Lymphoma

Question 1

B symptoms

Answer 1

lymphadenopathy, fever, night sweats, weight loss

Question 2

reactive lymphadenopathy: histologic patterns

Answer 2

follicular hyperplasia (B-cell expansion - autoimmune, early HIV, toxoplasmosis), paracortical hyperplasia (T-cell expansion - EBV, CMV, herpes, drugs), sinus histiocytosis (draining tumor), necrotizing (cat scratch fever, bacterial, fungal, viral, autoimmune), granulomatous (fungal, TB)

Question 3

follicular lymphoma

Answer 3

lineage: B-cell (may be T-cell in other countries)
immunophenotype: BCL2+ CD10+ CD19+ CD20+
genotype: t(14;18)
histology: pale, well-defined nodules with small cells; include all normal follicular cell types but lack polarization or other normal architecture; grading depends on number of centroblasts
presentation: middle-aged adults with generalized lymphadenopathy
progression: indolent, but may transform into Burkitt or DLBCL

Question 4

mantle cell lymphoma

Answer 4

lineage: B-cell (mature)
immunophenotype: CyclinD1+ CD5+ CD19+ CD20+
genotype: t(11;14)
histology: nodular architecture, variable cell size
presentation: older males, disseminated disease often involving GI tract
progression: moderately aggressive

Question 5

diffuse large B cell lymphoma

Answer 5

lineage: B-cell (mature)
immunophenotype: CD19+ CD20+
genotype: diverse chromosomal rearrangements
histology: large cells, diffuse architecture
presentation: most common in adults, rapidly-growing mass/lymphadenopathy
progression: aggressive

Question 6

Burkitt lymphoma

Answer 6

lineage: B-cell (mature)
immunophenotype: c-MYC+ CD10+ CD19+ CD20+
genotype: t(8;14), t(2;8), or t(8;22)
histology: “Starry sky” (background of dark tumor cells with light macrophages interspersed), large cells, diffuse architecture
presentation: adolescents/young adults with rapidly-growing ileocecal mass (sporadic), breast/jaw/ovarian mass (endemic, EBV-associated), or immunosuppressed pts (EBV-associated)
progression: aggressive

Question 7

Hodgkin lymphoma (classical)

Answer 7

lineage: B-cell
immunophenotype: CD15+ CD30+
genotype:
histology: Reed Sternberg cells (large, multi-lobated/multi-nucleated cells) in the background of reactive inflammatory cells, lacunar cells, nodules/sclerosis
presentation: adolescents and young adults with mediastinal or cervical lymphadenopathy; confined to lymph nodes, contiguous spread
progression: moderately aggressive

Question 8

extranodal NK/T cell lymphoma

Answer 8

lineage: NK or cytotoxic T-cell
immunophenotype:
genotype: no specific abnormalities
histology:
presentation: EBV-associated, adults with destructive extra nodal granulomatous masses (usually sinonasal)
progression: aggressive

Question 9

extranodal marginal zone lymphoma

Answer 9

lineage: B-cell
immunophenotype: CD19+ CD20+
genotype: t(11;18) (MALT1-IAP2 fusion gene)
histology:
presentation: localized to mucosa/epithelia, i.e. gastric, orbital, thyroid, lung lymphoid tissue; associated with chronic infection (Hashimoto’s thyroiditis, H. pylori), treated with excision/Abx
progression: indolent

Question 10

nodular lymphocyte-predominant Hodgkin lymphoma

Answer 10

lineage: B-cell
immunophenotype: CD20+ CD45+
genotype:
histology: small cells with nodular architecture, popcorn cells, L&H cells
presentation: middle-aged adults with cervical or axillary lymphadenopathy
progression: indolent

Question 11

anaplastic large-cell lymphoma

Answer 11

lineage: T-cell (CD4+)
immunophenotype: CD4+
genotype: t(2;5), ALK rearrangement
histology:
presentation: pediatric tumor
progression: aggressive (but responds well to chemotherapy)