Aka Lymphoid neoplasms, lymphomas a heterogenous group of neoplasms that arise in the lymphatic and reticuloendothelial (RE) systems.

Major types: Hodgkins & Non-Hodgkin's Lymphoma (NHL)

HODGKIN'S DISEASE
--RSC = Reed Sternberg Cells (diagnostic)
--S/Sx: presents as nontender nodal enlargement (over > 2cm, local or generalized)(70% first in cervical/supraclavicular chains, 20% first in axillary nodes, 10% first in inguinal nodes)
--S/Sx: PAIN w/ alcohol comsumption: in affected NODES!!
--S/Sx: fever, night sweats, intense pruritis is an early sign
--S/Sx: Pel-Ebstin fever: a few days of high fever reg alt w/ weeks of normal/subnormal temp
--STAGES: I & II: no systemic Sx (90% cure), III & IV: disseminated (60-70% 5 yr survival)-->night sweats, wt loss, fever, intense pruritis
--Systemic SX: when mediastinal/retoperitoneal nodes, liver, or bone marrow involved
--PROG: long term survivors at risk for 2nd cancer: myelodysplastic syndromes, AML and lung cancer mostly, but also NHL, breast and gastric cancer, melanoma
--Dx: lymph node biopsy shows REED-STERNBERG CELLS with non-neoplastic inflammatory cells (lymphs, plasma cells, EOS, etc) (double cell reminds me of the appearance of giardia--it's looking at you)
--slight to moderate neutrophilia
--lymphocytopenia can occur early and become more pronounced with progressing dz
--EOS high in 20%
--thrombocytosis mb present
--ESR and LAP increase --> active dz
--microcytic hypochromic anemia in advanced dz
--DISTRIBUTION: bimodal, peaks at age 15-34 and after age 60
--spreads to CONTIGUOUS LN's
--ETIO: unknown, two studies show genetic component
--ETIO: Hx of EBV, HIV, woodworking as occupation
--ETIO: 2 factors in transformation of HL:
1) EBV episomes have LMP-1-->signals upreg of NFkappaB-->transcription factor that activates cell and stops apoptosis
2) RSC's secrete IL-5, IL6, IL-13, TNF and GM-CSF which increases all reactive cells.
--WHO recognizes 5 subtypes:
1) nodular sclerosis (lacunar has multilobate or delicate folded nucl w/ abundant pale cytoplasm) (first four all show: large cell w/ multiple nuclei or single nucleus w/ multi lobes containing inclusion cysts, abundant cytoplasm)
2) mixed cellularity (mononucluear cell type) (single round or oblong nucleus w/ Ig inclusion like nucleolus)
3) lymphocyte-rich
4) lymphocyte depletion
5) lymphocyte predominance (different phenotype than the other four, which are consider classical forms)(L & H cells have polyploid nuclei that look like popcorn kernels)

NHL = NON-HODGKIN'S LYMPHOMA
--2/3 present as nontender nodal enlargement, 1/3 arise at extranodal sites (skin, bone, stomach, brain, oral & nasal pharynx, tonsils, salivary glands, thyroid, testes, breast)
--clonal prolif of lymphoid cells in LN's, marrow, tonsils, spleen, liver or GI
--Waldeyer ring and mesenteric nodes commonly involved
--more involvement of multiple peripheral nodes (noncontiguous spread)
--ETIO: dunno, mbdt HTLV-1
--50% more in males, mb attrib to chem exposure
--over 80% are of B cell origin, 10-20% of T cell origin in west
--80% of pts have generalized dz making staging difficult
--anemia present in 33% initially, most develop it as dz progresses
--NON-CONTIGUOUS SPREAD
--leukemic phase in 20-40% of cases
--DX: LN biopsy
--PREVENTion: NHL risk inversely assoc w/ increasing weekly servings of all veggies
--Prevent: green tea increases apoptosis of epithelial and tumor cells in animal studies
--arises in small lymphoid sites
--does NOT have Reed-Sternberg cells

WALDEYER'S RING = circle of lymphoid tissue at upper ends fo resp and alimentary tracts, incl: pharyngeal tonsil (adenoid), tubal tonsil, palatine tonsil, lingual tonsil, palatine tonsil, tubal tonsil, back to pharyngeal.

BURKITT'S LYMPHOMA
--highly undifferentiated B cell lymphoma
--most tumors extranodal: LN's and RE system (anywhere in circ)
--most common in Central AFRICA
--mostly in children/young adults
--30% of NHLs in US
--ETIO: assoc w/ hx of EBV infx**
--3 categories: 1) African 2) Sporadic (nonendemic) 3) Subset of aggressive lymphomas in HIV
--intermediate sized lymphoid cells, STARRY SKY PATTERN* in LN
--*translocation of gene c=MYC on xsome 8
--all endemic tumors latently infx w/ EBV, infx precedes transformation
--endemic presents as mass in MANDIBLE and in abdominal viscera (kidney, ovary, adrenal)
--sporadic BL oft presents in ileocecum or peritoneum with large abdominal mass
--involvement of marrow and blood is rare
--in general is aggressive cancer that response well to high dose, short term chemo

