0521779407-01 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:45
30 Acute Lymphoblastic Leukemiaof some environmental exposures to chemical agents (e.g., pesti-
cides) may be important, but most cases not associated with defined
causative factor
Signs & Symptoms
■Most symptoms relate to bone marrow replacement with leukemia
(e.g., patients present with excessive fatigue, infection, fever, bruis-
ing, bleeding).
■Patients may also present with symptoms related to bulk disease (e.g.,
lymph node enlargement, splenic enlargement, pain) and rarely
shortness of breath with very high counts (leukostasis) or from bulk
disease in the chest (mediastinal mass, pleural effusions).
■Patients infrequently (∼3–5%) have symptoms from CNS involve-
ment at presentation (headache, confusion, cranial nerve involve-
ment); rare presentation may also include involvement of the orbit.
■A thorough history must be taken with a complete review of symp-
toms, exposure to drugs, environmental agents, and familial dis-
eases.
■Physical signs associated with bone marrow failure (e.g., pallor,
tachycardia, fever, petechiae, ecchymoses, infection)
■Physical signs associated with bulk disease (lymphadenopathy,
splenomegaly, hepatomegaly, pleuro/pericardial effusions, medi-
astinal mass)
■Complete physical examination critically important, including tes-
ticular examination (painless enlargement of a unilateral testis may
occur in a small percentage of male children [∼2%] or in patients
with T-cell leukemia or hyperleukocytosis), and a careful baseline
neurologic examination is important.
tests
Basic Blood Tests
■Review the peripheral blood smear for evidence of circulating imma-
ture cells (lymphoblasts), evidence of decreased platelets and lack of
mature normal peripheral blood cells. Consensus is that FAB distinc-
tion between L1 and L2 is not useful. ALL is currently classified more
on immunophenotype complemented by cytogenetic and molecu-
lar genetic subclassification. The major subclassifications are:
(1) Precursor B lymphoblastic leukemia characterized by expression
of CD19 and/or CD79a and/or CD22; subsets also include pro-
B-ALL with no additional differentiation markers; common (c-
ALL) additional expression CD10, and pre-B-ALL with cytoplas-
mic IgM.