Page 239 - Essential Haematology
P. 239

Chapter 17  Acute lymphoblastic leukaemia  /  225



























                      (a)                                        (b)


                                Figure 17.1   Acute lymphoblastic leukaemia.  (a)  Marked cervical lymphadenopathy in a boy.  (b)  Testicular
                      swelling and erythema on the left - hand side of the scrotum caused by testicular infi ltration.  (Courtesy of
                      Professor J.M. Chessels.)


                      syndrome (headache, nausea and vomiting, blurring

                                                                      Table 17.2   Specialized tests for acute
                      of vision and diplopia). Fundal examination may
                                                                  lymphoblastic leukaemia (ALL).
                      reveal papilloedema and sometimes haemorrhage.
                      Many patients have a fever which usually resolves         Cytochemistry
                      after starting chemotherapy. Less common manifes-      Myeloperoxidase           −
                      tations include testicular swelling (Fig.  17.1 b)       Sudan black          −
                      or signs of mediastinal compression in  T - ALL       Non - specifi c esterase          −
                      (Fig.  17.2 ).                                  Periodic acid – Schiff           +  (coarse block
                          If lymph node or solid extranodal masses pre-              positivity in ALL)
                      dominate with  < 20% blasts in the marrow the       Acid phosphatase          +  in T - ALL (Golgi
                      disease is called lymphoblastic lymphoma but is                staining)
                      treated as ALL.                                   Immunoglobulin and       B - ALL: clonal
                                                                  TCR genes          rearrangement of
                          Investigations                                             immunoglobulin genes
                                                                                      T - ALL: clonal
                       Haematological investigations reveal a normochro-             rearrangement of TCR
                      mic normocytic anaemia with thrombocytopenia in                genes

                      most cases. The total white cell count may be         Chromosomes and       (Table  17.1 )


                                                         9


                      decreased, normal or increased to 200  ×    10  /L or   genetic analysis

                      more. The blood film typically shows a variable

                                                                        Immunological markers   (Table  17.3 )





                      numbers of blast cells. The bone marrow is hyper-
                                                                  (fl ow cytometry)

                      cellular with  > 20% leukaemic blasts. The blast cells
                      are characterized by morphology (Fig.  17.3 ),
                                                                        B - ALL, B - cell acute lymphoblastic leukaemia; T - ALL, T - cell
                      cytochemisty (Table  17.2 ), immunological tests
                                                                  acute lymphoblastic leukaemia; TCR, T - cell receptor.
                      (Table  17.3 ) and cytogenetic analysis (Table  17.1 ).
   234   235   236   237   238   239   240   241   242   243   244