RESUMO
Recently, we and others described a new chromosomal rearrangement, that is, inv(7)(p15q34) and t(7;7)(p15;q34) involving the T-cell receptor beta (TCRbeta) (7q34) and the HOXA gene locus (7p15) in 5% of T-cell acute lymphoblastic leukemia (T-ALL) patients leading to transcriptional activation of especially HOXA10. To further address the clinical, immunophenotypical and molecular genetic findings of this chromosomal aberration, we studied 330 additional T-ALLs. This revealed TCRbeta-HOXA rearrangements in five additional patients, which brings the total to 14 cases in 424 patients (3.3%). Real-time quantitative PCR analysis for HOXA10 gene expression was performed in 170 T-ALL patients and detected HOXA10 overexpression in 25.2% of cases including all the cases with a TCRbeta-HOXA rearrangement (8.2%). In contrast, expression of the short HOXA10 transcript, HOXA10b, was almost exclusively found in the TCRbeta-HOXA rearranged cases, suggesting a specific role for the HOXA10b short transcript in TCRbeta-HOXA-mediated oncogenesis. Other molecular and/or cytogenetic aberrations frequently found in subtypes of T-ALL (SIL-TAL1, CALM-AF10, HOX11, HOX11L2) were not detected in the TCRbeta-HOXA rearranged cases except for deletion 9p21 and NOTCH1 activating mutations, which were present in 64 and 67%, respectively. In conclusion, this study defines TCRbeta-HOXA rearranged T-ALLs as a distinct cytogenetic subgroup by clinical, immunophenotypical and molecular genetic characteristics.
Assuntos
Proteínas de Homeodomínio/genética , Leucemia-Linfoma de Células T do Adulto/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Adolescente , Adulto , Criança , Deleção Cromossômica , Inversão Cromossômica , Feminino , Rearranjo Gênico do Linfócito T , Proteínas Homeobox A10 , Humanos , Imunofenotipagem , Leucemia-Linfoma de Células T do Adulto/patologia , Leucemia-Linfoma de Células T do Adulto/fisiopatologia , Masculino , Pessoa de Meia-Idade , Receptor Notch1/genética , Ativação Transcricional , Translocação GenéticaRESUMO
Blueberry Muffin baby is a rare neonatal skin disorder. Many causes are known, examples are congenital infections, hemolysis and tumors. We report on a newborn presenting with Blueberry Muffin syndrome and an adrenal mass which lead to the diagnosis of neuroblastoma. Actually, it corresponded to an acute monoblastic leukaemia with an adrenal localization and a cerebrospinal fluid involvement. Leukaemia should always be considered in such patients, even in the absence of blasts on white blood cells count and bone marrow examination, as in this patient. This observation was also unusual due to spontaneous remission. The patient is in complete remission at 1 year follow-up.
Assuntos
Leucemia Mieloide Aguda , Dermatopatias/congênito , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide Aguda/diagnóstico , Remissão Espontânea , Dermatopatias/diagnóstico , Fatores de TempoRESUMO
Pediatric acute myeloid leukemia (AML) is a rare disease whose prognosis is highly variable according to factors such as chromosomal abnormalities. Recurrent genomic rearrangements are detected in half of pediatric AML by karyotype. NUcleoPorin 98 (NUP98) gene is rearranged with 31 different fusion partner genes. These rearrangements are frequently undetected by conventional cytogenetics, as the NUP98 gene is located at the end of the chromosome 11 short arm (11p15). By screening a series of 574 pediatric AML, we detected a NUP98 rearrangement in 22 cases (3.8%), a frequency similar to CBFB-MYH11 fusion gene (4.0%). The most frequent NUP98 fusion gene partner is NSD1. These cases are homogeneous regarding their biological and clinical characteristics, and associated with bad prognosis only improved by bone marrow transplantation. We detailed the biological characteristics of these AML by exome sequencing which demonstrated few recurrent mutations (FLT3 ITD, WT1, CEBPA, NBPF14, BCR and ODF1). The analysis of the clonal structure in these cases suggests that the mutation order in the NUP98-rearranged pediatric AML begins with the NUP98 rearrangement leading to epigenetic dysregulations then followed by mutations of critical hematopoietic transcription factors and finally, activation of the FLT3 signaling pathway.
