Case Of T-cell Prolymphocytic Leukemia Research Articles

Comprehensive Cytogenetic and Molecular Genetic Characterization of T-PLL Identifies for the First Time BCOR Mutations in a Lymphatic Disease.

Abstract 2539 Introduction:T-cell prolymphocytic leukemia (T-PLL) is a rare mature post-thymic T-cell neoplasm with aggressive clinical course and a median overall survival of less than one year. Due to the rareness of this disease (∼2% of cases of mature lymphocytic leukemias in adults) only few cases with cytogenetic and molecular genetic aberrations have been reported so far. However, almost 75% of T-PLL cases are reported to harbor chromosome 14 abnormalities involving the TCRA/D locus resulting in the aberrant activation of the proto-oncogenes TCL1A or MTCP1. Aim:Perform a comprehensive cytogenetic and molecular characterization of T-PLL. Patient and Methods:The cohort comprised 36 T-PLL cases diagnosed between 10/2005 and 07/2012 (23 male, 13 female patients). Median age was 71.0 yrs (range: 26.8–82.8 yrs). According to the WHO classification all T-PLL cases were characterized using immunophenotyping and cytomorphology. Patients were further investigated using chromosome banding analysis (CBA) (n=30), FISH for deletions of ATM (n=30), TP53 (n=29), and 13q (n=26), and CGH arrays (n=3, Human CGH 6×630K Whole-Genome Tiling Array, Roche NimbleGen, Madison, WI). Further, mutation analyses for BCOR and TP53 were performed using amplicon sequencing (Roche 454, Branford, CT). Results:Aberrant karyotypes were observed by CBA in 25/30 cases (83.3%). However, the 5 remaining cases with normal karyotype were due to insufficient proliferation of the T-PLL clone as gains, losses and rearrangements were detected in these 5 cases using FISH analyses. In more detail, combined CBA and FISH data revealed in 20/30 (66.7%) cases an inv(14)(q11q32)/t(14;14)(q11;q32)/TCRA/D-TCL1A (n=18) or t(X;14)(q27;q11)/TCRA/D-MTCP1 (n=2). Further, a gain of chromosome 8q and concomitant loss of 8p was observed in 13/30 (43.3%) cases. In addition, in 10/25 (40.0%) cases a 6q deletion and in 7/25 (28.0%) an 12p deletion were observed. Based on FISH data, deletions were detected of ATM in 19/30 (63.3%) cases, TP53 in 7/29 (24.1%), and 13q in 9/26 (34.6%) cases.In addition, 3 cases were studied using array CGH. Hereby, an intragenic deletion in the BCOR gene was observed in one patient. BCOR is a BCL6 corepressor and located on chromosome Xp11.4. BCOR mutations were recently described in cases with AML. BCOR mutation frequency was determined at 3.8% in AML with normal karyotype and mutations were associated with shorter overall and event-free survival. The deletion in BCOR identified in one of our cases and the TP53 deletions in 7 T-PLL cases prompted us to screen 35 cases for molecular mutations in these two genes. Overall, BCOR mutations were detected in 5/35 (14.3%) patients and TP53 mutations in 4/35 (11.4%) cases. In total, 7 missense, one frame-shift and one nonsense mutations were found. Median mutation load was 90.0% for BCOR (range: 38–100%) and 80.0% (59–87%) for TP53.Next, we performed correlation analyses between mutations in BCOR and TP53, rearrangements involving chromosome 14, deletions of ATM, TP53, 6q, 12p, and 13q and gain of 8q. Here, BCOR was not associated with any of these parameters. In contrast, TP53 mutations were accompanied in all 4 cases by TP53 deletions, while only 3/24 TP53 wild-type cases harbored a TP53 deletion (P=0.002). In addition, only one of 4 TP53 mutated cases harbored a chromosome 14 rearrangement while 18/25 (72%) TP53 wild-type cases did (P=0.105). In line with this result, TP53 deletions were also negatively associated with chromosome 14 rearrangements (2/7 vs 17/22, P=0.030). Further, all cases with a gain of 8q harbored a 14q rearrangement (13/13 vs 8/18 without gain of 8q, P=0.001). Conclusions:1. CBA, FISH and mutation analysis of TP53 and BCOR revealed genetic abnormalities in all 36 analyzed cases. 2. The most frequent abnormality involved the TCRA/D locus (14q11) (20/30; 66.7%) activating the proto-oncogenes TCL1A on chromosome 14q32 (90.0%) or MTCP1 on chromosome Xq28 (10.0%). 3. Deletions were detected for ATM (63.3%), TP53 (24.1%), 6q (40.0%), 13q (34.6%), 12p (28.0%), and a gain was detected for the long arm of chromosome 8 (43.3%). 3. In addition to the detection of TP53 mutations in 11.4%, BCOR mutations were observed for the first time in a lymphatic malignancy with a mutation frequency of 14.3%. 4. The prognostic relevance of such cytogenetic and molecular genetic aberrations has to be determined in T-PLL, given that in myeloid malignancies both BCOR and TP53 are associated with shorter OS. Disclosures:Grossmann:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership.

