Term
| what is the most common cause of reactive lymphadenopathy? |
|
Definition
|
|
Term
| what is the best way to start looking at pathology under a microscope? |
|
Definition
|
|
Term
| what are some general patterns of benign reactive lymphadenopathy? |
|
Definition
| several broad patterns, follicular, sinus infiltration, diffued, paracortical, and mixed |
|
|
Term
| what is a reactive lymph node condition that can mimic follicular malignant conditions? what is seen with these histologically? |
|
Definition
| nonspecific follicular hyperplasia; which varies in size, shape and number of follicles. it is often seen in children/adolescents. histologically, follicular hyperplasia is seen with tingible body macrophages (coming into clean up dead cells resulting from over-proliferation - similar to burkitt) |
|
|
Term
| what is seen in paracortical hyperplasia? |
|
Definition
| this is a benign hyperplasia of lymphocytes surrounding the cortex |
|
|
Term
| when can necrotizing lymphadenitis occur? |
|
Definition
| this is seen in children as a result of infection, sometimes inflammtory infiltrates can occude lymphocytes (plasma cells, neutrophils). caseating necrosis may be a sign of TB (includes PMN, eosinophils -> associated with massive lymph nodes typically in mediastinal/paratracheal/inguinal LN regions) |
|
|
Term
| is necrosis seen usually with lymphomas? |
|
Definition
|
|
Term
| what is toxoplasmosis lymphadenitis characterized by? |
|
Definition
| *unilateral posterior lymph nodes, reactive follicular hyperplasia, and small aggregates of epithelial histiocytes- which encroach on follicles (pink puffs). it is marked by a *monocytoid B cell hyperplasia seen in subscapular and trabecular sinuses. the toxoplasma cysts may be visible |
|
|
Term
| what is toxoplasmosis associated with? |
|
Definition
|
|
Term
| can syphilis produce a follicular lymph node hyperplasia? |
|
Definition
| yes, syphilis generally surrounds blood vessels (may cause periarteritis). **plasma cells are a trademark of syphillis. epithelial histiocytes, a thick capsule and solitary inguinal lymphadenopathy may be observed. spirochetes may also be visible in blood vessel walls |
|
|
Term
| what is granulomatous lymphadenitis seen in conjunction with? |
|
Definition
| kikuchi, cat-scratch disease, and lymphogranuloma venerum |
|
|
Term
|
Definition
| this is seen more in young women, presenting with fever (similar to SLE). it features necrosis, aggregates of macrophages with C-shaped nuclei and CD8+ immunoblasts in interfollicular areas. the necrotic areas feature karyorrhectic debris and a *paucity of neutrophils. plasmacytoid monocytes w/round nuclei and eosinophilic cytoplasm - hybrid cells are also seen |
|
|
Term
| what is characteristic of sarcoidosis? |
|
Definition
| these are characterized by well-circumscribed epithelioid granulomas with asteroid bodies (stellate), schaumen bodies (circular laminar concretions), and **calcium oxalate crystals. it typically presents in the lungs, peritracheal lymph nodes, but can be anywhere. it is often seen in blacks and manifests as respiratory and possibly cardiovascular symptoms. **this is a dx of exclusion |
|
|
Term
| what is cat scratch fever characterized by? |
|
Definition
| supprative granulomas with **stellate (necrotic) absecesses, surrounded by pallisading macrophages/histiocytes; esp in germinal centers. follicular hyperplasia is commonly seen as well. |
|
|
Term
| what organsims is cat scratch fever associated with? |
|
Definition
| bartonella henslae, which can further cause bacillary angiomatosis in immunocompromised hosts (B. henselae wreaks havoc via dermal lesions, increased capillary formation, plump endothelial cells, and granular eosiniphilic material*) |
|
|
Term
| what is lymphogranuloma venereum? |
|
Definition
| this is similar to cat scratch diseae (not as much stellate hyperplasia), but includes chlamydia and is IDed via a negative silver stain |
|
|
Term
| what is HIV related hyperplasia? |
|
Definition
| this is related to extravasation of RBCs into germinal centers, thinning/elimination of mantle zones and **warhin-finkeldey cells which feature multiple nuclei and eosinophilic intranuclear inclusions. this may act as an HIV marker, so a stain for HIV core protein p24 should be done. as immunosuppression progresses the pattern changes from follicular hyperplasia (explosive, florid, and geographic) to follicular involution and finally lymphocyte depletion |
|
|
Term
| what are some reasons for diffuse lymphadenopathy? |
|
Definition
| infectious mononucleosis, postvaccinal lymphadenitis (adverse vaccine rxn), and dilantin hypersensitivity (anti-seizure meds). these may co-present with general symptoms such as malaise and fever (mimic leukemia) |
|
|
Term
| what can diffuse reactive lymphadenopathy to mono look like? |
