LYMPHOID TISSUE INFLAMMATION Flashcards
1
Q
What is the normal white blood cell (WBC) count?
A
5-10 K/μL.
2
Q
What is leukopenia?
A
A low WBC count (<5 K/μL).
3
Q
What is leukocytosis?
A
A high WBC count (>10 K/μL).
4
Q
What are the main causes of neutropenia?
A
Drug toxicity (e.g., chemotherapy) and severe infection (e.g., gram-negative sepsis).
5
Q
What pharmacological agents can boost granulocyte production?
A
GM-CSF or G-CSF.
6
Q
What are the main causes of lymphopenia?
A
Immunodeficiency (e.g., HIV, DiGeorge syndrome), high cortisol state, autoimmune destruction, and whole-body radiation.
7
Q
What is neutrophilic leukocytosis
A
and what causes it?
8
Q
What is monocytosis
A
and what causes it?
9
Q
What is eosinophilia
A
and what causes it?
10
Q
What is basophilia
A
and when is it commonly seen?
11
Q
What are the causes of lymphocytic leukocytosis?
A
Viral infections (e.g., EBV) and Bordetella pertussis infection.
12
Q
What is infectious mononucleosis (IM)?
A
An EBV infection causing lymphocytic leukocytosis of reactive CD8+ T cells.
13
Q
How is EBV transmitted?
A
Via saliva (‘kissing disease’), typically affecting teenagers.
14
Q
What organs are primarily infected by EBV?
A
Oropharynx (pharyngitis), liver (hepatitis), and B cells.
15
Q
What causes splenomegaly in infectious mononucleosis?
A
T-cell hyperplasia in the periarterial lymphatic sheath (PALS) of the spleen.
16
Q
What test is used to screen for infectious mononucleosis?
A
The monospot test, detecting heterophile IgM antibodies.
17
Q
What does a negative monospot test suggest?
A
Cytomegalovirus (CMV) as a possible cause of infectious mononucleosis.
18
Q
What are the complications of infectious mononucleosis?
A
Splenic rupture, rash after ampicillin exposure, and increased risk of B-cell lymphoma during immunodeficiency.
19
Q
What are the primary lymphoid organs?
A
Bone marrow and thymus.
20
Q
What are the secondary lymphoid organs?
A
Lymph nodes, spleen, and mucosal-associated lymphoid tissues (MALT).
21
Q
What are the two broad categories of the immune system?
A
Innate and adaptive immune systems.
22
Q
What is leukopenia?
A
A condition marked by decreased circulating leukocytes, especially neutropenia.
23
Q
What is the most common cause of agranulocytosis?
A
Drugs, particularly cytotoxic agents.
24
Q
What is leukocytosis?
A
An increase in the number of WBCs in the peripheral blood.
25
What conditions can cause neutrophil leukocytosis?
Bacterial infections and tissue necrosis.
26
What is eosinophilia and its common causes?
Increased circulating eosinophils due to allergies, parasitic infections, or drug reactions.
27
What causes basophilia?
Chronic myeloproliferative diseases.
28
What is lymphadenitis?
Inflammation of lymph nodes.
29
What are the classifications of chronic nonspecific lymphadenitis?
Follicular hyperplasia, paracortical hyperplasia, and sinus histiocytosis.
30
What is follicular hyperplasia?
Activation of the humoral immune system, commonly seen in HIV and rheumatoid arthritis.
31
What is paracortical hyperplasia?
Activation of the cellular immune system, seen in viral infections or post-immunization.
32
What is sinus histiocytosis?
An increase in the size and number of cells lining lymphatic sinusoids, often seen in lymph nodes draining cancer sites.
33
What is Hodgkin lymphoma characterized by?
Presence of Reed-Sternberg cells and orderly spread to contiguous lymph node chains.
34
What are the five subtypes of Hodgkin lymphoma?
