Primary plasma cell leukemia mimicking an adult T-cell leukemia-lymphoma: a case report.

BACKGROUND: Malignant plasma cells ofmultiple myeloma (MM), or plasma cell leukemia (PCL), may present highly variable morphologic aspects. Adult T-cell leukemia-lymphoma (ATLL) is a peripheral T-cell neoplasm composed of highly pleomorphic lymphoid cells. We report an unusual case ofprimary PCL with misleading cellular morphology and some clinical and biologic similarities simulating ATLL. CASE: A 40-year-old Caribbean man presented with asthenia, epistaxis and diffuse bone pain. Blood cell count showed anemia and thrombocytopenia and a hyperleukocytosis composed of deeply basophilic cells with a polylobulated nucleus resembling flower cells. An ATLL diagnosis was given at first, without ruling out the possibility of a PCL diagnosis. Hypercalcemia and lytic bone lesions were compatible with both diagnoses. Immunophenotyping was key to the diagnosis of primary PCL. CONCLUSION: Some clinical and biological overlap may exist between PCL and ATLL, leading to a false diagnosis or delaying a correct one. An accurate cytologic analysis leading to a rapid detection of plasma cell markers is essential for an early diagnosis.

Mechanisms of genesis of variant translocation in chronic myeloid leukemia are not correlated with ABL1 or BCR deletion status or response to imatinib therapy.

Many published studies have indicated that various mechanisms could be involved in the genesis of variant chronic myelogeneous leukemia (CML) translocations. These are mainly one-step or two-step mechanisms, associated or not with deletions adjacent to the translocation junction on der(9) or der(22) chromosomes (or both). Based on the mechanism of genesis, it has been suggested that the complexity may affect the occurrence of ABL1 and BCR deletions (either or both), or may be associated with the CML disease course, and thus could determine the response to imatinib therapy. Through a retrospective molecular cytogenetic study of 41 CML patients with variant Philadelphia chromosome (Ph), we explored the genesis of these variant rearrangements and analyzed the correlation with deletion status and imatinib efficiency. Our results confirmed that the one-step mechanism is the most frequent, evidenced in 30 of 41 patients (73%); 3 patients demonstrated other more complex multistep events and 8 patients (19.5%) harbored ABL1 or BCR deletions that are not significantly associated with the complexity of translocation genesis. We also found no association between one-step, two-step, or multistep mechanisms and the response to imatinib therapy.

Two successful pregnancies in a chronic myeloid leukemia patient treated with imatinib.

The number of CML patients in child-bearing age and treated with imatinib is increasing. These women may want to be pregnant or are actually pregnant while on imatinib. Physicians do not know when to stop the treatment and what the risks are for the foetus and the mother. We report a case of a CML patient treated with imatinib who has two children, now 3 years and 10 months of age, in good health. The mother was in complete molecular remission, relapsed during pregnancy and reverted to remission in both cases after delivery.

Abnormalities of the long arm of chromosome 21 in 107 patients with hematopoietic disorders: a collaborative retrospective study of the Groupe Français de Cytogénétique Hématologique.

Chromosome 21 is frequently rearranged in hematopoietic malignancies. In order to detect new chromosomal aberrations, the Groupe Français de Cytogénétique Hématologique collected a series of 107 patients with various hematologic disorders and acquired structural abnormalities of the long arm of chromosome 21. The abnormalities were subclassified into 10 groups, according to the location of the 21q breakpoint and the type of abnormality. Band 21q22 was implicated in 72 patients (excluding duplications, triplications, and amplifications). The involvement of the RUNX1 gene was confirmed in 10 novel translocations, but the gene partners were not identified. Eleven novel translocations rearranging band 21q22 with bands 1q25, 2p21, 2q37, 3p21, 3p23, 4q31, 6p24 approximately p25, 6p12, 7p15, 16p11, and 18q21 were detected. Rearrangements of band 21q11 and 21q21 were detected in six novel translocations with 5p15, 6p21, 15q21, 16p13, and 20q11 and with 1p33, 3q27, 5p14, 11q11, and 14q11, respectively. Duplications, triplications, amplifications, and isodicentric chromosomes were detected in eight, three, eight, and three patients, respectively. The present study shows both the wide distribution of the breakpoints on the long arm of chromosome 21 in hematopoietic malignancy and the diversity of the chromosomal rearrangements and the hematologic disorders involved. The findings invite further investigation of the 21q abnormalities to detect their associated molecular rearrangements.

Prognosis of inv(16)/t(16;16) acute myeloid leukemia (AML): a survey of 110 cases from the French AML Intergroup.

Acute myeloid leukemias (AMLs) carrying inv(16)/t(16;16) chromosomal abnormalities are associated with a good prognosis. However, studies of this AML subtype have been hampered by the few number of patients reported, frequently collectively considered with those with AML carrying the t(8;21) translocation. We performed a retrospective study in 110 patients with inv(16)/t(16;16) AML (median age, 34 years) prospectively enrolled in 6 trials conducted in France between 1987 and 1998, with the aim to investigate prognostic factors for complete remission (CR) achievement and outcome of CR patients in this AML subtype. CR rate was 93%. Bad-prognosis factors for CR achievement were higher white blood cell count (WBC) and lower platelet count (optimal cutpoints at 120 and 30 x 109/L, respectively). At 3 years, estimated overall survival, disease-free survival (DFS), and cumulative incidence of relapse were 58%, 48%, and 42%, respectively. In multivariate analysis, (1) advanced age (optimal cutpoint, 35 years) was the only factor for shorter DFS and (2) advanced age and low platelet count were the 2 factors for shorter survival of CR patients. Outcome of CR patients (1) was not influenced by WBC and cytogenetic findings and (2) was similar among patients allocated to receive allogeneic transplantation, high-dose, or intermediate-dose cytarabine. Interestingly, advanced age was associated with a trend for more frequent additional chromosome abnormalities and predictive of higher cumulative incidence of relapse rather than death in first CR. These results markedly contrast with those reported in patients with t(8;21) AML in whom WBC, and not age, was the main high-risk factor for relapse, DFS, and survival.

HOX11L2 expression defines a clinical subtype of pediatric T-ALL associated with poor prognosis.

The most frequent oncogenic activation events characterized in childhood T acute lymphoblastic leukemia (T-ALL) result in the transcriptional activation of genes coding for transcription factors. The main genes are TAL1/SCL, a member of the basic region helix-loop-helix gene family, and HOX11L2, a member of the homeobox-containing protein family. To gain insight into the pathogenesis of this type of hematologic malignancy, we analyzed 28 T-ALL samples. SIL-TAL1/SCL fusion was detected in 6 patients; expression of HOX11L2 was observed in 6 patients and of HOX11 in 3 patients. With one exception, these activations did not occur simultaneously in the same patients, and they allowed the subclassification of 50% of the patients. SIL-TAL1 fusion was detected in association with HOX11 expression in one patient and with a t(8;14) (q24;q11) in another. High expression of LYL1, LMO2, or TAL1 was observed mainly in samples negative for HOX11L2 expression. HOX11L1 and HOX11 expression were observed in one instance each, in the absence of detectable chromosomal abnormality of their respective loci, on chromosomes 2 and 10, respectively. HOX11L2 expression was associated with a chromosome 5q abnormality, the location of the HOX11L2 locus in each case tested. Finally, our data show that HOX11L2 expression was a suitable marker for minimal residual disease follow-up and was significantly associated with relapse (P =.02).