Leukaemic stem cells have heterogenous differentiation potential. The immunophenotypes of blast cells are usually consistent throughout the disease course even at relapse. Rarely, blast cells may undergo a ‘lineage switch’ during the course of disease especially during relapse. We would like to highlight such a case in a 10- year old boy who presented with a two weeks history of lethargy, poor appetite, low grade fever, respiratory distress, cardiac failure, generalized oedema and hepatosplenomegaly. Full blood count showed a leucocyte count of 41.5x109/L and platelet count of 37x109/L. The peripheral blood film showed presence of numerous blast cells. Bone marrow aspiration revealed a hypercellular marrow, which consisted of mainly blast cells with high nuclear to cytoplasmic ratio and inconspicuous nucleoli. Immunophenotyping and cytochemistry results were consistent with the diagnosis of T- cell acute lymphoblastic leukaemia. The patient achieved remission after treatment with UK ALL 97 protocol, regime B chemotherapy. However, he relapsed seven months after the initial diagnosis with 26% blast cells in the bone marrow aspirate. The majority was L1 blast cells admixed with some L2 blast cells. Immunophenotyping was consistent with common precursor B acute lymphoblastic leukaemia. The treatment was changed to a more lineage specific chemotherapy. Nonetheless, the patient never achieved remission and was planned for palliative management. This case illustrated a unique and rare case of rapid lineage switch from T-cell acute lymphoblastic leukaemia to common precursor B-cell acute lymphoblastic leukaemia.
Early Lineage Switch from T-Acute Lymphoblastic Leukaemia to Common B-All
Abstrak
Sel-sel stem leukemia mempunyai pelbagai potensi diferensiasi. Imunofenotip sel leukemia biasanya konsisten sepanjang riwayat penyakit walaupun pada peristiwa kambuh. Jarang-jarang sekali, sel leukemia mungkin mengalami 'lineage switch' terutamanya pada saat kambuh. Kami ingin menyoroti kes tersebut pada seorang kanak-kanak lelaki berusia 10 tahun yang mengalami kelesuan, hilang selera makan, demam, gangguan pernafasan, kegagalan jantung, edema dan hepatosplenomegali selama dua minggu. Keputusan darah menunjukkan jumlah leukosit 41.5x109/l dan platelet 37x109/l. Filem darah periferi dan sampel aspirasi sumsum tulang menunjukkan kehadiran sel leukemia dalam kuantiti yang banyak. Sel-sel itu mempunyai nisbah nukleus kepada sitoplasma yang tinggi. Imunofenotip dan sitokemia menunjukkan keputusan yang konsisten dengan diagnosis T-sel leukemia limfoblastik akut. Pesakit mencapai remisi selepas dirawat dengan kemoterapi rejim B ‘UK ALL 97 protocol’. Namun, penyakitnya kambuh tujuh bulan selepas itu dengan kehadiran sel leukemia sebanyak 26% di dalam sampel aspirat sumsum tulang. Majoriti adalah sel leukemia jenis L1 bercampur dengan minoriti sel leukemia jenis L2. Imunofenotip konsisten dengan leukemia prekursor B limfoblastik akut. Rawatan ditukar kepada kemoterapi yang lebih khusus, namun, pesakit tidak mencapai remisi dan kemudiannya rawatannya ditukar kepada kemoterapi paliatif. Kes ini mengilustrasikan kes 'lineage switch' awal dari T-sel limfoblastik leukemia akut kepada leukemia prekursor B limfoblastik akut.
Abstract
|
|
|
Related Images
a.jpg "Figure 1: Peripheral blood film of the patient showed presence of numerous blast cells with high nuclear:cytoplasmic ratio and inconspicuous nucleoli (arrow). (Wright stain, x 200)")
b.jpg "Figure 2: Flow cytometric analysis of the bone marrow sample showed a single population of blast cells (red) expressing CD 3, CD 7, CD 4 and CD8 but negative for CD 34 and B-markers.")