Nodular sclerosis, mixed cellularity, lymphocyte-rich, lymphocyte depletion, and nodular lymphocyte predominance.
35
What is the most common subtype of Hodgkin lymphoma?
Nodular sclerosis.
36
What is the typical immunophenotype of classical Hodgkin lymphoma?
CD15+, CD30+, negative for CD45.
37
What is the characteristic cell in nodular lymphocyte predominance Hodgkin lymphoma?
Popcorn cells (L&H cells).
38
What are the clinical features of Hodgkin lymphoma?
Painless lymphadenopathy, B symptoms (fever, weight loss, night sweats), and immune dysregulation.
39
What are the key functions of lymphoid organs?
Protect against pathogens and optimize antigen recognition and lymphocyte activation.
40
What cells are derived from hematopoietic stem cells?
Lymphocytes, neutrophils, monocytes, eosinophils, basophils, and other blood cells.
41
What are the main types of lymphocytes?
T-cells (helper, cytotoxic, suppressor, memory) and B-cells (plasma cells, memory B cells).
42
What are the causes of neutropenia?
Drug toxicity, suppression of HSCs, ineffective hematopoiesis, and increased destruction/sequestration of neutrophils.
43
What is the morphology of bone marrow in neutropenia?
Can show hypercellularity (compensatory) or hypocellularity (depletion of precursors).
44
What are the clinical consequences of neutropenia?
Increased susceptibility to bacterial and fungal infections, ulcerating lesions, and life-threatening infections.
45
What cytokines maintain WBC homeostasis?
Cytokines like IL-1, TNF, and growth factors such as G-CSF and IL-5.
46
What is the pathogenesis of leukocytosis in infections?
Cytokines induce granulocyte release from the bone marrow and proliferation of precursors.
47
What is the difference between reactive and neoplastic leukocytosis?
Reactive leukocytosis is due to infections or inflammation, while neoplastic leukocytosis is due to malignancy.
48
What are the key features of chronic nonspecific lymphadenitis?
Follicular hyperplasia, paracortical hyperplasia, and sinus histiocytosis.
49
What are the causes of follicular hyperplasia in lymphadenitis?
HIV, rheumatoid arthritis, and toxoplasmosis.
50
What are the morphological features of paracortical hyperplasia?
Expansion of T-cell zones, immunoblasts, and hypertrophy of vascular endothelium.
51
What are the causes of sinus histiocytosis?
Commonly associated with lymph nodes draining cancer sites.
52
What distinguishes Hodgkin lymphoma from Non-Hodgkin lymphoma?
Hodgkin lymphoma spreads in an orderly fashion and features Reed-Sternberg cells, while NHL spreads unpredictably.
53
What genetic mutations are commonly seen in Hodgkin lymphoma?
NF-κB activation by EBV or mutations in regulators like IκB or A20.
54
What is the "starry sky" appearance in histology
and where is it seen?
55
What are the main subtypes of peripheral T-cell and NK-cell neoplasms?
Peripheral T-cell lymphoma, anaplastic large cell lymphoma, adult T-cell leukemia/lymphoma, and mycosis fungoides/Sezary syndrome.
56
What is the hallmark genetic mutation in anaplastic large cell lymphoma?
Rearrangement of the ALK gene on chromosome 2p23.
57
What are the clinical features of adult T-cell leukemia/lymphoma?
Lymphadenopathy, skin lesions, hepatosplenomegaly, hypercalcemia, and leukocytosis.
58
What are the three stages of mycosis fungoides?
Premycotic phase, plaque phase, and tumor phase.
59
What is Sezary syndrome?
A variant of mycosis fungoides characterized by erythroderma, leukemic Sezary cells, and lymphadenopathy.
60
What defines acute leukemia?
Neoplastic proliferation of blasts with >20% in the bone marrow.
61
What causes the acute presentation in leukemia?
Blast crowding of normal hematopoiesis causing anemia, thrombocytopenia, and neutropenia.