“T-cell prolymphocytic leukemia (T-PLL), a heterogeneous disease exemplified by two cases and the important role of cytogenetics: a multidisciplinary approach”

T-cell prolymphocytic leukemia (T-PLL) is a rare form of leukemia composed of mature T-cells that usually presents in older people with a median age of 65. Most cases of T-PLL will harbor chromosomal abnormalities involving 14q11.2 (TCR alpha/delta), 14q32 (TCL1) or Xq28 (MTCP-1), abnormalities of chromosome 8, 12p and deletions of the long arm of chromosomes 5, 6, 11 and 13. Cytogenetics, FISH, comparative genomic hybridization (CGH) , SNP arrays with high resolution analysis have provided more precisely frequent submicroscopic gene and genomic lesions as well as breakpoints involved in the pathogenesis of this disease. One of the cornerstones to diagnose T-PLL are cytogenetic analysis. Here we summarize the current cytogenetic findings and we also describe two distinct cases of T-PLL where cytogenetics, FISH , morphologic analysis and flow cytometry helped to diagnose them accurately.

T-cell prolymphocytic leukemia in Japan: is it a variant?

T-cell prolymphocytic leukemia (T-PLL) is characterized by a post-thymic immunophenotype, salient chromosome abnormalities, and an aggressive clinical course. However, cases in which these features are absent have been occasionally reported in Japan. Here, clinical and biological features of 13 T-PLL cases, diagnosed between 1992 and 2009 in the Tohoku region of Japan, were compared with three Western series. Median age was 64 (range 40-78) years old, and the male to female ratio (12:1) was higher than that of the Western series (P < 0.04). Presented manifestations were similar to those of Western cases, but central nervous system involvement, which is rare in Western cases, was observed in 3 of 13 cases (23 %) (P < 0.04). Immunophenotypic patterns were similar to those of Western cases, but HLA-DR was positive in 6 of 9 cases (67 %), which is distinct from Western cases (0-9 %) (P < 0.002). By chromosome analyses, 14q11 abnormality and trisomy 8q, which are common among Western cases (70-80 %), were not observed in any cases (P < 0.002). Morphologically, seven were classified as typical type, five as a small-cell variant, and one as a cerebriform variant. Seven cases experienced an aggressive course, whereas six experienced an indolent course over a median follow-up of 50 months. In contrast to Western cases, clinical courses were closely correlated with morphological types; 86 % of typical types were aggressive, whereas 83 % of small-cell types were indolent (P = 0.025). On the basis of these observations, together with previous Japanese cases in the literature, we propose that Japanese cases of T-PLL may constitute a variant.

T-Cell Prolymphocytic Leukemia Accompanied by Plural M-Proteins with Myelodysplastic Syndroxme in a Nonagenarian

T-cell Pro-Lymphocytic Leukemia (T-PLL) is a rare disease caused by malignancy of mature post-thymic T-cell. Myelodysplastic Syndrome (MDS) is caused by abnormal differentiation of myeloid lineage cells resulting in myeloid leukemia. Both of these hematological disorders are frequently diagnosed in elderly persons. Myeloid lineage is believed to be situated at the position far from lymphoid one as it is regarded on a tree diagram about the blood cell maturation. We reported herein a rare case of T-PLL accompanied by plural M-proteins with MDS a nonagenarian. The 96 years old patient was admitted to our hospital because of lymphocytosis and abnormal lymphocytes. From the bone marrow aspirate, biopsy and hematological findings, abnormalities were observed in cells of three different lineages, namely, (i) neutrophils with hypersegmented-nuclei (ii) erythroblasts with nuclear division, large platelets and megakaryoblastic cells, and (iii) reticulum cells with phagocytosed iron in their cytoplasm. Lymphocytes showed CD3 (+), CD4 (±), CD5 (+), CD8 (+), CD10 (+), CD56 (-) and CD57 (-). Mast cells and large lymphocytic cells with nuclear pockets were also seen. Anti-HTLV-1 antibody was negative. Soluble IL-2 receptor was significantly elevated to 7910 U/ml. Both IgGλ and IgGκM-protein were detected. No Bence-Jones protein was detected in the urine. Chromosomal abnormality of 45 (X, 0) or loss of Y chromosome was also demonstrated. Due to his high age, it was difficult to classify his condition according to the conventional classification. Thus, what we had experienced is truly a rare case that coincidentally showed T-PLL and MDS with plural M-proteins.

