Non neoplastic ln revised
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Transcript of Non neoplastic ln revised
Non-neoplastic lesions of Lymph node
Lymphadenopathy
• Inflammations - Acute Chronic nonspecific granulomatous • Neoplastic conditions Primary-Lymphomas Secondary- Metastatic
Reactive Lymphadenitis
• Any immune response against foreign antigens- lymph node enlargement (lymphadenopathy)
• Infections and nonmicrobial inflammatory stimuli involve the lymph nodes, which act as defensive barriers
• Infections that cause lymphadenitis - acute or chronic.
• In most instances, the histologic appearance of the nodes is entirely nonspecific.
PATTERN of LN HYPERPLASIA IN RESPECT TO INFECTIOUS/ INFLAMMATORY DISEASES
FOLLICULAR/NODULAR
INTER FOLLICULAR/PARACORTICAL/ DIFFUSE
SINUS MIXED HYPERPLASIA
GRANULOMATOUS
Castleman Disease Viral lymphadenitis (EMV, CMV, herpes)
Rosai- Dorfman disease
Cat-scratch disease
Tuberculosis
Kimura Disease Post vaccination lymphadenitis
Whipple disease
Kikuchi lymphadenitis
Syphilis
Florid follicular hyperplasia (AIDS)
LCH Toxoplasmosis Toxoplasmosis
Dermatopathic lymphadenopathy
Fungal Infections
SLE Brucellosis
Lymphogranuloma venereum- later stage
ACUTE CONDITIONS:1. Cat-scratch disease2. Lymphogranuloma venereum3. Mesenteric lymphadenitis 4. Staphylococcal infection
CHRONIC CONDITIONS:With eosinophilic predominance1. Kimura’s Disease2. Langerhan’s Cell Histiocytosis3. Castleman’s diseaseGranulomatous4. Tuberculosis5. Atypical Mycobacteriosis6. Syphilis7. Lymphogranuloma venereum8. Sarcoidosis9. BrucellosisNon specific/Non granulomatous10. Leprosy11. WhipplesFungal Infection- HistoplasmosisParasitic-ToxoplasmosisViral-12. AIDS Related
Lymphadenopathy13. Infectious Mononucleosis14. Viral Lymphadenitis
Necrotizing features seen in Acute Conditions:1. Kikuchi necrotising lymphadenitis2. Tularemia3. Fungal infections (early lesions of
histoplasmosis)Miscellaneous-4. Bubonic plague 5. Anthrax6. Melioidosis
Acute Nonspecific Lymphadenitis
• confined to a local group of nodes draining a focal infection, or
• generalized in systemic bacterial or viral infections.
Morphology
• Macroscopically, inflamed nodes- swollen, gray-red, and engorged.
• M/E- large germinal centers with numerous mitotic figures
• Macrophages often contain particulate debris of bacterial origin or derived from necrotic cells.
Acute suppurative lymphadenitis
• Cause is a pyogenic organism, a neutrophilic infiltrate -seen about the follicles and within the lymphoid sinuses
• With severe infections, centers of follicles undergo necrosis - abscess
• Affected nodes - tender,firm • If abscess extensive - fluctuant and soft• Overlying skin red, and penetration of the
infection to the skin - draining sinuses• With control of the infection, the lymph nodes
can revert to their normal appearance or,• if damaged by the immune response, undergo
scarring
Chronic Nonspecific Lymphadenitis
• Three morphological patterns, depending on the causative agent:
follicular hyperplasia, paracortical hyperplasia, or sinus histiocytosis
Follicular Hyperplasia
• Cause – any stimuli that activate B-cell immune response.
• Large oblong germinal centres(Secondary follicle light zone) surrounded by collar of mantle zone(resting naïve B-cells- dark zone).
• Normal germinal centres: - Polarised
Follicular Hyperplasia
• Tingible body macrophages:- Macrophages pred. found in germinal centres.- Interspersed b/w germinal centers- Contain immunoblast nuclear debris.- immunoblasts undergo apoptosis- if fail to
produce Ab with high affinity to Ag.
Causes of follicular hyperplasia
• Non-specific reactive follicular hyperplasia• rheumatoid arthritis, • toxoplasmosis, and• the early stages of HIV infection• Kimura disease
Architectural Features
Follicular Hyperplasia1)Preservation of nodal
architecture.2)Follicles-more prominent in
cortical portion.
3) Size & shape of follicles- marked variation(elongated, angulated, dumb-bell forms).
4)Reaction centre- sharply demarcated
Follicular lymphoma1)Complete effacement of
normal architecture2)Evenly distributed
throughout cortex and medulla.
3)Size & shape of follicles- moderate variation.
4)Fading of follicles
Follicular Hyperplasia Vs Follicular Lymphoma
Follicular hyperplasia Follicular lymphoma
Paracortical Hyperplasia
• characterized by reactive changes within the T-cell regions of the lymph node.
• On immune activation, parafollicular T cells transform into large proliferating immunoblasts that can efface the B-cell follicles.
• Eg: viral infections ( EBV), following certain vaccinations (e.g., smallpox),
• immune reactions induced by certain drugs (eg:phenytoin).
Sinus Histiocytosis
• distention and prominence of the lymphatic sinusoids, due to marked hypertrophy of lining endothelial cells and an infiltrate of macrophages (histiocytes).
• Seen in lymph nodes draining cancers and may represent an immune response to the tumor or its products.
• Rosai Dorfman Disease.(sinus histiocytosis with massive lymphadenopathy.)
Sinus Histiocytosis/S.Hyperplasia
Chronic Granulomatous Lymphadenitis
• non-necrotising: Sarcoidosis• Necrotising: TB,Cat-scratch disease, Fungal infections, lymphogranuloma venereum
TB-matted LN,caseous necrosis
Tuberculous Granulomatous Lymphadenitis
Caseous necrocis
Langhan’s GC