62
How do blasts typically appear in acute leukemia?
Large, immature cells with punched-out nucleoli.
63
What are the two major types of acute leukemia?
Acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML).
64
What marker characterizes lymphoblasts in ALL?
Positive nuclear staining for TdT, a DNA polymerase.
65
Which demographic is most affected by ALL?
Children, especially those with Down syndrome (after age 5).
66
What surface markers are expressed in B-ALL?
CD10, CD19, and CD20.
67
What cytogenetic abnormality in ALL has a good prognosis?
t(12;21), more common in children.
68
What cytogenetic abnormality in ALL has a poor prognosis?
t(9;22), also known as Philadelphia+ ALL, more common in adults.
69
What distinguishes T-ALL from B-ALL?
T-ALL lacks CD10 and presents as a mediastinal mass in teenagers.
70
What is the defining marker of myeloblasts in AML?
Positive cytoplasmic staining for myeloperoxidase (MPO).
71
What are Auer rods?
Crystal aggregates of MPO seen in myeloblasts.
72
What cytogenetic abnormality is associated with acute promyelocytic leukemia (APL)?
t(15;17), involving the retinoic acid receptor (RAR).
73
How is APL treated?
All-trans-retinoic acid (ATRA), which induces blast maturation.
74
What feature is characteristic of acute monocytic leukemia?
Infiltration of gums by monoblasts, which usually lack MPO.
75
What is acute megakaryoblastic leukemia associated with?
Down syndrome (before age 5) and a lack of MPO.
76
What is chronic leukemia?
Neoplastic proliferation of mature circulating lymphocytes.
77
What is the most common leukemia overall?
Chronic lymphocytic leukemia (CLL).
78
What markers are characteristic of CLL?
CD5 and CD20 co-expression on naïve B cells.
79
What are complications of CLL?
Hypogammaglobulinemia, autoimmune hemolytic anemia, and transformation to diffuse large B-cell lymphoma (Richter transformation).
80
What defines hairy cell leukemia?
Mature B cells with hairy cytoplasmic processes and positivity for TRAP.
81
What is the treatment for hairy cell leukemia?
2-CDA (cladribine), an adenosine deaminase inhibitor.
82
What is adult T-cell leukemia/lymphoma (ATLL) associated with?
HTLV-1 infection, seen in Japan and the Caribbean.
83
What are key features of ATLL?
Rash, lymphadenopathy, hepatosplenomegaly, and lytic bone lesions with hypercalcemia.
84
What is mycosis fungoides?
Neoplastic proliferation of CD4+ T cells infiltrating the skin, causing rashes, plaques, and nodules.
85
What is Sezary syndrome?
Blood involvement in mycosis fungoides, characterized by cerebriform nuclei (Sezary cells).
86
What are myeloproliferative disorders (MPDs)?
Neoplastic proliferation of mature myeloid cells, typically occurring in late adulthood.
87
What are common complications of MPDs?
Hyperuricemia, gout, marrow fibrosis, and transformation to acute leukemia.
88
What is chronic myeloid leukemia (CML)?
Neoplastic proliferation of mature myeloid cells, especially granulocytes and basophils.
89
What genetic mutation drives CML?
t(9;22) Philadelphia chromosome, forming the BCR-ABL fusion protein.
90
What is the first-line treatment for CML?
Imatinib, a tyrosine kinase inhibitor.
91
How is CML distinguished from a leukemoid reaction?
CML has negative LAP stain, increased basophils, and t(9;22).
92
What is polycythemia vera (PV)?
Neoplastic proliferation of mature myeloid cells, especially RBCs.
93
What are symptoms of PV caused by hyperviscosity?
Blurry vision, headache, thrombosis, plethora, and post-bathing pruritus.
94
What mutation is associated with PV?
JAK2 kinase mutation.
95
How is PV treated?
Phlebotomy; second-line therapy is hydroxyurea.
