Reactive lymph nodes Flashcards
Benign process that can extend into perinodal tissue
Infectious mononucleosis
Scientific name of syphilis
Treponema pallidum
Toxoplasma triad
Follicular hyperplasia
Sinusoidal monocytoid B cells
Epithelioid histiocyte aggs in mantle zone
Cat scratch disease clinical features
Bartonella henselae
Inocculation site - erythematous papule, lymphadenopathy of draining nodes
Fever, malaise
Cat scratch disease microscopic features
Capsulitis
Follicular hyperplasia
Germinal centre abscesses with palisaded granuloma surrounding
Endothelial cell swelling with organisms within, seen on Warthin Starry stain
Differentials of LNs with granulomatous abscesses
Lymphogranuloma venereum (Chlamydia trachomatis) Tularemia - arthropods Kikuchi-Fujimoto (histiocytic necrotising lymphadenitis) TB/BCG Yersinia Pseudemonas mallei Crohn's Schistosomiasis Leishmaniasis Lepromatous leprosy (ZN stain +ve) Mycobacterium avium intracellulare Histoplasmosis
CMV lymphadenitis histological features
Follicular hyperplasia Monocytoid B cell hyperplasia Infected cells with red nucleus, look like RS cell and CD15 +ve but also CMV +ve (immuno and FISH) Histiocytes and neutrophils Endothelial cells also infected
Kikuchi-Fujimoto clinical features
Tender unilateral cervical lymphadenopathy
Fever, rash, anaemia
Kikuchi-Fujimoto pathological features
Karryorectic debris and eosinophilic material, surrounded by histiocytes and immunoblasts
FEW neutrophils, no granulomas
Small lymphcytes surrounding necrosis are CD8+ve T cells, may express CD30
Can partially involve node (unlike lymphomas)
Differentials of Kikuchi-Fujimoto
NHL e.g. DLBCL
Lupus lymphadenitis - Can look exactly the same + Azzapardi phenomenon, haematoxylin bodies
Herpes simplex virus histology
Paracortical hyperplasia
Necrotic areas containing cells with intranuclear inclusions
Histiocytes but no granulomas
Immuno, ISH, culture
Plasma cell variant Castleman’s histologic features
Interfollicular expansion by plasma cells
A few hyaline vascular-type follicles or hyperplastic follicles
Plasma cells may express monotypic Ig, usu IgG or IgA lambda
Always do HHV-8
DDX plasma cell variant Castleman’s
Autoimmune diseases (RA, lupus)
Plasmacytoma
Lymphoplasmacytic lymphoma
Always do HHV-8
DDX hyaline vascular Castleman’s
Mantle cell lymphoma
Follicular lymphoma
Mast cell disease clinical associations
Cutaneous mastocytosis
Systemic mastocytosis
Mast cell leukaemia, sarcoma
Associated with other haematological diseases
Mast cell disease histopathology
Medullary cords and paracortex
Spindle cells, binucleate
Can look like plasma cells on H+E, or clear cytoplasm
Mast cells CD117, CD2, mast cell tryptase, CD68 +ve
Romanovsky stains: Wright, Giemsa
Metachromatic stains: Toledine blue, ZN
Rosai-Dorfman clinical associations
Monoclonal hypergammaglobulinaemia, raised ESR
Cervical lymphadenopathy, also skin, lungs, bone
Haemolytic anaemia
Localised disease benign
Systemic disease poor prognosis
Rosai Dorfman histology
Massive sinus histiocytosis
Emperipolesis
Plasma cells in medulla
Immuno: S100+ve, CD68 +ve, CD1a -ve
Rosai Dorfman differentials
Sinus histiocytosis Mycobacteria esp MAI in immunocompromised Langerhans cell histiocytosis Metastasis ALCL
Langerhans cell histiocytosis histopathology
Langerhans cells Eosinophils Plasma cells Fibrosis Immuno: CD1a, S100, CD45, weak CD68 +ve. CK, vimentin -ve Birbeck granules diagnostic
LCH clinical
3 forms: Eosinophilic granuloma Systemic Hand-Schuller-Christian (diabetes insipidus, lytic skull lesions) Treated with surgery, radiation, chemo
Granulomatous lymphadenitis differentials
Mycobacteria
Fungal infection (blastomycosis, histoplasmosis, coccidiomycosis)
Sarcoid
Kikuchi
Cat-scratch, yersinia, lymphogranuloma venerum
Foreign body granulomas
ALCL histologic features
Horseshoe/doughnut cells characteristic Sinusoidal Immuno: CD30 (cytoplasmic, golgi), CD45, T-cell phenotype (can lose some antigens), null cell (but TCR rearrangement on genetic), EMA, ALK1 PAX-5 always -ve Genetics: t(2;5) translocation ALK-NPM
ALCL clinical features
Bimodal age
Lymphadenopathy and B symptoms
Extranodal masses - skin, bone, ST, lung, liver
Prognosis related to ALK (favourable)
Lymphoplasmacytic lymphoma clinical
Older males
Rare
IgM paraproteinaemia
Ass c Waldenstrom’s MG and bone marrow involvement
Lymphoplasmacytic lymphoma histology
Spectrum of small lymphocytes, plasmacytoid lymphocytes, plasma cells, immunoblasts
Paracortial infiltration, sinuses intact
Ducher bodies (nuclear), Russel bodies (cytoplasmic)
CD19, 20, surface Igs, IgM +ve
CD5, CD10 -ve
Chromosome 6 deletion in WM
Extranodal NK/T-cell lymphoma, nasal type histology
Angioinvasive, angiodestructive CD2 +ve, CD3, CD56 NK: TCR ab and yb -ve T-cell: positive EBV +ve