Assuntos
Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Translocação Genética , Alelos , Biomarcadores Tumorais , Proteínas Estimuladoras de Ligação a CCAAT/genética , Criança , Pré-Escolar , Epigênese Genética , Exoma , Feminino , Regulação Leucêmica da Expressão Gênica , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hibridização in Situ Fluorescente , Lactente , Recém-Nascido , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidade , Masculino , Mutação , Proteínas de Fusão Oncogênica/genética , Prognóstico , Transdução de Sinais , Proteínas WT1/genética , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
The first EORTC (European Organization of Research and Treatment of Cancer) acute myeloblastic leukemia (AML) pilot study (58872) was conducted between January 1988 and December 1991. Out of 108 patients, 78% achieved complete remission (CR), and event-free survival (EFS) and survival rates (s.e., %) at 7 years were 40 (5) and 51% (6%), respectively. It indicated that mitoxantrone could be substituted for conventional anthracyclines in the treatment of childhood AML without inducing cardiotoxicity. The aim of the next EORTC 58921 trial was to compare the efficacy and toxicity of idarubicin vs mitoxantrone in initial chemotherapy courses, further therapy consisting of allogeneic bone marrow transplantation (alloBMT) in patients with an HLA-compatible sibling donor or chemotherapy in patients without a donor. Out of 177 patients, recruited between October 1992 and December 2002, 81% reached CR. Overall 7-year EFS and survival rates were 49 (4) and 62% (4%), respectively. Out of 145 patients who received the first intensification, 39 had a sibling donor. In patients with or without a donor, the 7-year disease-free survival (DFS) rate was 63 (8) and 57% (5%) and the 7-year survival rate was 78 (7) and 65% (5%), respectively. Patients with favorable, intermediate and unfavorable cytogenetic features had a 5-year EFS rate of 57, 45 and 45% and a 5-year survival rate of 89, 67 and 53%, respectively.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos Antineoplásicos/normas , Transplante de Medula Óssea , Leucemia Mieloide Aguda/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Idarubicina/uso terapêutico , Lactente , Recém-Nascido , Leucemia Mieloide Aguda/mortalidade , Masculino , Mitoxantrona/uso terapêutico , Indução de Remissão , Taxa de Sobrevida , Transplante HomólogoRESUMO
Chromosomal abnormalities of erythroleukemia (EL) are often described as complex and unspecific. A retrospective study of 75 EL defined following the WHO classification was performed by the Groupe Francophone de Cytogénétique Hématologique (GFCH) in order to reexamine the cytogenetics of this infrequent leukemia subtype. Clonal chromosomal abnormalities were found in 57 patients (76%), distributed in 4 subgroups according to their ploidy status: pseudodiploid (16%), hypodiploid (47%), hyperdiploid (19%), and 18% mixed cases associating 2 different clones (hypodiploid+hyperdiploid) or (pseudodiploid+hyperdiploid). Complex rearrangements and hypodiploid chromosome number were widely dominant (50%). Partial or entire monosomies represented 56% of abnormalities. Chromosomes 5 and 7 were the most frequently involved (41 and 33 times, respectively), followed by chromosomes 8, 16, and 21 (19 times each). Unbalanced abnormalities were more frequent than balanced. All these kinds of abnormalities were observed in de novo as well as in secondary EL. Four out of 7 cases of "pure erythroid" leukemia were associated with a BCR-ABL fusion. Lastly, no chromosome abnormality specific to EL could be established. However, the large overlap of chromosomal abnormality patterns of EL (pure erythroid form excepted) and refractory anemia with excess of blasts in transformation (RAEB-t) favors the hypothesis of similarities between these 2 hematologic disorders.
Assuntos
Aberrações Cromossômicas , Leucemia Eritroblástica Aguda/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Cromossomos Humanos , Humanos , Pessoa de Meia-Idade , Ploidias , Estudos Retrospectivos , Análise de SobrevidaRESUMO
The present study describes a novel cell line, MIELIKI, established from bone marrow of a pediatric patient with B lineage acute lymphoblastic leukemia (ALL) at diagnosis. The MIELIKI cell line displays an early pre-B cell phenotype (CD10+, CD19+, CD20+, CD34-, Cmu-, sIg-) with rearrangements on both Ig heavy chain and k light chain alleles, and carries an unfrequent t(7;9) chromosomal translocation identical to the freshly isolated leukemic blasts. The proliferation of MIELIKI cells was abrogated by IL-4 and by IL-7, as measured by DNA replication and viable cell recovery. The effects of IL-4 and IL-7 were mediated, respectively, through the CDw124 and CDw127 IL-4 and IL-7 receptor components. Growth inhibition by IL-4 was not mediated by soluble factors released by MIELIKI cells in response to IL-4, suggesting the existence of an intrinsic negative signaling pathway. Finally, neither IL-4 nor IL-7 were found to induce maturation of MIELIKI into cells expressing cytoplasmic or surface membrane mu chain. The present cell line should constitute a useful model of t(7;9) early pre-B ALL and allow investigation of the relationship between IL-4 and IL-7 negative signaling in leukemic B cell ontogeny.