TCL1A gene involvement in T-cell prolymphocytic leukemia in Japanese patients

T-cell prolymphocytic leukemia (T-PLL) is a rare type of peripheral T-cell leukemia. In this study, we examined the clinical and biological characteristics of 11 Japanese patients with T-PLL. Median age was 74years, with male predominance. Median lymphocyte frequency was 85.3% in blood. Physical characteristics were splenomegaly (36.4%), tiny lymph adenopathy (63.6%), skin lesion (9.1%) and pleural effusion (27.3%). Median survival was 30.1months, despite treatment with various chemotherapeutic modalities. Although complex chromosomal abnormalities were observed in 5 of 11 cases (45.5%), typical 14q32 and Xq28 abnormalities were not detected. TCL1A mRNA expression was observed in 6 of 11 cases (54.5%) on real-time quantitative PCR. In 5 of these 6 cases, flow cytometric analysis and/or immunohistochemistry confirmed the expression of TCLA1 protein. Split signals for the TCL1 region on fluorescence in situ hybridization confirmed rearrangement in 3 out of 7 cases evaluated. These cases corresponded to cases that were positive for TCL1A expression, suggesting that rearrangement of the TCL1 region induced high expression of TCL1A gene. In summary, a substantial number of T-PLL cases in Japan had abnormal expression of TCL1A, probably due to rearrangement of TCL1 region. Expression and/or rearrangement of TCL1A may, therefore, be a useful marker for diagnosing T-PLL, regardless of chromosomal abnormalities.

A case of T cell prolymphocytic leukemia involving blast transformation

We report a case of T cell prolymphocytic leukemia (T-PLL) involving blast transformation. At the initial diagnosis, most peripheral blood cells demonstrated proliferation of indolent T cell small cell variants, i.e., small to medium prolymphocytes with inconspicuous nucleoli and a normal karyotype. These cells were positive for surface CD4, CD5, and CD7, and cytoplasmic CD3, but negative for surface CD3 and CD8 and cytoplasmic terminal deoxynucleotidyl transferase (TdT). The T cell receptor (TCR) Cβ1 gene was rearranged in the cells. Large prolymphocytes with prominent nucleoli, irregular nuclei, and cytoplasmic vacuoles that exhibited chromosome 8 trisomy were observed about 1.5 years later. The CD4+CD8- single positive effector memory T cells transformed into surface CD4+CD8+ double positive precursor T cells. The clonal TCR gene rearrangement patterns of these cells were identical throughout the clinical course, suggesting clonal blast transformation. The CD4+CD8+ cells demonstrated increased chromosome 8 trisomy combined with complex chromosome abnormalities with t(14;14)(q11.2;q32) containing a 14q32 chromosome after transformation. T cell leukemia 1a (TCL1a) (14q32.1) may be implicated in this case. The TCL1a oncoprotein is expressed in approximately 70% of T-PLL cases. The disease gradually developed resistance to chemotherapy, and the patient died of the disease. It is known that indolent T-PLL can become aggressive. Therefore, similar transformations may occur in other aggressive T-PLL cases, particularly those involving trisomy 8 and TCL1a.

