Haematology Vignettes – 20

A case of Burkitt cell leukaemia in a sixteen year old male

A 16-year-old male presented to the paediatric casualty department with a mass on the left-hand side of his face. He was otherwise feeling well. A full blood count was performed with the following results:
Hb 107 g/L, WBC 10.2 x 109/L and platelet count 53 x 109/L.

The blood film showed a leucoerythroblastic blood picture with 2% myelocytes, 54% blasts and 2 NRBC’s / 100 WBC’s. The red cells showed the presence of teardrop poikilocytes.

A bone marrow biopsy was performed. It was hypercellular with 80% blast cells. The blasts were medium in size, containing round nuclei with a fine chromatin pattern and nucleoli. The cytoplasm was deeply basophilic and contained many lipid-containing vacuoles.

Flow cytometry and cytogenetics were performed on the bone marrow sample with the following results:

Immunophenotype: TdT, HLA-DR, SIg+, CD5, CD10+, CD19+, CD20+, CD22+, CD23 and CD34

Cytogenetics: t(8;14)(q24;q32).

A diagnosis of Burkitt cell leukaemia was made on this young male.

Bone Marrow

Bone Marrow

Burkitt lymphoma/leukaemia is classified under mature B-cell neoplasms by the World Health Organization (WHO). Burkitt lymphoma is a highly aggressive lymphoma, often occurring at extra-nodal sites. It is referred to as Burkitt cell leukaemia when the bone marrow is involved.

There are three clinical variants of Burkitt cell lymphoma:

Endemic Burkitt cell lymphoma: this variant occurs in equatorial Africa and Papua New Guinea. It is the most common malignancy of childhood occurring in children between the age of four and seven years.

Sporadic Burkitt lymphoma: this variant occurs throughout the world. Occurring mainly in children and young adults, it is associated with the Epstein Barr virus (EBV).

Immunodeficiency associated Burkitt lymphoma: this variant is primarily associated with the human immunodeficiency virus (HIV).

Clinical presentation:
The clinical presentation varies according to the particular variant. The majority of patients with the sporadic variant present with an abdominal mass while those with the immunodeficiency associated variant present with nodal and bone marrow involvement.

All three variants may be associated with central nervous system disease (CNS).

The blast cells of Burkitt lymphoma are B cells expressing CD19, CD20, and CD22. Unlike the blasts of precursor B-cell acute lymphoblastic leukaemia, they are mature cells; they are TdT and CD34 negative.

The variants of Burkitt lymphoma are associated with a t(8;22)(q24;q11) and a t(2;8)(p12;q24).

Although highly aggressive, the endemic and sporadic variants are potentially curable. Treatment should be commenced as soon as possible after diagnosis due to the short doubling time of the tumour.

Treatment of Burkitt cell leukaemia involves intensive chemotherapy.

CNS involvement is often a complication of the disease.

Three months post commencement of treatment, the above patient presented with CNS disease. His CSF was heavily infiltrated with leukaemic blast cells. He died some weeks later.