Assuntos
Cromossomos Humanos Par 7 , Cromossomos Humanos Par 9 , Interleucina-4/farmacologia , Interleucina-7/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Translocação Genética , Antígenos CD/metabolismo , Divisão Celular , Feminino , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Rearranjo Gênico de Cadeia Leve de Linfócito B , Humanos , Lactente , Cariotipagem , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Receptores de Interleucina/metabolismo , Receptores de Interleucina-4 , Receptores de Interleucina-7 , Transdução de Sinais , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologiaRESUMO
The present study describes the establishment of the cell line Pre-Alp from the bone marrow of a pediatric patient with a t(1;19) pre-B acute lymphoblastic leukemia (ALL) at diagnosis. Proliferation of leukemic blasts was found to be initially dependent on the presence of autologous stromal cells. However, after five weeks of culture, the stromal cells were no longer necessary and cells began to grow autonomously, with a doubling time of approximately 24 hours. The established Pre-Alp cell line displays a pre-B cell phenotype (CD19+, CD10+, CD34-, c mu+, s mu-), with immunoglobulin (Ig) light chain DNA in germline configuration, and carries a (1;19)(p23;q13.3) chromosomal translocation identical to the freshly-isolated leukemic blasts. A unique feature of this cell line is represented by its ability to respond to interleukin 7 (IL-7). Thus, IL-7 enhances 3H-thymidine uptake by Pre-Alp cells in a dose-dependent manner, under conditions of low cell density and serum concentration, and increases cell recovery. Finally, Pre-Alp cells were found to remain at a pre-B stage even upon addition of various cytokines, which failed to induce a transition to surface Ig+ cells. The presently described cell line should constitute a useful model of t(1;19) pre-B ALL and permit the study of IL-7 dependent signal transduction in human pre-B cells.
Assuntos
Linhagem Celular , Cromossomos Humanos Par 19 , Cromossomos Humanos Par 1 , Interleucina-7/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Translocação Genética , Sequência de Bases , Northern Blotting , Divisão Celular , Criança , Feminino , Humanos , Imunofenotipagem , Cariotipagem , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Células Tumorais CultivadasRESUMO
To accurately estimate the incidence of HOX11L2 expression, and determine the associated cytogenetic features, in T-cell acute lymphoblastic leukemia (T-ALL), the Groupe Français de Cytogénétique Hématologique (GFCH) carried out a retrospective study of both childhood and adult patients. In total, 364 patients were included (211 children =15 years and 153 adults), and 67 (18.5%) [47 children (22.4%) and 20 adults (13.1%)] were shown to either harbor the t(5;14)q35;q32) translocation or express the HOX11L2 gene or both. Most of the common hematological parameters did not show significant differences within positive and negative populations, whereas the incidence of CD1a+/CD10+ and cytoplasmic CD3+ patients was significantly higher in positive than in negative children. Out of the 63 positive patients investigated by conventional cytogenetics, 32 exhibited normal karyotype, whereas the others 31 showed clonal chromosome abnormalities, which did not include classical T-ALL specific translocations. Involvement of the RANBP17/HOX11L2 locus was ascertained by fluorescence in situ hybridization in six variant or alternative (three-way translocation or cytogenetic partner other than 14q32) translocations out of the 223 patients. Our results also show that HOX11L2 expression essentially occurs as a result of a 5q35 rearrangement, but is not associated with another identified T-ALL specific recurrent genetic abnormality, such as SIL-TAL fusion or HOX11 expression.
Assuntos
Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 5/genética , Proteínas de Homeodomínio/genética , Leucemia-Linfoma de Células T do Adulto/genética , Proteínas Oncogênicas/genética , Translocação Genética , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Células Clonais , Feminino , Humanos , Imunofenotipagem , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Ploidias , Proteínas Proto-Oncogênicas , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de SobrevidaRESUMO
Thrombocytosis is frequently observed in pediatric patients. Among them the secondary thrombocytosis are the most frequent and result from several causes. The rarely primary thrombocytosis can be either constitutive (and often familial) or acquired (essential thrombocythemia). The purpose of this article is to give diagnostic orientation and to suggest which biological tests should be performed.
