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Chapter 12: Leukaemia and lymphoma 485

Splenectomy may be required if the enlarged spleen

Leukaemia and lymphoma
is painful or to reduce transfusion requirements.
Acute leukaemia
Prognosis
The median survival of patients with myelofibrosis is
Acute lymphoblastic leukaemia (ALL)
3–6 years. Ten to twenty per cent of patients develop
acute myeloid leukaemia. Definition
Clonal proliferation of lymphoid progenitor cells.
Essential thrombocythaemia Incidence
85% of all childhood leukaemias.
Definition
Amyeloproliferative disorder characterised by increased
platelets due to clonal proliferation of megakaryocytes Age
in the bone marrow. Predominantly seen in childhood with a peak incidence
at 5 years. In adults incidence increases with advancing
age.
Pathophysiology
Platelets although increased in number have disrupted
Sex
function causing them to clump intravascularly lead-
M = F
ing to thrombosis, and to fail to aggregate causing
bleeding.
Aetiology
ALL is more common in Down’s syndrome and in syn-
Clinical features dromes involving chromosomal instability like Fanconi
Essential thrombocythaemia presents with bruising, anaemia. Risk factors include exposure to excessive ra-
bleeding and cerebrovascular symptoms. Initially there diation and benzene.
is splenomegaly but recurrent splenic thromboses lead
to a small atrophic spleen. Pathophysiology
In acute leukaemias there is replacement of the normal
bone marrow progenitor cells by blast cells, resulting in
Investigations
The blood film shows increased numbers of platelets and marrow failure. Acute lymphoblastic leukaemia arises
giant platelets. Bone marrow aspiration demonstrates from the lymphoid side of the haemopoetic system (see
increased megakaryocytes. Fig. 12.10). It can be subdivided into:
Common ALL arising from the common progenitors.
Pre B/B cell ALL.
Management
Pre T/T cell ALL (50% present with a thymic mass).
Mild disease may be treated with long term aspirin.
The blast cells of ALL tend to form reservoirs within the
Patients with a higher risk of thrombosis are treated
testes and CNS.
with hydroxyurea. Patients with life-threatening haem-
orrhagic or thrombotic events should be treated with
Clinical features
thrombocytopheresis in addition to hydroxyurea. An-
Often there is an insidious onset of anorexia, malaise
grelide is occasionally used.
and lethargy due to anaemia. There is often a history of
recurrent infections and/or easy bruising and mucosal
Prognosis bleeding. Other presentations include lymph node en-
Essential thrombocythaemia may eventually transform largement, bone and joint pain and symptoms of raised
to myelofibrosis or acute leukaemia but the disease may intra cranial pressure. On examination there may be pal-
not progress for many years. lor, bruising, hepatosplenomegaly, lymphadenopathy,