Case 15 – summary

Paediatric ALL

In this case, our child presented with a petechial rash.  This can present with a number of different diagnosis therefore a wide differential needs to be formed.  This includes:

  • HSP – Usually a classical distribution of purpura, bruising and urticaria on the buttocks and extensor surfaces of the limbs, sometimes associated with joint or abdominal pain
  • ITP – Usually well children with multiple bruises and petechiae noted over several days
  • Acute Leukaemia – Symptoms of slower onset associated with anaemia, lymphadenopathy or hepatosplenomegaly
  • HUS – Oliguria/anuria associated with anaemia, usually following a diarrhoeal illness

Other possibilities:

•              Meningococcal disease (MCD)

•              Sepsis with other bacteria (uncommon)

•              Viral illnesses

•              Trauma//NAI

•              Mechanical e.g. due to raised intrathoracic pressure from coughing or vomiting in

superior vena caval distribution (above nipple line)

The blood count makes you suspicious, given the significant thrombocytopenia.  Blood film is the essential part of this film – However 20% of leukemic patients present with no evidence of blasts in the peripheral blood – therefore bone marrow biopsy is essential.

Image

This film shows classic findings in ALL leukaemia – including the mirror-handle cell!

Other symptoms of ALL:

  • Fever.
  • Easy bruising or bleeding.
  • Bone or joint pain.
  • Painless lumps in the neck, underarm, stomach, or groin.
  • Pain or feeling of fullness below the ribs.
  • Weakness, feeling tired, or looking pale.
  • Loss of appetite.
  • Testicular involvement

Other presenting signs can depend upon the type of ALL:

  • Patients with B-precursor ALL: Bone pain, arthritis, limping; fevers (low or high); neutropenia; fatigue, pallor, petechiae, and bleeding; lymphadenopathy and hepatosplenomegaly
  • Patients with mature-B ALL: Extramedullary masses in the abdomen or head/neck; CNS involvement (eg, headache, vomiting, lethargy, nuchal rigidity)
  • Patients with T-lineage ALL: Respiratory distress/stridor due to a mediastinal mass

In acute lymphoblastic leukemia (ALL), a lymphoid progenitor cell becomes genetically altered and subsequently undergoes dysregulated proliferation, with clonal expansion.

The child is at risk of tumour lysis, and therefore hydration and allopurinol is appropriate, and monitoring of electrolytes.

B-cell ALL

The cell markers confirm common B-all.

B-lineage ALL accounts for 80% of childhood ALL and involves lymphoblasts that have cell-surface expression of 2 or more B-lineage–associated antigens

  • ie, CD19, CD20, CD24, CD22, CD21, or CD79).
  • CD10 is commonly expressed, which makes it a useful diagnostic marker.
  • The presence of aberrant myeloid markers (eg, CD7) is occasionally noted but has little prognostic impact.
  • B-cell precursors of ALL can be further subclassified as early pre–B-cell, pre–B-cell, or transitional pre–B-cell, but distinguishing these subtypes is usually not clinically relevant.

Cytogenetics

Of the many abnormalities described,

  • Favourble prognosis: t(12;21)(p13;q22) or ETV6-RUNX1 (formerly known as TEL-AML1) and hyperdiploidy (>50 chromosomes/cell).  Trisomy 4, trisomy 10, and trisomy 17 (”triple trisomy”) may be seen in some hyperdiploid cells and share the favorable outcome.
  • Poor prognosis: Hypodiploidy (< 44 chromosomes/cell), t(4;11)(q21;q23) MLL-AF4 or MLL gene rearrangement, and t(9;22)(q34;q11), or Philadelphia chromosome positivity.

 

MRD

Monitoring MRD status has been shown to have a much higher sensitivity than that of morphology.  As a result current trial protocols use MRD status for risk assignment

Trials

In the UK, the current trial is UKALL2011.  This applies to patients between the age of 1 and 25, with a 1st diagnosis of ALL.  Patients are allocated treatment regime depending upon age and WCC.  4

Initially they are allocated to regimen A or B.

A – WCC<50, and age <10yrs, or patient with downs syndrome.  3 drug induction with dexamethasone, vincristine and asparaginase.

B – WCC>50, AND/OR age >10yrs, T-ALL, or lympohoblastic lymphoma.  4 drug induction with dexamethasone, vincristine, asparaginase and daunorubicin.

Patient may then be transferred to Regimen C based on MRD assessment on day 29.  Or earlier if cytogenetic show high risk features,

In general, boys receive 3 yrs of treatment, girls receive 2yrs.

About TeamHaem

Online education and discussion about all things haematological
This entry was posted in Acute leukaemia, Laboratory morphology, Paediatric haematology and tagged , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s