For undergradutes Revise structure of lymph node and spleen Classify non-neoplastic lesions Various histological patterns Etiologies of each lesion / pattern

1. Non neoplastic lesions of
lymph node and spleen

2. Specific learning objecitves
• Revise structure of lymph node and spleen
• Classify non-neoplastic lesions
• Various histological patterns
• Etiologies of each lesion / pattern

3. Lymphoreticular system

4. Structure of lymph node

5. Histology of lymph node

6. Functions of lymph node
• Immune Response
• Cell mediated and humoral immunity
• T cell, B cells & macrophages

7. When does it bother the patient?
• Lympadenopathy – enlarged – Swelling
• Lymphadenitis – inflammed – Pain

8. Classification
• Acute
– Suppurative
– Non-suppurative
• Chronic

9. Acute lymphadenitis
• Subsequent to
– Microbial infection
– Breakdown products of infective agent
– Cellular debris
– Foreign matter
• Local / generalised

10. Morphology
• enlarged & tender
• maybe fluctuant
• skin – erythematous and warm

11. Acute non suppurative
lymphadenitis
• Follicular hyperplasia
• Prominent germinal center

12. Acute suppurative lymphadenitis
• Necrosis and neutrophilic abscess

13. Chronic lymphadenitis
• 3 patterns:
– Follicular
hyperplasia (B-cell)
– Paracortical
hyperplasia (T-cell)
– Sinus histiocytosis
(Macrophages)

14. Follicular hyperplasia
• Infections or inflammatory processes
• Activate B cells
• Migrate into B cell follicles
• Create the follicular reaction

15. Follicular hyperplasia

16. Follicular hyperplasia
• Numerous B cells • Scattered T cells

17. Follicular hyperplasia
• Tingible body
macrophages
• Meshwork of Antigen
presenting Follicular
dendritic cells

18. Follicular hyperplasia
• Causes
– Rheumatoid arthritis
– Early stage of HIV infection
– Toxoplasmosis

19. Differentiate from follicular
lymphoma
Follicular
hyperplasia
Follicular
lymphoma
Nodal architecture Maintained Effaced
Germinal centers Varying shape
and size
Monotonous
and same
size and
shape
Population of follicular
cells
Polymorphous Monomorphic
Tingible body
macrophages
Present Absent

20. Hyperplasia v/s Lymphoma

21. Paracortical Hyperplasia
• Involve T cell region
• T cells transform into large proliferating
immunoblasts
• Efface the B cell follicles

22. Paracortical hyperplasia

23. Paracortical hyperplasia
• T cell zone expansion
(paracortex)
• Effacement of B cell
zone (follicles)

24. Paracortical hyperplasia
• Causes
– Viral infections (EBV)
– Vaccinations
– Drugs (phenytoin)

25. Sinus Histiocytosis
• Distention and prominence of the
lymphatic sinusoids
• Hypertrophy of lining endothelial cells
• Infiltrate of macrophages (histiocytes)

26. Sinus histiocytosis

27. Sinus Histiocytosis
• Causes
– Normally seen in inguinal lymph node
– Lymph nodes draining cancers

28. Granulomatous lymphadenitis
• Presence of epithelioid granulomas
centered on the sinus
• With or with out caseous necrosis

29. Granulomatous lymphadenitis

30. Granulomatous lymphadenitis
• Causes
– Tuberculosis
– Sarcoidosis
– Leprosy
– Histoplasmosis

31. Structure of Spleen

32. Histology of Spleen

33. Functions of lymph node
• Culling - destroys abnormal / old RBCs
• Pitting - removal of granular inclusions
from RBCs
• Immune function
– contributes to CMI & humoral immunity
• Source of lymphoreticular & hematopoeitic
cells

34. When does it bother the patient?
• Splenomegaly – enlarged

35. Causes
• Inflammatory
• Congestive states
• Infiltrative & storage disorders
• Cysts

36. Inflammatory
• Acute splenic tumor
– Septicemia
– Typhoid
– Inf Mononucleosis
– SABE
– Abscess
• Chronic
– Ch malaria
– Kala azar
– Syphilis
– TB
– Sarcoid

37. Congestive
• Cirrhosis
• Portal or splenic vein thrombosis
• Cardiac failure

38. Congestive
• Early - red pulp
suffused with RBCs
• Later - fibrous &
cellular
• Thickening of
trabeculae
• Fibrosis of red pulp
• Atrophy of
lymphoid tissue
Gamna Gandy body

39. Infiltrative
• Storage of N & abnormal metabolic
products
– Gaucher disease
– Neimann pick disease
– Amyloidosis

40. Infiltrative
Gaucher’s disease

41. Infiltrative
Amyloidosis
Sago spleen / Lardaceous spleen

42. Cysts
•• True cysts
– Parasitic
– Hydatid
– Dermoid
– Lymphangioma
• False Cysts
– Haemorrhagic
– Inflammatory
– Hamartomas

43. Cysts

44. Based on weight
• Massive
• >1000g
– Malaria
– Gaucher
disease
• Moderate
• 500 -1000 g)
– CVC
– Hemolytic
anemia
– Amyloidosis
– Niemann-Pick
– IE
– TB, Typhoid,
Sarcoid
• Mild
• <500 g
– Acute
splenitis
– Acute
splenic
congestion
– Infectious
mononucleos
is
– Septicemia
– SLE

45. Hypersplenism
• Chronically enlarged spleen
• Removes formed elements of blood
• Anemia, Leukopenia, or
Thrombocytopenia
• Platelets susceptible to sequestration in
red pulp
• Thrombocytopenia commoner and severe

46. Summary
• Lesions are classified according to the
region of involvement of a lymph node
• Specific patterns with specific etiologies
• Splenomegaly is classified as per the
etiologies & weight
• Hypersplenism

47. Questions?