood vessel)
- Diffuse
- No follicles
- Invades adipose tissue
- Large nuclei, diffuse chromatin, prominent nucleoli
DLBCL
Grossly, what usually produces multifocal expansion of white pulp? indolent or aggressive B-cell lymphoma?
indolent
What is the histology of Burkitt’s lymphoma?
Starry sky appearance: monotonous sea of round cells interspersed with macrophages
The ff are characteristics of?
- Children and young adults
- Prognosis: very agressive
- Symptoms: (african/endemic) facial, pelvic. (sporadic/nonendemic) abdominal (ileocecal, peritoneum)
- Pathogenesis: t(8,14) of c-MYC gene, EBV
- Immunophenotype: CD10, 19, 20; BCL-6; IgM
Burkitt Lymphoma
(2) types of Burkitt Lymphoma
- Endemic
2. Sporadic
Which type of Burkitt lymphoma:
- Presents as a mass involving the mandible
- Predilection to abdominal viscera: kindeys, ovaries, adrenals
Endemic Burkitt Lymphoma
Which type of Burkitt Lymphoma?
1. Presents as a mass involving ileocecum and peritoneum
Sporadic Burkitt Lymphoma
Which peripheral B-cell neoplasm?
- 50-60 years old, male
- Presents as generalized painless lymphadenopathy + extranodal spread (BM, spleen, liver, GIT [lymphomatoid polyps])
- Immunophenotye: -CD23
- Genetic abnormality: t(11:14) increased expression of cyclin D1
- Prognosis: very poor, not curable
Mantle Cell Lymphoma
Microscopic features of?
- (LPO) lymphoid cells surround a small, atrophic germinal center –> mantle zone pattern of growth
- (HPO) homogenous population of small lymphoid cells with irregular nuclear outlines, condensed chromatin, scant cytoplasm
Mantle Cell Lymphoma
- Tumors of Mucosa Associated Lymphoid Tissue (thus it’s aka MALToma)
- Erogenous group of Bcell that arise within LN, spleen, extranodal tissues
- Evidence of somatic hypermutation of memory Bcell origin
- Good prognosis
- Chromosomal Abnormality: t(11:18) or t(14:18)
Marginal Cell Lymphoma/Maltomas
Characteristics of?
- Arise from chronic inflammatory disorders
- Remain localized for prolonged periods
- Regress if inciting agent is eradicated
Marginal Cell Lymphoma/Maltoma
Peripheral T-cell Neoplasms (5)
- Mycosis Fungoides/Sezary Syndrome
- Extranodal NK/T-cell lymphoma
- Adult T-cell lymphoma/Leukemia (CD4)
- Anaplastic Large Cell Lymphoma (CD8)
- Large Granular T-cell Lymphocytic Leukemia
T-cell Lymphoma of the skin (2)
- Mycosis Fungoides
2. Sezary Syndrome
Infiltration of the skin by neoplastic CD4 T-cells
Mycosis Fungoides
Clinical stages in Mycosis Fungoides (3)
- Inflammatory/Premycotic Phase: Flat lesion
- Plaque Phase: Elevation of lesion
- Tumor Phase: Mass formation (absent in Sezary Syndrome)
Histologic characteristics of?
- Epidermis and upper dermis are infiltrated by neoplastic T-cells
- Cerebriform appearance (d/t infolding of nuclear membrane)
- Extracutaneous spread (most commonly to LN, BM) - characterizes late disease progression
Mycosis Fungoides
Generalized exfoliative erythroderma
Sezary Syndrome
How does Sezary Syndrome differ from Mycosis Fungoides? (2)
- (-) Tumor
2. (+) Associated leukemia of sezary cells with characteristic cerebriform nuclei
- Lethal midline granuloma
2. Midline malignant reticulosis
Extranodal NK/T-cell Lymphoma
The ff are symptoms of?
- Destructive masses of sinuses
- Nasopharynx
- Involves CENTRAL portion of FACE (destructive nasopharyngeal mass)
Extranodal NK/T-cell Lymphoma
Morphology of Extranodal NK/T-cell Lymphoma
Small and large lymphocytes invading small BV –> necrosis
Extranodal NK/T-cell Lymphoma is associated with which virus?
EBV
Characteristics of?
- Biopsy: (-) malignancy due to extensive ischemic necrosis
- Highly aggressive: responds to radiation therapy, not chemotherapy
- Poor prognosis with advanced disease
Extranodal NK/T-cell Lymphoma
- CD4 Tcell proliferation
- DIRECTLY caused by Human T-cell Leukemia Retrovirus type 1 (HTLV-1)
- Highly aggressive, poor prognosis
Adult T-cell Lymphoma
It is the ONLY lymphoma associated with a virus. Name the virus.
Adult T-cell Lymphoma: HTLV-1
Symptoms of?
