Describe the transit of B cells into and out of the lymph node
Travel through:
- bone marrow (maturation)
- blood
- enter lymph node through high endothelial venule (HEV)
- migrate to cortex
- begin in the mantle zone (naive)
- clonal expansion in follicular germinal center in response to antigen
- migrate to marginal zone and become memory B cells or differentiate into plasma cells
- exit via efferent lymphatics
Describe the transit of T cells into and out of the lymph node
Travel through:
- Thymus (maturation)
- blood
- enter lymph node through HEV
- migrate to paracortex
- clonal expansion in the paracortex in response to antigen
- exit via efferent lymphatics
Describe the lymphadenopathy observed in this specimen. How severe would a patient’s fever be and would they have mono or polyclonal B/T cells?
Indicative of an infection (some increase in secondary follicles due to mounting of immune response)
- localized, mild lymphadenopathy
- low grade fever
- polyclonal B/T cells
Describe the lymphadenopathy observed in this specimen. How severe would a patient’s fever be and would they have mono or polyclonal B/T cells?
Indicative of neoplasm (cellular atypia and no secondary follicles)
- extensive, marked lymphadenopathy
- drenching night sweats
- monoclonal B/T cells
Describe the duration, size, location, tenderness, mobility and consistency of a benign lymphadenopathy
- duration= < 2 weeks
- size= < 2 cm (1 cm= normal)
- location= cervical, inguinal
- tenderness= tender
- mobility= mobile
- consistency= soft
Describe the duration, size, location, tenderness, mobility and consistency of a malignant lymphadenopathy
- duration= > 2 weeks
- size= > 2 cm (1 cm= normal)
- location= supraclavicular
- tenderness= non-tender
- mobility= fixed
- consistency= firm, hard
Describe the architecture, dominant cell type, atypia, and ancillary study (flow cytometry) findings of benign lymphadenopathy
- architecture= intact
- dominant cell type= small lymphs
- atypia= none
- ancillary study findings= polyclonal
Describe the architecture, dominant cell type, atypia, and ancillary study (flow cytometry) findings of malignant lymphadenopathy
- architecture= effaced
- dominant cell type= large lymphs/epithelial cells
- atypia= present
- ancillary study findings= monoclonal
What are B symptoms? What do they usually represent and how are they used?
- generalized symptoms found in either reactive or neoplastic lymphadenopathy
- fever
- night sweats
- weight loss (>10% body weight in 6 months)
- usually seen in neoplasms (incorporated into staging systems for lymphoma)
What are some causes of reactive lymphadenopathy?
- infectious
- autoimmune
- drugs
- foreign body (e.g. orthopedic surgery)
- Castleman’s disease
- Sarcoidosis
- Kikushi-Fujimoto
- Kimura’s disease
- Rosai disease
What are some causes of neoplastic lymphadenopathy?
- lymphoma
- leukemic involvement
- lymphoblastic lymphoma
- myeloid sarcoma
- metastatic tumor (most common!)
What are 6 histologic patterns of reactive lymphadenopathy (and what disease processes cause them)?
- follicular hyperplasia
- autoimmune, early HIV, toxoplasmosis
- paracortical hyperplasia
- EBV, CMV, herpes, drugs
- sinus histiocytosis
- draining tumors
- necrotizing
- cat scratch, bacterial, fungal, autoimmune, viral
- granulomatous
- fungal, TB, sarcoidosis
- mixed
What does this image show?
Follicular hyperplasia
What does this image show?
Paracortical hyperplasia
What does this image show?
Sinus histiocytosis
What does this image show?
Granulomatous inflammation
What are two major differentials to consider if you saw this biopsy image?
- follicular lymphoma (more likely due to crowding)
- follicular hyperplasia (benign; less likely)
What is a common treatment plan for follicular lymphoma?
- Indolent/slow growth common so early treatment may be “watchful waiting”
- 40% of cases transform to more aggressive lymphoma (may present as increased fatigue or show on CT scan)
- Once symptoms begin, treat with chemotherapy and anti-CD20 monoclonal antibody therapy
Describe follicular lymphoma; what is its prevalence?
- 60 yo median age, slight male predominance
- nodal > extranodal
- extensive, generalized adenopathy
- 20% of all lymphomas; 1/3 of B cell lymphomas
What is the genetic variation that common causes follicular lymphoma?
Most characterized by t(14;18)
What is the disease progression of follicular lymphoma?
- generally indolent
- 40% transform to aggressive lymphomas
- diffuse large B cell lymphoma
- Burkitt lymphoma
What does this image show?
- “starry sky” appearance of Burkitt lymphoma
- increased cellularity= “sky”
- lighter macrophages= “stars”
What are the B cell non-hodgkin lymphomas (NHLs) we need to know (6)?
- follicular lymphoma
- diffuse large B cell lymphoma
- mantle cell lymphoma
- marginal zone lymphoma
- lymphoplasmacytic lymphoma
- Burkitt lymphoma
What are the morphologies that help differentiate the B cell NHLs?
- nodular, follicular
- follicular lymphoma
- mantle cell lymphoma
- marginal zone lymphoma
- CLL/SLL
- diffuse
- diffuse large B cell lymphoma
- Burkitt lymphoma
-
1 - Hematopoiesis32
-
2- VM46
-
3- Introduction to White Blood Cell Disorders, Reactive and Neoplastic Myeloid Processes75
-
4- Introduction to WBC Disorders Reactive an Neoplastic Myeloid Processes Targeted Leukemia Therapy39
-
5 - B and T cell Devo34
-
6a- Lymphocytosis and Lymphoid Leukemias41
-
6b- Lymphocytosis/lymphoid leukemia23
-
7- Plasma Cell Dyscrasias21
-
8- Lymph node VM8
-
9a- Lymphadenopathy42
-
9b- EBV11
-
Cytogenetics16
