An A-to-Z atlas of lymph node pathology. This is the permanent archives from the same effort shared on Twitter during June of 2018. One new letter each day with matching cases.
I hope you find these images useful as you encounter unusual lymph node entities. I have omitted, by design, common lymphomas that one encounters during practice. I think you will see enough CLLs, Follicular lymphomas and classic Hodgkin lymphomas to be well versed in the morphologies of these items. More rare lymphomas should probably get their own due with a separate atlas dedicated to the variety and complexity of lymphomas.
List of cases in this atlasClick on the appropriate letter tab above to see the case images
- Angiomyomatous hamartoma
- Bacillary angiomatosis
- Burkitt lymphoma
- Castleman disease
- Dermatopathic lymphadenopathy
- Dilatin lymphadenopathy
- EBV lymphadenitis
- Fujimoto-Kikuchi lymphadenitis
- Gaucher disease
- Herpes lymphadenitis
- Immunodeficiency (HIV) lymphadenitis
- Immunodeficiency (Congenital) lymphadenopathy
- Jirovecii Pneumocystis lymphadenitis
- Kawasaki disease
- Kimura lymphadenopathy
- Kaposi sarcoma involving lymph nodes
- Lepromatous leprosy
- Mastocytosis involving lymph nodes
- Nodular lymphocyte predominant Hodgkin lymphoma
- Old man's groin lymph node changes
- Proteinaceous lymphadenopathy
- Progressive transformation of germinal centers
- Qunisy (aka peritonsillar abscess
- Rosai-Dorfman lymphadenopathy
- Toxoplasma lymphadenitis
- Vascular transformation of lymph node sinuses
- Visceral larva migrans (Toxocara)
- Whipple lymphadenitis
- Yersinia lymphadenitis
Angiomyomatous hamartoma => Usually incidentally enlarged inguinal node in young males ... Typified by the presence of bands of smooth muscle reaching to edge of cortex +/- hilar fat.
Amyloidosis => Look in nodes from patients with marginal zone lymphoma, lymphoplasmacytic lymphoma or plasma cell neoplasms
Bacillary Angiomatosis => Less common in developed countries with wider availability of HAART HIV therapy, but still present in HIV endemic areas.
Burkitt Lymphoma => 90% will have identifyable MYC rearrangements, but MYC-neg cases occur and show classic histologic features. These may carry 11q aberrations. Immunohistochemistry with Bcl-2 & Tdt neg, MYC protein pos at high levels can help with the differential.
Castleman disease => Hyaline Vascular variant: common, usually localized, may cause unexplained anemia; Plasma cell Variant: can be multifocal, more aggressive, think HIV/HHV8 (or concommitant Kaposi sarcoma)
Dermatopathic lymphadenopathy => In Kids -> the differential diagnosis is w/ LCH (which unlike dermatopathic Langerhans cells, will be cyclinD1 neg). In Adults -> Always briefly consider mycosis fungoides or other T-cell lymphoma related dermatopathic change.
Dilantin adenopathy => Changes may simulate cat-scratch, Kikuchi or lymphoma ... But history of seizure disorder and timing with medication is key!
EBV lymphadenitis -> EBV ISH will be positive in a spectrum of variably sized B-cells, unlike in EBV-related lymphoma where, typically, all EBV pos B-cells are same size.
Fujimoto-Kikuchi lymphadenitis 😉 -> Similar histology with SLE adenitis. A MPO stain is neat way to highlight crescenteric histiocytes in KFH. This can be helpful to distingus proliferative Kikuchi disease from T-cell lymphomas. Beware not to overcall CD8+ T-cells as a T-lymphoproliferative disorder, these immunoblastic T-cell are enriched in KFD.
Gaucher's disease -> Classic combination of young age, failure to thrive and organomegaly in liver, spleen and nodes. Rare... but exciting when you catch it.
Herpes lymphadenitis -> Typical changes are punctate, neutrophilic abscesses with rare nuclear viral inclusions. Sometimes, isoalted herpes lymphadenitis can be seen as local reactivation in CLL nodes!
Immunodeficiency: HIV w/ follicle lysis -> Floird follicular hyperplasia + germ center hemorrhagic lysis. With right history, always 👀 for Kaposi or Toxoplasmosis changes in background.