SLL = Smally Lymphocytic Lymphoma, see CLL in Leukemia post

FOLLICULAR LYMPHOMA
--*genetic translocation --> overexpression of *BCL2* protein, apoptosis antagonist (90%)
--most common form of NHL, nodular, lymphocytosis in 10%
--less proliferative and aggressive than diffuse lymphomas
--30-50% transform to diffuse large B-cell lymphoma with survival under 1 year (sim to CLL)
--45% of adult lymphomas in US, incurable, waxing/waning course, 7-9 year survival
--onset in middle age, M=F
--splenic white pulp & hepatic triads freq involved-
--S/Sx: painless, generalized LA
--two cell types:
----centrocytes, more common (small cleaved cell w/ irreg nucl, scant cytoplasm)
----centroblasts (larger cell, loose nuclear chromatin, nucloeli, modest cytoplasm)

DLBCL = DIFFUSE LARGE B-CELL LYMPHOMA
--only 20% of all NHL: DEADLY
--*dysreg of *BCL6* gene
--60-70% of aggressive lymphoid neoplasms
--median age 60, also is 5% of childhood lymphomas
--large size lymphocyte w/ multi nuclei, abundant and pale or basophilic cytoplasm
--two subtypes: immunodeficiency (in end stage HIV infx when EBV gets in tumor) and body cavity lg cell (in advanced HIV, presents as pleural or ascitis effusion, tumor cells infx w/ KSHV/HHV8)
--S/Sx: rapidly enlarging, oft symptomatic, single nodal or extranodal site (GI, skin, bone, brain), Waldeyer ring (esp tonsils & adenoids), masses in liver, spleen, BM involved late
--PROG: aggressive tumors are fatal if untx
--PROG: intensive chemo-->remission in 60-80%, may remain dz free for several years

FROM PATHOLOGY: 12 TYPES OF PERIPHERAL B-CELL NEOPLASMS
1) chronic lymphocytic leukemia/small lymphocytic lymphoma
2) B-cell prolymyphocytic leukemia
3) lymphoplastmacytic lymphoma
4) splenic and nodal marginal zone lymphoma
5) extranodal marginal zone lymphoma
6) mantle cell lymphoma
7) follicular lymphoma
8) marginal zone lymphoma
9) hairy cell lymphoma
10) plasmacytoma/plasma cell myeloma
11) diffuse large B-cell lymphoma
12) Burkitt lymphoma
(Most of these are considered NHL, non-Hodgkins. Plasma cell neoplasms are multiple myeloma, classic. Subclassic is hairy cell.)

ASSORTED T-CELL AND NK CELL NEOPLASMS

PERIPHERAL T-CELL LYMPHOMA
--an "eosinophil zebra": high EOS in an Asian, -->???
--T-cell tumors are 15% of NHL's in US and Eur, but are significantly more common in ASIA
--NK tumors are rare in the western world but more common in the FAR EAST.
(WHY????)
--tumors diffuse in lymph sys, mixed sizes of malignant T cells
--prominent angiogenesis
--EOS and macrophages ("reactive cells") attracted by T cell cytokines
--Dx: immunophenotyping
--S/Sx: generalized LAD, pruritis, fever, wt loss, eosinophilia on CBC
--PROGNOSIS: poor

ADULT T-CELL LEUKEMIA/LYMPHOMA
--neoplasm in pts infected with human T-cell leukemia virus type 1 (HTLV-1)
--most frequent in Japan, West Africa, and the Carribean basin
--S/Sx: skin lesion, generalized LAD, hepatosplenomegaly
--LABS: lymphocytosis, hypercalcemia
--tumor cells w/ multiilobulated nuclei called "cloverleaf" or "flower" cells in involved tissues and PB
--PROGnosis: terrible (fatal in months-1 year)

MYCOSIS FUNGOIDES / SEZARY SYNDROME / CUTANEOUS T-CELL LYMPHOMA
--tumor of CD4+ helper T cells
--mostly involves the SKIN
--3 stages of lesions: premycotic (inflam)-->plaque-->tumor.
--Sezary syndrome is a leukemic variant of mycosis fungoides
--skin involvement: generalized exfoliative erythroderma
--"indolent" tumors with 8-9 year median survival, less than 3 yrs after dx
--transformation to LARGE CELL LYMPOMA OF T-CELL TYPE is occasionally the terminal event

LARGE GRANULAR LYMPHOCYTIC LEUKEMIA = LGL
--rare, occurs in adults
--can be T-cell (indolent) or NK (aggressive) in origin
--LABS: hallmark: lymphocytes in blood and bone marrow with abundant blue cytoplasm containing scattered coarse "azurophilic granules"
--LABS: neutropenia, anemia

EXTRANODAL NK/T-CELL LYMPHOMA
--rare in US and EUR but up to 3% of NHLs in Asia
--commonly presents in NASOPHARYNX
--less in skin, testis
--tumor cells surround and invade small vessels, leading to extensive ischemic necrosis
--tumor cells have mostly large lymphoid cells w/ large AZUROPHILIC GRANULES