- Skin lesions: flat, thick areas
- Hypercalcemia
- General Lymphadenopathy
- Enlarged liver, spleen
- BM with peripheral blood lymphocytosis
Adult T-cell Lymphoma
Morphology of?
1. CLOVER LEAF/FLOWER CELLS: multilobed nuclei
Adult T-cell Lymphoma
Complications of Adult T-cell Lymphoma (1)
Demyelinating disorder of brain and spinal cord
Virus that encodes Tax protein, which enhances lymphocyte growth and survival
HTLV-1
Characteristics of Hodgkins Lymphoma (opposite is true of Non-Hodgkins Lympoma) (4)
- Localized to a single axial group of nodes: cervical, mediastinal, para-aortic
- Contiguous spread
- Rarely involves Waldeyer’s Ring and mesenteric nodes
- Rare extranodal presentation
Lymphoid neoplasms derived from B-cells forming neoplastic giant cells (RS cells) that induce accumulation of other inflammatory cells
Hodgkin Lymphoma
The first human cancer to be successfully treated with radiation therapy and chemotherapy
Hodgkin Lymphoma
Characteristics of?
- (+) RS cells
- Polymorphic cell
- Involves a single axial LN chain
- Spread is contiguous and stereotyped: cannot jump from site to site, LN -> spleen -> liver -> BM -> other tissues
- Rare extranodal presentation
Hodgkin Lymphoma
Molecular pathogenesis of Hodgkin Lymphoma
Activation of NF-KB (transcription factor) by EBV
In Hodgkin Lymphoma, this determines the course, choice of therapy, and prognosis of the disease
Ann Arbor Classification
WHO classification of Hodgkin Lymphoma (5)
- Nodular sclerosis
- Mixed cellularity
- Lymphocyte-rich
- Lymphocyte depletion
- Lymphocyte predominance
Which WHO classification of Hodgkin Lymphoma?
HISTO
-Bands of collagen
-Lacunar cells
CLINICAL FEATURE
- M=F, young adults
- Common in mediastinal and cervical regions
- EBV-
Nodular sclerosis
Which WHO classification of Hodgkin Lymphoma?
HISTO
-Many different cells, many RS
CLINICAL FEATURE
- M>F
- EBV+
- Lymphadenopathy
- Biphasic age incidence
Mixed cellularity
Which WHO classification of Hodgkin Lymphoma?
HISTO
-Few lymphocyte
-Many RS and variants
CLINICAL FEATURES
- Elderly, males
- HIV+
- Most EBV+
Lymphocyte depletion
Which WHO classification of Hodgkin Lymphoma?
HISTO
-Many lymphocytes and RS
CLINICAL FEATURES
- Middle age, males
- Enlarged LNs
- EBV+
Lymphocyte-rich
Which WHO classification of Hodgkin Lymphoma?
HISTO
-Few RS/LH variant (popcorn cell)
-(-) CD15 and 30
CLINICAL FEATURES
- Young males
- EBV-
- Cervical/axillary lymphadenopathy
Lymphocyte predominance
Cells that release factors that induce accumulation of reactive lymphocytes, macrophages, granulocytes
RS cells
All classifications of Hodgkin Lymphoma are affected by EBV except? (2)
- Nodular sclerosis
2. Lymphocytic predominance
In nodular sclerosis and lymphocytic predominance, what cells are seen instead of RS cells?
NS: Lacunar cells
LP: Popcorn cells
All WHO classifications of Hodgkin Lymphoma will be CD15+ and CD30+ except?
Lymphocytic predominance
Which type of Hodgkin Lymphoma?
- Most common form of HL
- Characterized by the presence of LACUNAR CELLS and the DEPOSITION of COLLAGEN in bands that divide LNs into circumscribed nodules
Nodular Sclerosis
RS cells (3)
PAX5+
CD15+
CD30+
Which type of Hodgkin Lymphoma?
- Involved LNs are diffusely effaced by a heterogenous cellular infiltrate (eosinophils, T-cells)
- Plasma cells + benign macrophages + RS cells
Mixed cellularity
Which type of Hodgkin Lymphoma?
- Uncommon form of classical HL: reactive lymphocytes make up the majority of the infiltrate
- Involved LNs: diffusely effaced, vague nodularity
Lymphocyte-rich
Which type of Hodgkin Lymphoma?
- Least common form of HL
- Characterized by a paucity of lymphocytes and a relative abundance or RS cells or their pleomorphic variants
Lymphocyte depletion
Which type of Hodgkin Lymphoma?
- Uncommon, non-classical variant of HL
- Involved nodes: effaced by a nodular infiltrate of small lymphocytes + macrophages
- Contains LH (lymphocytic and histiocytic) RS variants (popcorn cell)
Lymphocyte predominance