Immunodeficiency: Congenital -> "Empty looking nodes" with few follicles +/- well devloped germinal centers, 🔼plasma cells & 🔽 T-cells. +/- Granulomas. Increased risk of lymphoma of various types.
Jirovecii (Pneumocystis) adenitis 😉-> Necrotizing granulomas, "bubbly" histiocytes, few neutrophils. Uniform size of organisms and absence of budding argues against Histoplasmosis
Kawasaki adenopathy: Rarely nodal disease with fevers is 1st presentation. Mottled node with microangiopathic vascular thrombus + ischemic changes.
Kimura disease: Benign inflammatory adenopathy with peripheral eosinophilia. Hyperplastic follicles + prominent vessels + eosinophils & polykaryocytes.
Kaposi sarcoma: HIV+ patients with HHV8 coinfection. I was once schooled by a Hungarian colleague that name is pronounced Kap-o-Shee, not kap-Oh-seeeee.
Leishmaniasis (Visceral): Can rarely find granulomas with intracellular "dots in spaces" pattern. Highlighted best with Giemsa stains on thinly sectioned slides or touch imprints fixed in EtOh.
Lepromatous leprosy: Prevalent in developing parts of the world. Highlighted in paraffin tissues or direct smears as weakly acid fast or, better yet, with Fite stain.
Mastocytosis: Lymph node involvement usually obaserved in systemic forms. Sometimes one can see concurrent marked 🔼 in eos. CD117/CD25+ phenotype, often with KIT-D816V mutation.
Nodular LP HL: CD20+ B-cell lymphoma with "mass in mass" pattern of nodal effacement and increased numbers of PD-1+ T-fh cells. Differential diagnosis includes: cHL and TCRLBCL Note the numerous variant patterns in this excellent reference 👇🏾!!!
Old Man Groin Node: Look, I did my best. Read all my lymph node books. Googled for an hour. This is the best I could come up with. Authoritative reference ?? 👇🏾
Progressive transformation of germinal centers -> Disruption of germinal centers by mantle zone lymphocytes. Despite historical suggestions otherwise, this is not precursor lesion to NLPHL. Importantly, it can explain persistent adenopathy.
Proteinaceous Lymph node -> Rare⚠. Extracellular nonamyloid Immunoglobulin deposits causing enlargement which can be associated with plasma cell dyscrasia or rheumatic diseases.
Quinsy (aka peritonsillar abscess 😏 --> Okay, I cheated a bit for this letter and used a tonsil. Take a peek for HSV on your next quinsy...you might be surprised to encounter innocent herpes infections.
Reference #1: https://www.ncbi.nlm.nih.gov/pubmed/17141448
Rosai-Dorfman disease (of course!) --> Dr. Dorfman once impressed upon me that if one doesn't see lots of plasma cells, don't make this diagnosis. Some extra-nodal forms can be tricky to identify. Recently, some studies show an association with IgG4 excess in a subset of Rosai-Dorfman disease.
Bonus content: See this nice obituary of Dr. Dorfman, indeed a giant figure in lymph node pathology
Sarcoidosis -> Tightly formed granulomas, usually without necrosis. Focal punctate necrosis can be seen on occasion. Be careful with GMS though, as pseudo-fungal yeast representing Hamazaki-Wesenberg bodies can be found!👇🏾
Toxoplasma adenitis -> Lymph node changes in 3 acts: 1) florid hyperplasia, 2) histiocyte clusters push germinal centers, and 3) monocytoid B-cell expansion. Serology + history is far more useful than Toxo IHC
Vascular transformation of lymph nodes -> Vasoproliferative lesion of lymph nodes that may explain persistent adenopathy and be associated with prior lymph node dissections.
Visceral larva migrans -> Toxocara larvae induced eosinophilic macroabscesses +/- Splendore-Hoeppli reaction. Similar changes with any metazoan larvae in nodes.
Whipple lymphadenopathy -> Characteristic low-power "lymphangiogram" pattern of open cystic spaces + granular histiocytes. Gram+/PasD+ organisms.
Yersinia lymphadenopathy -> Characteristic epithelioid necrotizing granulomas localized to the germinal centers. Mesentery and bowel lymph nodes are most commonly involved.
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