Translocation (14;18) in a patient with common acute lymphoblastic leukemia (FAB l2)

Translocation (14;18)(q32;q21) in acute lymphoblastic leukemia: a study of 12 cases and review of the literature

We present a series of 12 cases of de novo acute lymphoblastic leukemia (ALL) with translocation t(14;18)(q32;q21). The median age of patients at presentation was 65.5 years, and no patient presented with a past history or any clinical evidence of lymphoma. A Burkitt translocation was identified in 4 of the 12 cases by conventional cytogenetics but fluorescence in situ hybridization using a MYC probe identified a further three cases of MYC rearrangement: one with a cryptic t(8;14) involving the der(14)t(14;18), one showing MYC translocated onto a marker chromosome, and one associated with a t(8;9)(q24;p13) translocation. A review of the literature identified an extremely close association between the t(14;18) and the t(8;9), with the latter translocation found only in the presence of t(14;18). The present study confirms the previously reported dismal prognosis of t(14;18)-associated ALL.

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.

B-cell acute lymphoblastic leukemia with L1 morphology and coexistence of t(1;19) and t(14;18) chromosome translocations

We report a case of adult de novo acute lymphoblastic leukemia (ALL) with unique cytogenetic abnormalities and discrepant morphologic and immunologic features. Morphology was L1 by the French-American-British classification, but flow cytometry was consistent with a mature B-cell phenotype. Cytogenetic analysis showed numerous chromosome abnormalities nonspecific for lymphoid neoplasm except for t(1;19) and t(14;18). The former is characteristic of pre-B-ALL and the latter is characteristic of follicular lymphoma. This is the first report of these two translocations occurring concurrently in ALL.

Possibilities and limitations of cytochemical methods in diagnosis of acute leukemia

Accurate identification and classification of leukemic blast cells is a very important prerequisite of the precise diagnosis of acute leukemia and has a great impact on therapy and prognosis. The purpose of this review is to consider, in the broad sense of the word, the present possibilities and limitations of enzyme cytochemistry and to emphasize how cytochemistry may contribute, on integration with the other methods of study, to the final classification and differential diagnosis of acute leukemia, a highly variable hematological disorder. In this review, the role of conventional enzyme cytochemistry, either dominant or subsidiary, in the discrimination of acute leukemia subtypes is discussed. The survey confirms the absolute necessity of immunologic marker analysis in the accurate diagnosis of acute lymphoblastic leukemia, undifferentiated or minimally differentiated leukemia and mixed-lineage leukemia because in these cases, the cytochemical evaluation provides insufficiently relevant information regarding blast cell origin, specificity of leukemia subtypes and the discrete stages of leukemic cell maturation. On the other hand, cytochemical investigation is appreciated to be dominant over immunophenotyping in characterizing acute myeloid leukemia, because of the lack of specificity of the majority of immunological markers against myeloid antigens and, because of the availability of standardized and sufficiently specific cytochemical reactions. The cytogenetic, molecular biological and electron microscopic studies mentioned in this review supplement the important information for correct differential diagnosis of acute leukemia. The prognostic impact of enzyme cytochemistry in correlation to other methods is evaluated.