9a- Lymphadenopathy Flashcards
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