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

Lymph node pathology

Lymph node histology

FunctionsFiltration of lymphProcessing of AgDifferentiation of lymphocytes

Secondary lymphoid follicleGerminal centremantle

Terminology

• Lymphadenopathy

• Lymphadenomegaly

• Lymphadenitis

• Lymphoproliferation

• Lymphoma

• Enlargement of LN: inflammation

• Tumor – primary/secondary

Lymphadenitis

acute or chronic

Classification

predominant histologic pattern

etiology

Rarely biopsied

Lymphadenitis - etiologyMICROBIAL

• viral

• bacterial, mycobacterial

• fungal

• protozoal

NONMICROBIAL - autoimmune

storage dis.

foreign mat.

miscel.

Lymph node inflammation

Lymph node hyperplasia:

1. follicular

2. paracortical

3. sinuses

4. mixed patterns

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

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

Regressive transformation of germinal centres

Follicular hyperplasia

Progressive transformation of germianl centres

Sinus histiocytosis

Lepra - globi

Infectious mononucleosis

Cat scratch disease

Kikuchi lymphadenitis

Bartonella henselaeCt scratch disease

CMV

Kimura disease

Cryptococcosis

Atypical mycobacteriosis

Lymphogranuloma venereum

Mycobacterium TB

Pneumocystosis

Syphilis

TBC

Toxoplasmosis

Whipple disease

Sinus histiocytosis with massive lymphadenopathy