T-cell prolymphocytic leukaemia: spontaneous immunophenotypical switch from CD4 to CD8 expression

Dear Editor, A 48-year-old man was incidentally found to have a lymphocytosis, with haemoglobin: 14.1 g/dL, white cell count: 16.6 × 109/L (77% abnormal lymphocytes), and platelet count: 160 × 109/L. The abnormal lymphocytes were small, with scanty basophilic cytoplasm showing frequent blebs (Fig. 1a). The nuclei contained condensed chromatin and inconspicuous nucleoli. They were predominantly positive for CD4 (Fig. 1b), and expressed CD2, CD5, CD7 and T cell receptor (TCR) αβ. Karyotyping showed inv(14)(q11q32) with multiple karyotypic aberrations (Fig. 1c). Serologic test for human T-lymphotropic virus 1 was negative. The diagnosis was consistent with T-prolymphocytic leukaemia (T-PLL) [1]. The patient elected not to receive treatment. Eight months afterwards, he presented with erythematous rashes, generalised lymphadenopathy and splenomegaly. A full blood count showed haemoglobin: 10.9 g/dL, white cell count: 132 × 109/L (95% abnormal lymphocytes), and platelet count: 139 × 109/L. Interestingly, the lymphocytes showed a diminution in CD4, but an increase in CD8 expression (CD4+CD8–:23.9%, CD4–CD8+: 65.5%, CD4+CD8+: 10.6%; Fig. 1d). Skin biopsy confirmed leukaemic infiltration. The patient was treated with alemtuzumab (30 mg/day thrice weekly) for 4 weeks without response. Two courses of fludarabine, mitoxantrone, dexamethasone [2] and resumption of alemtuzumab were ineffective. Immunophenotyping 11 months after diagnosis showed that the PLL cells were predominantly CD8 expressing (CD4–CD8+:73.5%, and CD4+CD8+:25.8%; Fig. 1e). Owing to the poor response to alemtuzumab, CD52 expression was investigated. The PLL cells had retained CD52 expression (Fig. 1f). To investigate if a new clone might have emerged, polymerase chain reaction for TCR gamma gene was performed. Identical peaks were demonstrated despite a change from CD4 to CD8 expression (Fig. 1g). Splenectomy was performed, followed by combination chemotherapy (dexamethasone, methotrexate, ifosphamide, etoposide, L-asparaginase). However, the patient died of sepsis 2 weeks afterwards. Fig. 1 Pathological features of a case of T-cell prolymphocytic leukemia (PLL). a Abnormal lymphoid cells at diagnosis, showing condensed nuclei with inconspicuous nucleoli, and scanty basophilic cytoplasm with frequent blebs (Wright–Giemsa stain, original ... This case showed a number of interesting features pertinent to the diagnosis of T-PLL. The usual morphological features of prolymphocytes, viz., small to medium cells with a single distinct nucleolus and abundant cytoplasm, were not observed. The neoplastic cells were instead mature looking. It has been proposed that a diagnosis of “mature T cell leukaemia, unclassified” might be offered to such cases [3]. However, had the case presented later when CD8 expression predominated, a diagnosis of T cell large granular lymphocyte leukaemia might have been entertained. These diagnostic difficulties were resolved with demonstration of inv(14), implying that this case should be classified as the small cell variant of T-PLL [1]. The immunophenotypical switch from CD4 to CD8 was also intriguing. Molecular analysis confirmed that the CD4 to CD8 switch occurred in the same clone, implying that the immunophenotypical switch was an intrinsic property of the T-PLL cells. This phenomenon appeared to be exceptionally rare; and to our knowledge, only one similar case had been reported, in which a change from CD4 to CD8 expression was associated with large cell transformation [4]. Interestingly, the CD8+ phenotype had also been reported to be associated with a poor response to conventional chemotherapy [5]. Such observations were recapitulated in our case, which showed a relentless deterioration with increasing CD8 expression.

Allogeneic Hematopoietic Cell Transplant for Prolymphocytic Leukemia

The poor prognosis of patients with prolymphocytic leukemia (PLL) has led some clinicians to recommend allogeneic hematopoietic cell transplant (HCT). However, the data to support this approach is limited to case-reports and small case series. We reviewed the database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to determine outcomes after allotransplant for patients with PLL. We identified 47 patients with a median age of 54 years (range: 30-75 years). With a median follow-up of 13 months, progression-free survival (PFS) was 33% (95% confidence interval [CI] 20%-47%) at 1 year. The most common cause of death was relapse or progression in 49%. The cumulative incidence of treatment-related mortality (TRM) at 1-year posttransplant was 28%. The small patient population prohibited prognostic factor analysis, but these data support consideration of allotransplant for PLL. Further study of a larger population of patients is needed to determine which patients are more likely to benefit.

