Pathologies Flashcards
Essential Thrombocytosis
Pathogenesis: Neoplastic proliferation of mature myeloid cells, mostly plateletsGenetics: JAK2 mutation Clinical Presentation: Increased risk of thrombosis*no risk of gout
Mastocytosis
Pathogenesis: Neoplasm of mast cellsGenetics: activating c-KIT mutation, CD117+, tryptase+Clinical Presentation: Urticaria pigmentosa or systemic mastocytosisHisto: Increased morphologically abnormal mast cells in various tissuesLabs: + metachromatic stains (toluidine blue)
Acute Myeloid Leukemia (AML)
Pathogenesis: Proliferation of myeloid cells without maturation (blasts/precursors)Genetics: t(15;17), t(8;21), inv(16), or 11q23 abn, Monosomy 7Clinical Presentation: Anemia (weakness, fatigue, pallor), Thrombocytopenia (bleeding), HepatosplenomegalyHisto: Blasts and Auer rodsLabs: Sudan black B+, MPO+, TdT-, CD34+*20% of all leukemias and 85% of adult leukemias
Acute Promyelocytic Leukemia (PML)
Pathogenesis: Type of AML. Proliferation of myeloid cells without maturation (blasts/precursors)Genetics: t(15;17). This disrupts retinoic acid receptor (RARα) geneClinical Presentation: Frequently associated with DICHisto: Abnormal promyelocytes with multiple Auer rodsLabs: Sudan black B+, MPO+, TdT-, CD34+Tx: ATRA
Acute Myelomonocytic Leukemia
Pathogenesis: Type of AML. Proliferation of myeloid cells without maturation (blasts/precursors)Genetics: inv(16) or t(16;16)Clinical Presentation: Anemia (weakness, fatigue, pallor), Thrombocytopenia (bleeding), Hepatosplenomegaly. Usually infiltrate the gumsHisto: Abnormal promyelocytes with multiple Auer rodsLabs: Sudan black B+, MPO-, TdT-, CD34+
Myelodysplastic Syndrome
Pathogenesis: Ineffective hematopoiesisGenetics: Monosomy 7Clinical Presentation: Peripheral cytopenia and Hypercellular BMHisto: Ringed sideroblasts, hypo-lobated neutrophils, and macrocytic anemia
Langerhans Cell Histiocytosis
Pathogenesis: neoplastic proliferation of Langerhans cellsHisto: Birbeck granules, admixed eosinophils, plasma cells, and neutrophilsSubtypes: Eosinophlic granuloma, Hand-Schuller-Christian Disease, Letterer-Siwe Disease
Eosinophilic Granuloma
Pathogenesis: Neoplastic proliferation of Langerhans cellsHisto: Birbeck granules, admixed eosinophils, plasma cells, and neutrophilsClinical Features: Bone pain, lung nodules M:F = 4:1,5-30 y.o.Prognosis: Self limited
Hand-Schuller-Christian DIsease
Pathogenesis: Neoplastic proliferation of Langerhans cellsHisto: Birbeck granules, admixed eosinophils, plasma cells, and neutrophilsClinical Features: Diabetes insipidus, membranous bone defects, proptosis M:F = 1:1 2-5 y.o.Prognosis: indolent
Letterer-Siwe Disease
Pathogenesis: Neoplastic proliferation of Langerhans cellsHisto: Birbeck granules, admixed eosinophils, plasma cells, and neutrophilsClinical Features: Dermatitis, organomegaly M:F = 1:1, < 2 y.o.Prognosis: Poor
Acute Lymphocytic Leukemia/Lymphoblastic Lymphoma (ALL)
Pathogenesis: Accumulation of lymphoblasts in the blood and bone marrow. 85% are B cell type. Neoplasm of lymphoid stem cell (lymphoblast)Genetics: Hyperdiploidy is a favorable prognosis, t(4;11) and/or t(9;22) is a bad prognosis, t(12;21) is a favorable prognosisImmunophenotype: TdT+, sIg- (no surface immunoglobulin), CD10+, CD29+Clinical Presentation: Bone pain, anemia*most common malignancy of childhood
Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia (CLL)
Pathogenesis: Accumulation of mature B-lymphocytesGenetics:mutated (7 years) > unmutated (3 years)Immunophenotype: CD5+, CD19+, CD20+, sIg+Clinical Presentation: Asymptomatic, anemia, thrombocytopenia, lymphadenopathy, lymphocytosisLymph Node: diffuse infiltrate of small, round lymphocytesHisto: Smudge cellsComplications: Richter transformation to diffuse large B-cell lymphomain 5-10%, Autoimmune Hemolytic Anemia, Hypogammaglobulinemia*most common leukemia in the US, seen in older adults