|
Definition
| it may appear like a lymphoma, with interfollicular expansion of many immunoblasts/lymphocytes giving a mottled appearance. immunoblast cells may resemble reed sternberg cells. leukemia and lymphoma should be in the differential |
|
|
Term
| what is post-vaccinial lymphadentitis seen with? |
|
Definition
| smallpox. this can resemble infectious mono (rely on pt hx for dx). it also has a vascular mixe-cell infiltrate |
|
|
Term
| what characterizes dilantin hypersensitivity? |
|
Definition
| diffuse reactive lymphadenopathy, fever, erythematous rash and eosinophilia. the rash can develop into toxic epidermal necrolysis (one of the few dermatologic emergencies). immunoblasts, eosinophils, and plasma cells are seen w/this |
|
|
Term
| what is a common cause of benign lymphadenitis? how does it present? |
|
Definition
| viral. it presents with a large population of monocytes & lymphocytes w/interspersed macrophages |
|
|
Term
| can RA cause follicular hyperplasia? |
|
Definition
| yes, usually w/interfollicular plasmacytosis similar to syphilis. there may be russel bodies and an **increased risk of lymphoma |
|
|
Term
| can SLE cause lymphadenopathy? |
|
Definition
| yes - and necrotic debris can be present which may be painful/painless |
|
|
Term
| what are the three types of castleman's disease? |
|
Definition
| hyaline vascular, plasma cell type, multicentric |
|
|
Term
| what characterizes the hyaline vascular type of castleman's disease? |
|
Definition
| hyaline vascular is the more common form of castleman's and is characterized by mantle-zone **hyperplasia w/concentric layering of cells - "onion skin" which is then **penetrated by (sclerotic) vessels resembling a "lollipop". lymph nodes affected by this often have **2+ germinal centers. |
|
|
Term
| what characterizes the plasma cell type of castleman's disease? |
|
Definition
| this is composed of sheets of plasma cells, is often symptomatic |
|
|
Term
| what characterizes the multicentric type of castleman's disease? |
|
Definition
| multicentric castlemans is aggressive and linked to HHV-8 |
|
|
Term
| what is the pattern of lymph node sinus infiltration? |
|
Definition
| rosai-dorfman syndrome, kimura's disease, and whipple's disease |
|
|
Term
| what is rosai-dorfman syndrome? |
|
Definition
| high level of sinus histiocytosis w/massive lymphadenopathy (cervical, nontender). this is common in people up to 20 yrs old and presents with matted lymphadenopathy, dialated sinuses, fever, neutrophilia and elevated ESR. histiocytes, S100+ (cell antigen protein stain)*, macrophages w/emperiopolesis (in vivo phenomenon in which one cell is completely engulfed into another)* |
|
|
Term
| what is kimura's disease? |
|
Definition
| lymph node sinus infiltration similar to rosai dorfman; proliferation/accumulation of lymphocytes surrounding the follicle, which ruptures node architecture |
|
|
Term
|
Definition
| lymph node sinus infiltration marked by *foamy macrophages and sickle-shapped bacillary organisms (tropheryma whippelii). it is associated with *malabsorption in the GI, *hyperpigmentation and *CNS changes. (other changes: weight loss, anemia, tetani*, seizures, easy bruising due to lack of K+). this is seen more in males |
|
|
Term
| what is virus associated hemophagic syndrome? |
|
Definition
| this is characterized by *bland macrophages which ingest *RBC, neutrophils and platelets. it is seen in younger children with pancytopenia/neutropenia and constitutional symptoms. this can look like leukemia (if infiltrates the bone marrow) |
|
|
Term
| what is dermatopathic lymphadenitis? |
|
Definition
| this is similar to mycosis fungoides, featuring *pigment laden macrophages and *paracortical/interfollicular expansion of large cells. dermatopathic lymphadenitis is associated with skin diseases especially *exfoliative dermatitis |
|
|
Term
| what is autoimmune lymphoproliferative syndrome? |
|
Definition
| ALPs features lymphadenopathy, splenomegaly and *hypergammaglobulinemia. it has autoimmune features and is associated with the genetic type mutation of *FAS (CD95 as well as caspase 10) that generally activates apoptosis. paracortical follicular hyperplasia is seen w/transformation of germinal centers. *CD5+ B cells are seen in peripheral blood and there is an *increased risk of lymphoma |
|
|
Term
| what is kawasaki's disease? |
|
Definition
| mucocutaneous lymph node syndrome. pts may present w/ conjunctivitis, coronary artery involvement (in carotids). there is lymphoid depetion *(absence of follicles) and obliteration of nodal architecture. necrosis/thrombi is seen in vessels, (on differential for childhood MIs). -> “Kawasaki”, “Mucu-Kutaneous LN syndrome”, “Konjunctivitis”, “Koronary Artery Development”, “Ne-Krosis”, “absence of folli-Kles”, etc |
|
|