96
What distinguishes PV from reactive polycythemia?
PV has low EPO and normal SaO2, whereas reactive forms show increased EPO.
97
What is essential thrombocythemia (ET)?
Neoplastic proliferation of mature myeloid cells, especially platelets.
98
What symptoms are seen in ET?
Bleeding or thrombosis; no significant risk of hyperuricemia or gout.
99
What is myelofibrosis?
Neoplastic proliferation of megakaryocytes, leading to marrow fibrosis.
100
What causes marrow fibrosis in myelofibrosis?
Excess PDGF production by megakaryocytes.
101
What are clinical features of myelofibrosis?
Splenomegaly, tear-drop RBCs, nucleated RBCs, and immature granulocytes.
102
What is lymphadenopathy (LAD)?
Enlargement of lymph nodes.
103
What causes painful LAD?
Acute infections (acute lymphadenitis).
104
What causes painless LAD?
Chronic inflammation, metastatic carcinoma, or lymphoma.
105
What are the regions of hyperplasia in inflammatory LAD?
Follicular (B-cell), paracortex (T-cell), and sinus histiocytes.
106
What is follicular lymphoma?
Neoplastic proliferation of small B cells (CD20+) forming follicle-like nodules.
107
What translocation drives follicular lymphoma?
t(14;18), involving overexpression of Bcl2.
108
How is follicular lymphoma distinguished from reactive follicular hyperplasia?
Disruption of lymph node architecture, lack of tingible body macrophages, and monoclonality.
109
What is mantle cell lymphoma?
Neoplastic proliferation of small B cells expanding the mantle zone.
110
What translocation drives mantle cell lymphoma?
t(11;14), leading to cyclin D1 overexpression.
111
What is marginal zone lymphoma associated with?
Chronic inflammation, such as in Sjogren syndrome, Hashimoto thyroiditis, or H. pylori gastritis.
112
What is Burkitt lymphoma?
Neoplastic proliferation of intermediate-sized B cells (CD20+), associated with EBV.
113
What translocation drives Burkitt lymphoma?
t(8;14), involving c-myc oncogene overexpression.
114
What is the characteristic histological appearance of Burkitt lymphoma?
Starry-sky appearance due to high mitotic index and macrophages.
115
What is diffuse large B-cell lymphoma?
Aggressive neoplastic proliferation of large B cells (CD20+) growing diffusely in sheets.
116
What are Reed-Sternberg (RS) cells?
Large B cells with multilobed nuclei and prominent nucleoli, seen in Hodgkin lymphoma.
117
What markers characterize RS cells?
CD15+ and CD30+.
118
What is the most common subtype of Hodgkin lymphoma?
Nodular sclerosis, presenting with mediastinal or cervical lymphadenopathy.
119
What cytokine is associated with eosinophilia in mixed cellularity Hodgkin lymphoma?
IL-5.
120
What is multiple myeloma?
Malignant proliferation of plasma cells in the bone marrow.
121
What are common features of multiple myeloma?
Lytic bone lesions, hypercalcemia, M spike on SPEP, Rouleaux formation, and risk of infection.
122
What is Waldenstrom macroglobulinemia?
B-cell lymphoma with monoclonal IgM production, causing hyperviscosity symptoms.
123
What are Birbeck granules?
Tennis racket-shaped structures seen in Langerhans cell histiocytosis.
124
What are myeloproliferative disorders (MPDs)?
Neoplastic proliferation of mature myeloid cells, typically occurring in late adulthood.
125
What are common complications of MPDs?
Hyperuricemia, gout, marrow fibrosis, and transformation to acute leukemia.
126
What is chronic myeloid leukemia (CML)?
Neoplastic proliferation of mature myeloid cells, especially granulocytes and basophils.
127
What genetic mutation drives CML?
t(9;22) Philadelphia chromosome, forming the BCR-ABL fusion protein.
128
What is the first-line treatment for CML?
