1. Lymph node pathology

2. Lymph node histology Functions Filtration of lymph Processing of Ag
Differentiation of lymphocytes

3. Secondary lymphoid follicle
Germinal centre
mantle

4. Terminology Lymphadenopathy Lymphadenomegaly Lymphadenitis
Lymphoproliferation
Lymphoma
Enlargement of LN: inflammation
Tumor – primary/secondary

5. Lymphadenitis acute or chronic
Rarely biopsied
Classification
predominant histologic pattern
etiology

6. Lymphadenitis - etiology
MICROBIAL
viral
bacterial, mycobacterial
fungal
protozoal
NONMICROBIAL - autoimmune
storage dis.
foreign mat.
miscel.

7. Lymph node inflammation
Lymph node hyperplasia:
1. follicular
2. paracortical
3. sinuses
4. mixed patterns

8. Lymph node inflammation - patterns
Follicular hyperplasia
bacteria, RA, HIV(early), syphilis,
Castleman dis.
Paracortical hyperplasia
viruses, dermatopathies, vaccination,
drug hypersensitivity, Kikuchi, SLE,
draining pus or carcinoma

9. Lymphadenitis - histological patterns
sinusoidal hyperplasia - lymphangiography, Whipple dis., sin. histiocytosis with massive lymphadenopathy, draining carcinoma
granulomas - TB, other mycobact., leprosy, Whipple, fungi, berylliosis, sarcoidosis,
Granulomatous-purulent:cat scratch, tularemia, lymphogr. venereum,Yersinia
mixed patterns: toxoplasmosis

10. Regressive transformation of germinal centres

11. Follicular hyperplasia

12. Progressive transformation of germianl centres

13. Sinus histiocytosis

14. Lepra - globi

15. Infectious mononucleosis

16. Cat scratch disease

17. Kikuchi lymphadenitis

18. Bartonella henselae Ct scratch disease

19. CMV

20. Kimura disease

21. Cryptococcosis

22. Atypical mycobacteriosis

23. Lymphogranuloma venereum

24. Mycobacterium TB

25. Pneumocystosis

26. Syphilis

27. TBC

28. Toxoplasmosis

29. Whipple disease

30. Sinus histiocytosis
with massive lymphadenopathy