Two cases of mature B-cell acute lymphocytic leukemia with normal karyotype in adults

Precursor B-cell lymphoblastic leukemia with surface immunoglobulin light chain expression in 2 chinese patients

BACKGROUND

Precursor B-cell acute lymphocytic leukemia (ALL) with surface immunoglobulin light chain expression is a rare disease entity. The differential diagnosis is difficult but critical for disease management.

AIMS

We report 2 cases (1 adult and 1 infant) of precursor B-cell ALL who presented at diagnosis with surface immunoglobulin light chain expression revealed by flow cytometric immunophenotyping and discuss its clinical significance.

CASE REPORT

The 2 patients presented with nonspecific symptoms such as fever, pallor, fatigue or lymphadenopathy. Flow cytometric immunophenotyping showed that both patients expressed CD34/CD19/CD10/CD22/CD9/HLA-DR/CD38/CD123/CD13 (partial) and had unexpected single λ light chain expression. Cytogenetic analysis revealed t(9;22)(q34;q11) in the adult patient and normal karyotype in the infant. Both cases were diagnosed and managed as precursor B-ALL, and the patients showed good response to treatment regimens.

CONCLUSION

We describe 2 cases of precursor B-ALL with unexpected surface light chain expression. The exceedingly rare immunophenotypes have diagnostic implication for immunophenotyping of this malignancy. Treatment regimens for precursor B-cell ALL are suitable for such cases.

Lymphoblastic Leukemia With Mature B-Cell Phenotype in Infancy

Lymphoblastic leukemias with surface immunoglobulin light chain expression and L1/L2 blast morphology (French-American-British Classification) are rare. The poor prognosis of lymphoblastic leukemia in children under 1 year of age is attributed largely to rearrangements involving the mixed lineage leukemia (mll, also known as all1, htrx, trx1, or hrx) gene that occur with increased frequency in this population. Mll-rearranged cases with a mature B-cell phenotype are rare. The authors describe an infant with mature B-cell lymphoblastic leukemia with an mll rearrangement and L1/L2 cytomorphology and discuss the clinical, genetic, and immunophenotypic features in the context of previously reported cases.

Mature B-cell acute lymphoblastic leukemia with t(9;11) translocation: a distinct subset of B-cell acute lymphoblastic leukemia

Mature B-cell acute lymphoblastic leukemia (ALL) is typically associated with the FAB-L3 morphology and rearrangement of the MYC gene, features characteristic of the leukemic phase of Burkitt's lymphoma. However, the term 'mature' has also been used to describe other rare cases of B-ALL with light-chain surface immunoglobulin expression. In contrast, infantile B-cell ALL is generally characterized by rearrangement of the MLL gene, an immature pro-B-cell phenotype, and CD10 negativity. We describe two unusual cases of infantile B-ALL with non-L3 morphology, expressing a mature B-cell phenotype (lambda sIg+, CD19+, CD10-, TdT-, and CD34-), and showing MLL rearrangement without MYC rearrangement at presentation. Both infants relapsed after months of morphologic and genetic remission. At relapse, the t(9;11) translocation was detected in both cases by spectral karyotyping. After the initial relapse, both cases followed a rapid and aggressive course. Literature search identified few similar cases, all expressed lambda surface immunoglobulin and showed MLL rearrangement (majority with the t(9;11) translocation). These cases show that B-ALL with MLL rearrangement, especially the t(9;11) translocation, can express a 'mature' B-cell phenotype and may represent a distinct subset. Identification of additional cases will further clarify the significance of MLL rearrangements in mature B-ALL.

The spectrum of acute lymphoblastic leukemia with mature B-cell phenotype

We showed heterogeneous disease spectrum among 15 acute lymphoblastic leukemia (ALL) cases with mature B-cell phenotype diagnosed over the past 7 years at our institution. Besides those with typical L3 morphology and 8q24 (c-myc) translocation (n=6), there were cases showing L1 or L2 morphology without 8q24 translocation (n=6), unusually large L3 blasts in hyperdiploid clone (n=2) and blastoid variant of mantle cell lymphoma (n=1). The expression of CD5 and cyclin D1 may need to be routinely determined on ALL cases with mature B-cell phenotype and non-L3 morphology to facilitate timely diagnosis of blastoid MCL and institution of suitable management.

Acute lymphoblastic leukaemia of the L3 subtype in adults in the Northern health region of England 1983-99

AIM

Acute lymphoblastic leukaemia (ALL) with an L3 morphological FAB type is regarded by some as being synonymous with B cell ALL or ALL with a Burkitt-type chromosomal translocation-t(8;14), t(2;8), t(8;22). This paper describes a series from a population based study of 24 patients with L3 ALL presenting over 17 years.

METHODS

Clinical data were collected prospectively from all adult patients presenting with acute leukaemia in the Northern region since 1982. Data from all patients diagnosed with FAB type L3 ALL were analysed.

RESULTS

Overall, L3 ALL accounts for 8.6% of all adult ALL and it is more common in the elderly than has hitherto been recognised. In addition to classic Burkitt-type translocations (11 of 24 cases), the t(14;18) translocation, which is characteristically found in lower grade lymphomas such as follicular lymphoma, is frequently present (five of 24 cases).

CONCLUSION

The presence of L3 ALL is often associated with non-Burkitt-type translocations and the presence of a t(14;18) translocation may indicate that in some cases a clinically non-apparent lymphoproliferative disorder, such as a low grade follicular lymphoma, has transformed to a more aggressive form and, thus, presents as a de novo acute leukaemia.