Hairy Cell Leukemia
Pathogenesis: Mature B-lymphocytes with villous cytoplasmic projectionsClinical Presentation: Hepatosplenomegaly (red pulp), Pancytopenia, InfectionsGenetics: BRAF mutationImmunophenotype:CD11c+, CD25+, CD103+, Annexin A1+, TRAP+Histo: “Hairy cells” - lymphocytes with villous cytoplasmic projections. Absolute monocytopeniaBone Marrow: Increased retculin fibrosis
Follicular Lymphoma
Pathogenesis: Neoplastic proliferation of small B cellsClinical Features: Generalized lymphadenopathy and hepatosplenomegalyGenetics: t(14;18) leading to overexpression of Bcl-2 which prevents apoptosisImmunophenotype: CD19+, CD20+, CD10+, CD5-, sIg+Lymph node: Nodular infiltrate of small, cleaved lymphocytes with admixed large cells. Markedly diminished/absent mantle zones*very common lymphoma in the US
Diffuse Large B-Cell Lymphoma
Pathogenesis: Neoplastic proliferation of large B cells that grow diffusely in sheetsGenetics: some cases associated with EBV and KSHV/HHV8Immunophenotype: CD19+, CD20+, CD10+/-, CD5-, sIg+Lymph Node: diffuse infiltrate of large, non-cleaved lymphocytes*most common lymphoma in the US
Plasma Cell Myeloma (Multiple Myeloma)
Pathogenesis: Multifocal destructive infiltration of plasma cells in the bone marrowClinical Features: Punched out bone lesions, Hypercalcemia, Renal disease, Anemia, Primary AmyloidosisBlood: Monoclonal (M) Ig or light chain spike on SPEP/UPEP, Rouleaux formation on blood smear, Increased IL-6Bone Marrow: Nodules or diffuse sheets of plasma cellsUrine: Bence Jones protein (monoclonal free light chain)
Solitary Osseous Plasmacytoma
Pathogenesis: Neoplasm of terminally differentiated, Ig secreting B lymphocytes. Plasma cell proliferation and M componentClinical Features: Single destructive bone lesion
Extraosseous Plasmacytoma
Pathogenesis: Neoplasm of terminally differentiatied, Ig secreting B lymphocytes. Plasma cell proliferation and M componentClinical Features: Extramedullary soft tissue mass
Monoclonal Gammopathy of Undetermined Significance (MGUS)
Pathogenesis: Increased serum protein w/ M spike on SPEP/UPEP but other features of multiple myeloma are absent* commonly in elderly* 1% of pts. w/ MGUS develop multiple myeoma each year
Waldenstrom Macroglobulinemia
Pathogenesis: B-cell lymphoma with monoclonal IgM productionClinical Features: Generalized LAD (lytic bone lesions absent), increase serum protein w/ M spike on SPEP/UPEP, visual and neurologic deficits (b/c of stroke/hemorrhage from increased viscocity of blood)Tx: plasmapheresis and/or Ibrutinib
Heavy Chain Disease
Heavy chains produced withought light chains
Burkitt Lymphoma/Leukemia
Pathogenesis: Neoplastic proliferation of intermediate-sized B cellsGenetics: Associated with EBV,t(8;14), c-MYC oncogene translocated to Ig heavy chain locusImmunophenotype: CD19+, CD20+, CD10+, CD5-, sIg+, TdT-Clinical Features: Classically presents as an extranodal mass in a child or YA (African = jaw Sporadic = abdomen)Lymph Node: DIffuse infiltrate of medium-sized, non-cleaved lymphocytes. Tingible body macrophages present = “starry sky pattern”
Mantle Cell Lymphoma
Pathogenesis: Neoplastic proliferation of small B cells that expands the mantle zoneClinical Features: Presents in late adulthood w/ painless LAD. Most are advanced stage and have BM involvementGenetics: t(11;14)(q13;q32) in 70-75% of casesImmunophenotype: CD19+, CD20+, CD10-, CD5+, sIg+, CyclinD1+
Extranodal Marginal Zone B-Cell Lymphoma of MALT tissue
Pathogenesis: Neoplastic proliferation of small B cells that expands the marginal zone (post-germinal center B cells)Clinical Features: GI tract, lumg, head and neck, eye skin. Associated w/ chronic infection (H. pylori) and AI disorders (Hasimoto’s thyroiditis, Sjogrens, etc.)Tx: remove infection