Translocations t(X;14)(q28;q11) and t(Y;14)(q12;q11) in T‐cell prolymphocytic leukemia

We report a case of T-cell prolymphocytic leukemia (T-PLL) in a 41-year-old male. Classical cytogenetic, spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) studies of a blood sample obtained at diagnosis revealed the co-existence of t(X;14)(q28;q11), t(Y;14)(q12;q11) and a ring chromosome derived from i(8)(q10). Immunophenotypic studies revealed involvement of T-cell lineage, with proliferation of CD4(-) CD8+. The co-existence of two translocations involving both sex chromosomes in a case of T-PLL is rare. Chromosomal instability associated with the disease progression may have allowed the emergence of cell clones with translocations involving the sex chromosomes and the ring chromosome observed.

T-cell prolymphocytic leukemia: a report of two cases with review of literature

T-cell Prolymphocytic Leukemia (T-PLL) is a mature post-thymic T-cell malignancy with aggressive clinical course. The principal disease characteristics are organomegaly, skin lesions and raised lymphocyte counts. We report two cases of T-PLL. T-PLL is a rare T-cell malignancy with characteristic clinical and laboratory features and a poor prognosis. It needs to be differentiated from B-Cell prolymphocytic leukemia (B-PLL) and other mature T-cell lymphoproliferative disorders with predominant leukemic pattern. Differentiation can be made by a comprehensive approach taking into account the clinical features, the cell morphology and the immunophenotype of leukemic cells.

High TCL1 expression and intact T-cell receptor signaling define a hyperproliferative subset of T-cell prolymphocytic leukemia

The T-cell leukemia 1 (TCL1) oncoprotein is overexpressed by chromosomal rearrangement in the majority of cases of T-cell prolymphocytic leukemia (T-PLL). In vitro, TCL1 can modulate the activity of the serine-threonine kinase AKT, a downstream effector of T-cell receptor (TCR) signaling. In a series of 86 T-PLL tumors, we show that expression of TCR, and levels of TCL1 and activated AKT are adverse prognostic markers. High-level TCL1 in TCR-expressing T-PLL is associated with higher presenting white blood cell counts, faster tumor cell doubling, and enhanced in vitro growth response to TCR engagement. In primary tumors and TCL1-transfected T-cell lines, TCR engagement leads to rapid recruitment of TCL1 and AKT to transient membrane activation complexes that include TCR-associated tyrosine kinases, including LCK. Pharmacologic inhibition of AKT activation alters the localization, stability, and levels of these transient TCL1-AKT complexes and reduces tumor cell growth. Experimental introduction and knockdown of TCL1 influence the kinetics and strength of TCR-mediated AKT activation. We propose that in T-PLL, TCL1 represents a highly regulated, targetable modulator of TCR-mediated AKT growth signaling.

Powerful strategy for polymerase chain reaction-based clonality assessment in T-cell malignancies Report of the BIOMED-2 Concerted Action BHM4 CT98-3936

Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies. To obtain reference values for Ig/TCR rearrangement patterns, 19 European laboratories investigated 188 T-cell malignancies belonging to five World Health Organization-defined entities. The TCR/Ig spectrum of each sample was analyzed in duplicate in two different laboratories using the standardized BIOMED-2 PCR multiplex tubes accompanied by international pathology panel review. TCR clonality was detected in 99% (143/145) of all definite cases of T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, peripheral T-cell lymphoma (unspecified) and angioimmunoblastic T-cell lymphoma (AILT), whereas nine of 43 anaplastic large cell lymphomas did not show clonal TCR rearrangements. Combined use of TCRB and TCRG genes revealed two or more clonal signals in 95% of all TCR clonal cases. Ig clonality was mostly restricted to AILT. Our study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T-cell malignancies assisting the firm diagnosis of T-cell neoplasms. The detected TCR gene rearrangements can also be used as PCR targets for monitoring of minimal residual disease.

