Lymphocytosis and lymphoid leukemias Flashcards
lymphocytosis
Absolute lymphocyte count >4000 / ul
Reactive increases in lymphocytes are transient
Neoplastic proliferations are chronic (persisting for >6 months)
Reactive expansions generally do not exceed 10k/ uL in adults (in kids they may have a high one)
Neoplastic lymphocytoses can cause extremely elevated WBC counts
Reactive expansions usually have heterogenous appearing lymphocytes (that can vary in size and cytoplasm, neoplastic proliferations have monotonous appearing lymphocytes
Reactive lymphocytosis
-Several conditions are associated with lymphocytoses.
-Most commonly due to infectious and transient stress lymphocytoses
Infectious mononucleosis (caused by epstein barr virus is a classic example), other things that can cause reactive lymphocytosis can be CMV, hepatitis, varicella, adenovirus, toxoplasmosis, and pertussis
Transient stress lymphocytosis may be the most common cause, usually seen with trauma, MI, seizures, and rapidly reverse within hours
Infectious mononucleosis
EBV infection that results in a lymphocytic leukocytosis compromised of reactive CD8+ T cells, CMV occasionally causes it–> saliva disease
EBV primarily infects oropharynx (pharyngitis), liver (hepatitis with hepatomegaly and increased liver enzymes), B cells
CD8+ T cell response leads to generalized lymphadenopathy due to T cell hyperplasia in the lymph node paracortex, Splenomegaly due to T cell hyperplasia in the PALS, High WBC count with a typical lymphocytes (in blood reactive CD8 T cells)
The lymphocytes are heterogenous, large and have abundant, lighlty basophilic cytoplasm, which hugs the neoghboring RBC (>50% mononuclear cells, marked lymphocytic heterogeneitiy, >10 % reactive lymphocytes)
Monospot test
Used for screening in mono
Detects IgM antibodies that cross react with hoarse or sheep RBC (heterophile Ab)
Usually turns postitive within a week after infection
A negative monospot test could be a result of CMV,
Definitive diagnosis is made by serology
neoplastic lymphocytosis
Neoplastic proliferations of mature lymphocytes include: Chronic lymphocytic leukemia, hairy cell leukemia, splenic marginal zone lymphoma, large granular lymphocytic leukemia, adult T cell leukemia and sezary syndrome
Neoplasms will be clonal (via monoclonl light chain expression) - only lambda or kappa
Reactive would be polyclonal (lamda and kappa)
Neoplastic lymphoid cells involve the blood predominantyl are termed LYMPHOID LEUKEMIA
neoplasms in tissues- Lymphoma
Acute lymphoblastic leukemia/lymphoma
Neoplastic accumulation of lymphoblasts (>20%) in the bone marrow, kids are young, an Acute perosn is a oung person
Lymphoblasts are characterized by positive staining for TdT (a DNA polymerase), TdT is absent in in myeloid blasts and mature lymphocytes
Most common in children associated with Down syndrome (after 5 yo)
Sub classified into B and T - ALL
You cant mature youre precursor blasts–> mature WBC-> blasts built up up
B- ALL (b cell- acute lymphopblastic leukemia)
Precursor B cell in the bone marrow, predominantly children, symtoms relating to marrow replacement and pancytopenia
AGGRESSIVE
CD34 +, CD10 +, TdT +, CD 19 +,
CD20- !
Excelent response to chemotherapy, go to scrotum and CSF just in case
Good prgnosis: hyper diploidy, T12, 21
Bad prognosis: hypodiploidy, T9,22 (philidelphia chromosome0, 11 q 23 abnormalities
INOTUZUMAB
T- ALL (t cell acute lymphoblastic leukemia)
like a thymic mass in a teenager
CD2 throu cd8 dual +
TdT +
no CD10, - !
no prognosis differences
Mature aka chronic Lymphoid leukemias
chronic/mature B cell Leukemias:
- CLL/ SLL (chronic lymphocytic leukemia/ small lymphocytic lymphoma)
- hairy cell leukemia
Chronic/mature T cell leukemias:
- Adult T cell leukemia/lympnoma
- Mycoses fungoides/sezary syndrome
- Large granular lymphocytic leukemia
Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)
Neoplastic proliferation of naive B cells that co express CD5, CD19, CD20, CD23
Most common leukemia overall
Increased lymphocytes and smudge cells are seen on blood smear, lymphocytosis composed of small lymphs with round nuclei and soccor ball/ gingersnap chromatin
Involvement of lymph nodes leads to generalized lymphadenopathy and is called SMALL LYMPHOCYTIC LYMPHOMA
Complications include: hypogammaglobunemia (infection a big cause of death), Autoimmune hemolytic anemia, Transformation to diffuse large B cell lymphoma
Older adults with bone marrow and lymph node disease, usually asymptomatic, autoimmune hemolysis, and thrombocytopenia
It is an indolent disease
Good prognosis: deletion of 13 q, mutated IgHV
Intermediate risk: Trisomy 12
Bad prognosis: Deletion 11q, Deletion 17 p, Unmutated IgHV
Hairy cell leukemia
neoplastic proliferation of mature B cells characterized by hairy cytoplasmic processes and reniform nuclei
Cells are positive for TRAP (tartrate resistant acid phosphatase)
40-60 yo males with pancytopenia, splenomegaly (due to accumulation of haircells in the red pulp), dry tap on bone marrow aspiration
An indolent disease, eccelent response to 2CDA an adenoside deaminase inhibitor (by adenosie accumulates to toxic levels in neoplastic B cells)
Trapped in the bone marrow, Trap in red pulp, and cant go to lymph node
CD 19, CD20, CD11, CD22, bright positive
Adult T cell leukemia lymphoma
Neoplastic proliferation of CD4+ T helper cell, CD25+
Associated with HTLV-1 most common in japan and caribbean
Adults with skin rash, hepatosplenomagaly, lymphadenopath, lytic bone lesions, Endemic in japan, west africa, and the caribbean due to HTLV prevalence
An aggressive disease
Flower cells. lymphocytes with lobulated nuclei, often lymphocytosis
Mycosis fungoides, Sezary syndrome
Neoplastic proliferation of mature CD4+ T cells that infiltrate the skin leading to rash, plaques and nodules, aggregates of neoplastic cells in the epidermis are called Pautrier microabcesses
Cells spreading to blood causes sezary syndrome–> lymphocytes with cerebriform (lobulated nuclei) on blood smear, powdary cromatin
Adult patiens with generalized erythema and lymphadenopathy, Sezary more aggressive,
T cell Large granular lymphocytic leukemia
proliferation of Cytotoxic CD8 + t cells
Adult patients with neutropenia, anemia, splenomegaly, may be associated with auto immune disease (rheumatoid arthritis
An indolent disease
Lymphocytes with eosinophilic granules