Imatinib, a tyrosine kinase inhibitor.
129
How is CML distinguished from a leukemoid reaction?
CML has negative LAP stain, increased basophils, and t(9;22).
130
What is polycythemia vera (PV)?
Neoplastic proliferation of mature myeloid cells, especially RBCs.
131
What are symptoms of PV caused by hyperviscosity?
Blurry vision, headache, thrombosis, plethora, and post-bathing pruritus.
132
What mutation is associated with PV?
JAK2 kinase mutation.
133
How is PV treated?
Phlebotomy; second-line therapy is hydroxyurea.
134
What distinguishes PV from reactive polycythemia?
PV has low EPO and normal SaO2, whereas reactive forms show increased EPO.
135
What is essential thrombocythemia (ET)?
Neoplastic proliferation of mature myeloid cells, especially platelets.
136
What symptoms are seen in ET?
Bleeding or thrombosis; no significant risk of hyperuricemia or gout.
137
What is myelofibrosis?
Neoplastic proliferation of megakaryocytes, leading to marrow fibrosis.
138
What causes marrow fibrosis in myelofibrosis?
Excess PDGF production by megakaryocytes.
139
What are clinical features of myelofibrosis?
Splenomegaly, tear-drop RBCs, nucleated RBCs, and immature granulocytes.
140
What is lymphadenopathy (LAD)?
Enlargement of lymph nodes.
141
What causes painful LAD?
Acute infections (acute lymphadenitis).
142
What causes painless LAD?
Chronic inflammation, metastatic carcinoma, or lymphoma.
143
What are the regions of hyperplasia in inflammatory LAD?
Follicular (B-cell), paracortex (T-cell), and sinus histiocytes.
144
What is follicular lymphoma?
Neoplastic proliferation of small B cells (CD20+) forming follicle-like nodules.
145
What translocation drives follicular lymphoma?
t(14;18), involving overexpression of Bcl2.
146
How is follicular lymphoma distinguished from reactive follicular hyperplasia?
Disruption of lymph node architecture, lack of tingible body macrophages, and monoclonality.
147
What is mantle cell lymphoma?
Neoplastic proliferation of small B cells expanding the mantle zone.
148
What translocation drives mantle cell lymphoma?
t(11;14), leading to cyclin D1 overexpression.
149
What is marginal zone lymphoma associated with?
Chronic inflammation, such as in Sjogren syndrome, Hashimoto thyroiditis, or H. pylori gastritis.
150
What is Burkitt lymphoma?
Neoplastic proliferation of intermediate-sized B cells (CD20+), associated with EBV.
151
What translocation drives Burkitt lymphoma?
t(8;14), involving c-myc oncogene overexpression.
152
What is the characteristic histological appearance of Burkitt lymphoma?
Starry-sky appearance due to high mitotic index and macrophages.
153
What is diffuse large B-cell lymphoma?
Aggressive neoplastic proliferation of large B cells (CD20+) growing diffusely in sheets.
154
What are Reed-Sternberg (RS) cells?
Large B cells with multilobed nuclei and prominent nucleoli, seen in Hodgkin lymphoma.
155
What markers characterize RS cells?
CD15+ and CD30+.
156
What is the most common subtype of Hodgkin lymphoma?
Nodular sclerosis, presenting with mediastinal or cervical lymphadenopathy.
157
What cytokine is associated with eosinophilia in mixed cellularity Hodgkin lymphoma?
IL-5.
158
What is multiple myeloma?
Malignant proliferation of plasma cells in the bone marrow.
159
What are common features of multiple myeloma?
Lytic bone lesions, hypercalcemia, M spike on SPEP, Rouleaux formation, and risk of infection.
160
What is Waldenstrom macroglobulinemia?
B-cell lymphoma with monoclonal IgM production, causing hyperviscosity symptoms.
161
What are Birbeck granules?
Tennis racket-shaped structures seen in Langerhans cell histiocytosis.
