Please enable JavaScript.
Coggle requires JavaScript to display documents.
LYMPH NODES (LYMPHADENOPATHY (Non-neoplastic causes (Reactive Hyperplasia,…
LYMPH NODES
LYMPHADENOPATHY
Localised / widespread
Needs biopsy to diagnose
Very common
Causes:
Infections
Neoplasms
Autoimmune disorders
Non-neoplastic causes
LN respond to inflammatory stimuli by cellular proliferation thereby leading to enlargement of LN
A macrophage response which is linked to sinus & pulp histiocyte hyperplasia
Mixed response where all cellular elements are activated & proliferate
Predominately B cell response with germinal centre hyperplasia
Predominately T cell response with paracortical expansion
This occurs due to any of these:
Reactive Hyperplasia
Mixed response
Occurs in LN draining sites of infection
Lymphadenitis
Pathogenic organisms cause inflammatory changes
Can progress to abscess formation
Specific non-infective disorders
Follicular hyperplasia
Anything causing proliferation of B cells leads to this
Rheumatoid Arthritis
Involves many LN groups
Very common (75%)
Microscopic:
Follicular hyperplasia with many plasma cells in medulla
Sinus histiocytosis
Langerhan cell histiocytosis (histocytosis X)
Clusters of typical pale Langerhan cells with folded nuclei may be seen among giant cells & eosinophils
May affect LN & involves sinuses
Sinus histiocytosis with massive lymphadenopathy (SHML)
May affect any age or organ
Beningn
Presents with bulky cervical lymphadenopathy
Common in Black people
Rare & idiopathic
Microscopic:
LN sinuses distended by large histiocytic cells mixed with lymphocytes & plasma cells
Necrotising lymphadenitis
Systemic Lupus Erythematous
Microscopically similar to Kikuchi disease
Kikuchi's disease
Usually affects young adult women
Idiopathic
Tender cervical or occipital lymphadenopathy
Paracortical hyperplasia
Dermatopathic Lymphadenopathy
Develop enlarged groin & axillary LN
Cut surface of LN is yellow / brown
Patients with exfoliative skin conditions e.g.
Psoriasis
Cutaneous T-cell Lymphoma
Severe eczema
Microscopic:
Paracortex expanded by pale histiocytes , some containing melanin.
Prominent feature is lymphadenopathy
Granulomatous lymphadenitis
Rxn to tumor antigen
Foreign body rxn
Response to silicone compounds used in plastic surgery & joint replacement
Crohn's disease
Causing inflamm. of digestive tract
Inflammatory bowel disease
Leads to abdo. pain, severe diarrhoea, malnutrition, fatigue & weight loss
Fistulas
GIT bleeds when ulcers perforate causing anaemia
Sarcoidosis
Inflammatory disease affecting multiple organs esp. lungs & LN
In affected people, abnormal masses( granulomas) consisting of inflammed tissues form
Specific infective disorders
Follicular hyperplasia
Treponema Pallidum (Syphils)
Primary
Occurs in nodes draining chancre (inguinal)
Secondary
Generalised lymphadenopathy
Occurs at any stage of acquired / congenital syphilis
Histology
Follicular hyperplasia
Many plasma cells in interfollicular areas
Paracortical hyperplasia
Infectious mononucleosis
Widespread lymphadenopathy
Paracortical hyperplasia with numerous large transformed T cells
Due to Epstein Barr Virus
Necrotising lymphadenitis
Lymphogranuloma Venereum
Affects groin nodes
Stellate abscesses with LN surrounded by palisaded histiocytes
Sexually transmitted chlamydial disease
Variety of diseases caused by infectious agents may lead to necrosis within LN
Cat stratch disease
Cervical, axillary & groin areas(less common)
Caused by Bartonella henselae
In days / weeks later, tender lymphadenopathy develops
Stellate abscesses within lymph nodes surrounded by palisaded histiocytes
Occurs after a bite / scratch from an infected cat
HIV
Microscopic:
Focal destruction of dendritic reticulum cell meshwork which is linked to implosion of mantle zone lymphocytes
@ later stages, there's loss of germinal centre B cells & depletion of paracortical T cells
Initially follicles are hyperplastic & irregularly shaped
May be seen with systemic symptoms in:
Persistent generalised lymphadenopathy(PGL) syndrome
Persists for more than 3 months
Persistent extra-inguinal lymphadenopathy in two / more adjacent sites
AIDS related complex
Diarrhoea
Nocturnal sweats
Unexplained lymphadenopathy
Oral candidiasis
Weight loss
Very common
Granulomatous Lymphadenitis
Toxoplasmosis
In immunocompeten host, it causes a brief flu-like illness & localised lymphadenopathy
Nodes affected are occipital / high cervical nodes
Due to Toxoplasmosis Gondii
Histological Triad that suggests diagnosis:
Follicular hyperplasia
Adjacent granulomas
Marginal zone B cell hyperplasia
Mycobacterial infection
Structure
Macroscopic
Discrete and encapsulated
Found along the course of lymphatic vessels
Ovoid
Microscopic
Lymph passes from subscapsular sinus to medullary cords to hilium to efferent lymphatic drains
Subscapsular sinus in which afferent lymphatics drain after penetrating the capsule
CT capsule with trabeculae which extends into substance of node
DIstinct Zones
Paracortex
T cell dev. region
Medulla
Contains medullary cords & sinuses which drain into hilium
Contains plasma cells
Cortex
Contains nodules of B cells either as primary follicles or germinal centres