Assuntos
Trombocitose/diagnóstico , Tempo de Sangramento , Criança , Diagnóstico Diferencial , Humanos , Contagem de Plaquetas , Testes de Função Plaquetária , Trombocitemia Essencial/diagnóstico , Trombocitose/sangue , Trombocitose/etiologiaRESUMO
Hemophagocytic syndromes are a heterogeneous group of diseases characterized by an excessive immune response, mediated by activated cytotoxic T cells and macrophages. Among hemophagocytic syndromes, genetic and secondary forms can be distinguished. We report on the case of a male newborn who presented with macrophage activation syndrome associated with lymphoproliferation with favorable outcome under prednisone and cyclosporin. Hemopathy, infection, or genetic lymphohistiocytosis were initially ruled out. Severe autoimmunity was suspected because of positive antinuclear antibodies and Farr test associated with anemia and a positive Coombs test as well as cytolytic hepatitis with anti-liver, kidney microsome (LKM) antibodies. Treatment was therefore intensified by adding mycophenolate mofetil. This led to an unexpected deterioration of general health and lab exam results with recurrence of fever and inflammation. The initial investigations were revisited and completed by a liver biopsy, which revealed the presence of numerous leishmania parasites at the amastigote stage, enabling the diagnosis of visceral leishmaniasis. The patient's condition dramatically improved under liposomal amphotericin B treatment. Our observation shows that visceral leishmaniasis can present as lupus-like syndrome with lymphoproliferation. Moreover, the lack of leishmania on marrow aspiration cannot rule out the diagnosis of visceral leishmaniasis. Detection of leishmania by serological or molecular tests is mandatory in case of hepatosplenomegaly with hemophagocytic syndrome together with autoantibodies, in order to avoid useless and life-threatening exposure to immunosuppressive treatments.
Assuntos
Autoimunidade , Leishmaniose Visceral/complicações , Síndrome de Ativação Macrofágica/parasitologia , Humanos , Lactente , MasculinoRESUMO
Between September 1986 and June 1997, 24 children with high-risk ALL in CR1 were allografted after TAM (fractionated TBI, high-dose Ara-C, and melphalan; n = 10) or BAM protocol (busulfan, high-dose Ara-C, and melphalan; n = 14). The EFS for transplants from sibling donors was 33% with TAM and 62% with BAM (P = 0.148). The probability of acute GvHD was 70% with TAM and 15% with BAM (P = 0.003). Four of 17 evaluable patients relapsed: one after TAM and three after BAM. In all, 46 other children transplanted in CR beyond CR1 were studied for sequelae. Long-term side effects were more frequent in TAM vs BAM. In children with ALL, busulfan may be a good alternative to TBI to improve the quality of life.
Assuntos
Transplante de Medula Óssea/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Condicionamento Pré-Transplante , Transplante Homólogo/métodos , Adolescente , Bussulfano/administração & dosagem , Criança , Pré-Escolar , Citarabina/administração & dosagem , Feminino , Doença Enxerto-Hospedeiro , Humanos , Imunofenotipagem , Cariotipagem , Masculino , Melfalan/administração & dosagem , Organofosfatos/administração & dosagem , Recidiva , Fatores de Tempo , Resultado do TratamentoRESUMO
miR-16, a miRNA involved in cell proliferation and apoptosis regulation, may interfere with either oncogenic or tumor-suppressor pathways and is implicated in leukemogenesis. We then explored its expression in 93 childhood acute lymphoblastic leukemia (ALL) cases. A high miR-16 expression was associated with hyperleukocytosis and poor cytogenetic groups. In the whole group and in B-cell ALLs, disease-free survival (DFS) was significantly shorter for miR-16 above quartile 75. In T-cell ALLs, for both DFS and overall survival, a significant trend was found with a survival shortening from the lowest to the highest miR-16 levels. miR-16 expression neither significantly correlated with normal and malignant lymphocyte proliferation nor varied according to lymphocyte differentiation. The prognostic value of miR-16 in childhood ALL highlighted the complexity of miR-16 functions.
