Immuno 4

Question 1

Lymphopenia (lymphocytopenia)-nonprolif WBC disorder

Answer 1

Not very common
Often secondary to disease or therapy/drugs
Reduced lymphocytes in blood (

Question 2

Leukopenia (leukocytopenia)-nonprolif WBC disorder

Answer 2

Reduced granulocytes

Neutropenia as reduced neutrophils (

Question 3

Leukocytosis-Reactive proliferative WBC disorder

Answer 3

Classified according to cellular subtype
Neutrophilic leukocytosis:
As a result of bacterial infection or sterile inflammation (burns, myocardial infarction)
Eosinophilic leukocytosis (eosinophilia):
As a result of allergic reactions, parasitic infections
Basophilic leukocytosis (basophilia)
not common, usually associated with other conditions such as neoplastic disease
Lymphocytosis:
often associated with chronic infections

Question 4

Leukocytosis in Infectious mononucleosis

Answer 4

Caused by EBV infection
Characterized by fever, sore throat, lymphadenitis & lymphocytosis of CD8+ T cells
Monospot test is diagnostic

Question 5

Lymphadenitis

Answer 5

Reactive proliferative WBC disorder
Lymphadenitis (inflammation of lymph node) is usually associated with lymphadenopathy (enlargement/swelling)
Cat scratch lymphadenitis by Bartonella henselae

Question 6

Acute lymphadenitis is characterized by

Answer 6

enlarged B cell germinal centers

Question 7

Chronic lymphadenitis occurs as:

Answer 7

Follicular hyperplasia: Activated B cells migrate into follicular zone
Paracortical (mantle) hyperplasia: Activation of interfollicular T cells that proliferate and displace B cell germinal centers
Sinus histiocytosis (draining sinuses): Distention of lymphatic sinusoids due to endothelial hypertrophy and infiltration of macrophages (histiocytes)

Question 8

Neoplastic WBC Disease

Answer 8

Malignant leukocytes arise form either myeloid (RBC/granulocyte series) or lymphoid (T/B) cells representing arrested development
Cancers arising from early progenitor cells will be ‘blastic’ cancers (acute lymphoblastic leukemia)
WBC cancers arising in the bone marrow/thymus are leukemias
WBC cancers arising from germinal lymphoid tissues are lymphomas
‘acute’ vs ‘chronic’

Question 9

Acute Lymphoblastic Leukemia/Lymphoma (ALL)

Answer 9

ALLs constitute 80% of childhood leukemias
B-cell origin in children by 4 years, while T-cell origin late teens
Clinically manifests as abrupt onset with anemic fatigue, fever from infections, bleeding, bone pain
Generalized lymphadenopathy, splenomegaly & hepatomegaly as well as CNS symptoms (vomiting, headaches) are more common in ALL than CML

Question 10

B-ALLs can have

Answer 10

the 9:22 translocation of Philadelphia chromosomes as in CML, usually non-random karyotypic abnormalities

Question 11

Acute myeloid leukemia (AML)

Answer 11

Myeloproliferative disorders result from acquired genetic abnormalities in myeloid cell progenitors that lead to excessive proliferation and diminished function

• AML neoplastic block of myeloid blast cell differentiation
• Auer rods

Question 12

Chronic myeloid leukemia (CML) & Philadelphia chromosome

Answer 12

CML is a chronic myeloproliferative disorder with large numbers of mature, but functionally abnormal myeloid (granulocyte) cells
-Associated with Philadelphia chromosome, a translocation between the bcr gene & abl proto-oncogene: t(9;21)
Generally affects adults (25-60 years) with initial onset of disease with nonspecific symptoms

Question 13

Hodgkin’s Lymphoma

Answer 13

Classical Hodgkin’s disease demonstrates a moderate number of Hodgkin’s cells with identifiable Reed-Sternberg cells
Reed-Sternberg cells have a characteristic morphologic appearance with a bilobed (mirror image), nucleus prominent eosinophilic nucleoli and a moderate-to-abundant amount of cytoplasm
Large cells measuring 15-45 um
typically express CD30, CD15

Question 14

Hodgkin’s (vs non)

Answer 14

Usually localized to single group of nodes
Orderly, contiguous (direct) spread
Mesenteric nodes and Waldeyer ring (tonsillar/nasal-associated lymphoid tissue) rarely involved
Extranodal involvement uncommon

Question 15

nonHodgkin’s

Answer 15

Frequent involvement of peripheral nodes
Noncontiguous spread
Mesenteric nodes and Waldeyer ring involvement
Extranodal involvement common

Question 16

Hodgkin’s: Nodular sclerosis

Answer 16

Most common form of Hodgkin’s
Typically involves cervical, supraclavicular & mediastinal lymph nodes
‘Lacunar’ type RS cells that is multilobulated

Question 17

Hodgkin’s: Mixed cellularity

Answer 17

Most common form of Hodgkin’s in pts >50 years with male predominance
Disseminates more than nodular sclerosis type
Lacks dense bands of collagen seen in NS, but abundant eosinophils & Hodgkin’s cells

Question 18

Hodgkin’s: Lymphocyte-predominace

Answer 18

RS cells have multilobed, puffy nucleus

B cells express fail to express CD15 & CD 30 unlike other RS cells