Assuntos
Proliferação de Células , Linfócitos/citologia , MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Northern Blotting , Linhagem Celular Tumoral , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , PrognósticoRESUMO
BACKGROUND: Infections remain an important cause of morbidity and mortality in children with acute myeloid leukemia (AML), and particularly viridans group streptococci (VGS) sepsis. The present study, conducted between 1993 and 2003 in children with AML, sought to assess the frequency and characteristics of infectious complications (ICs), the incidence of VGS sepsis, the interest of preventive decontamination, and a possible cytarabine dose-effect on the occurrence of ICs. METHODS: Medical charts of 78 children treated according to the EORTC 58921 clinical trial were analyzed retrospectively. Patients were isolated in laminar air flow rooms, received non-absorbable gut decontamination, gum decontamination with vancomycin mouthwash, and trimethoprim-sulfamethoxasole. ICs were categorized as microbiologically documented infections (MDI), clinically documented infections (CDI), or fever of unknown origin (FUO). RESULTS: Overall, 268 ICs occurred: 57.5% FUO, 8.5% CDI, and 34% MDI. Bloodstream infections occurred in 58 febrile episodes: Gram-positive bacteria represented 83% of the pathogens including 66.1% Staphylococcus species and 8.5% Streptococcus species (6.8% VGS), Gram-negative bacteria represented 13.5% of the pathogens and yeasts 3.5%. Five patients died of infection (6.4%). None died from bacterial infection and no case of VGS sepsis required intensive care. Invasive fungal infection was proven in four patients. Number of ICs was significantly different according to gum and gut decontamination status, and according to the cytarabine dose during the first intensification. No resistant strains were detected in spite of the use of local antibiotics. CONCLUSION: The low rate of VGS and enterobacteriaceae sepsis was probably due to the effective decontamination. Our supportive care strategy could potentially help enhance overall survival in children with AML.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide/tratamento farmacológico , Sepse/complicações , Infecções Estreptocócicas/microbiologia , Estreptococos Viridans/efeitos dos fármacos , Doença Aguda , Adolescente , Criança , Pré-Escolar , Citarabina/farmacologia , Citarabina/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Controle de Infecções , Leucemia Mieloide/diagnóstico , Leucemia Mieloide/epidemiologia , Masculino , Estudos Retrospectivos , Sepse/tratamento farmacológico , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/prevenção & controle , Taxa de Sobrevida , Resultado do TratamentoRESUMO
In vitro cancer studies require models more appropriate than the standard monolayer cultures of tumoral cell lines. This report describes the production of an in vitro three-dimensional rebuilt tumor using a non-hodgkin malignant lymphoma. The model exploits the relationship between angiogenesis and cancer formation by employing both tumor cells and fusiform cells derived from an angioma. The significance of this model, which has also been used with malignant melanoma cells, is that the rebuilt tumor, when placed in culture, produces many tumorous nodules which are fixed to a sub-layer of fusiform cells and newly-secreted matrix. These are, in effect, in vitro metastases. The ultrastructural aspect of this neomatrix indicates its proteoglycan nature. The micro-environment formed by the vascular cells and matrix appears to be critical for the production of metastases.
Assuntos
Linfoma não Hodgkin/patologia , Linhagem Celular Transformada , Matriz Extracelular/ultraestrutura , Técnicas In Vitro , Linfoma não Hodgkin/ultraestrutura , Metástase Neoplásica/ultraestrutura , Células Tumorais Cultivadas/patologia , Células Tumorais Cultivadas/ultraestruturaRESUMO
One of the difficulties in characterization of the oncogenes involved in thyroid carcinogenesis is the production of cell lines. Arising from a poorly differentiated thyroid papillary carcinoma we have established a cell line synthesizing the thyroglobulin and human chorionic gonadotropin (alpha and beta subunits) (HCG) hormones. These cells will allow research of the oncogenes involved or potentially involved in thyroid papillary carcinomas and evaluation of the role of the autocrine secretion of HCG.
Assuntos
Carcinoma Papilar/patologia , Gonadotropina Coriônica/metabolismo , Neoplasias da Glândula Tireoide/patologia , Células Tumorais Cultivadas/metabolismo , Humanos , Tireoglobulina/metabolismo , Células Tumorais Cultivadas/patologiaRESUMO
We report four cases of a rare subtype of CD30-positive anaplastic large cell lymphoma (ALCL) with a predominant small cell component (small cell variant of ALCL) presenting with a leukaemic feature. Lymph node biopsy showed malignant cells of varying size with a predominant population of small to medium-sized malignant cells associated with large anaplastic cells strongly positive for CD30 and epithelial membrane antigen (EMA). Both large and small cells were reactive with antibody ALK1, which recognizes the chimaeric NPM-ALK protein associated with the t(2;5)(p23;q35). All patients presented with hyperleucocytosis with atypical small lymphocytes. Bone marrow involvement was detected on both aspirate and bone marrow trephine where scattered malignant cells were only demonstrated by immunostaining for CD30 and ALK protein. Atypical cells in peripheral blood, lymph node and skin biopsies showed a T or null cell phenotype. Cytogenetic analysis of blood, bone marrow and/or lymph node revealed the t(2:5)(p23;q35) characteristic of ALCL. The patients responded to chemotherapy but showed early relapse without abnormal cells in peripheral blood. This report shows that the small cell variant of ALCL may have a leukaemic presentation with peripheral blood involvement by atypical lymphocytes and provides evidence that, in the small cell variant of ALCL, the small cell component is a part of the malignant clone.