T-cell prolymphocytic leukemia: An aggressive T cell malignancy with frequent cutaneous tropism

T-cell prolymphocytic leukemia (T-PLL), formerly categorized as T-cell chronic lymphocytic leukemia, is a rare and aggressive hematologic malignancy. Although the skin is characteristically involved, it is not a well-recognized entity in the dermatologic literature. Six cases of cutaneous T-PLL are presented from a clinical, light microscopic, and phenotypic perspective. The patient population comprised 2 women and 4 men, with a mean age of 69.8 years. The disease was associated in all with skin involvement with facial preference; edema, purpura, and lesional symmetry were characteristic. The skin biopsies demonstrated a largely non-epidermotropic angiocentric lymphocytic infiltrate with accompanying hemorrhage. The cells showed irregular- to reniform-shaped nuclei with small nucleoli and eosinophilic rims of cytoplasm. Phenotypic studies revealed three prevailing profiles: CD4 dominant in 4, CD8 dominant in one, and co-expression of CD4 and CD8 in one. CD3 loss was seen in one case. All expressed T-cell leukemia 1 (TCL-1) and CD7; cutaneous lymphocyte antigen expression was discernible in a dot-like perinuclear array. All cases tested excluding one expressed TCL-1 and CD52. In two cases tested, T-cell receptor beta rearrangements were observed. Cytogenetic studies demonstrated a paracentromeric chromosome 14 inversion. Polysomy 8 and MYC amplification was seen in one case, manifesting an aggressive clinical course. Four patients died from their disease within 18 months of diagnosis. Cytogenetic MYC amplification, FISH, and TCR beta studies were conducted on each of 2 cases, respectively, due to limitations of tissue block samples and/or peripheral blood. cMYC translocation studies were conducted on 3 of the 6 cases, again due to limitations imposed by the tissue samples on the cases. The last case was recently diagnosed and, therefore, long-term follow-up is not possible. T-PLL is a distinctive post-thymic T-cell malignancy with frequent cutaneous tropism. A diagnosis is possible in almost all cases based on characteristic clinical, light microscopic, phenotypic, and cytogenetic features. While a chromosome 14 inversion is highly characteristic, additional inherent cytogenetic differences, such as trisomy 8 with CMYC over-amplification, may account for some case to case variation in clinical course.

Translocation t(Y;14)(q12;q11): A New Abnormality Associated with r[i(8)(q10)] in T-Prolymphocytic Leukemia Studied by Classic Cytogenetics and Spectral Karyotype.

T-cell prolymphocytic leukemia (T-PLL) is a malignant proliferation of lymphoid cells with a mature postthymic phenotype. The disease is characterized by lymphadenopathy, splenomegaly, skin lesions, and elevated white blood cell count, and it is often resistant to conventional therapy. Classic cytogenetic studies have revealed the presence of complex karyotypes and some recurrent chromosomal abnormalities, of which the most frequent are t(14;14)(q11;q32), inv(14)(q11q32), t(X;14)(q28;q11), i(8)(q10), and t(8;8)(p12;q11). Conventional cytogenetic techniques are insufficient to fully characterize chromosomal abnormalities, especially complex and cryptic aberrations. In this report, we describe a case of T-PLL with t(Y;14)(q12;q11) and a ring chromosome r[i(8)(q10)] studied by classic cytogenetics and spectral karyotyping (SKY). These abnormalities have not been previously described in T-PLL. A 41-year-old man was admitted with night sweats, weight loss, lymphadenopathy and hepatosplenomegaly without skin rash. Peripheral blood counts were: platelets 128 x 109/L and leukocytes 93.6 x 109/L. Hemoglobin levels were 12.5 g/dL. Immunophenotypic studies showed the following results: CD2+, CD3+, CD5+, CD7+, CD4−, CD8+, T-cell receptor (TCR) a/b+, CD1-, and terminal deoxynucleotidyl transferase-negative (TdT-). The patient was treated with fludarabine and CHOP therapy, neither of which resulted in a response. The patient was then treated with alemtuzumab (Campath®) and complete resolution of lymphadenopathy and normalization of blood counts was achieved. Classic cytogenetic and SKY analyses were performed on a 3-day phytohemagglutinin-stimulated culture of peripheral blood lymphocytes. The observed karyotype was abnormal in 18 of the metaphases analyzed: 46, t(X;14)(q28;q11), t(Y;14)(q12;q11), r[i(8)(q10)]. The co-existence of 2 translocations involving both sex chromosomes in P-TLL is a rare occurrence; however, abnormalities involving band Xq28 (the site for the MCTP-1B1 gene which has homology to TCL-1 on 14q32.1) are common in T-PLL. In addition, translocations involving the 14q11-q13 region (TCRa and TCRd) result in juxtaposition of enhancer elements responsible for the expression of TCR genes next to different oncogene loci. This leads to disruption of transcriptional pathways involved in normal T cell development, and ultimately, leukemic transformation. The fibroblast growth factor receptor-1 (FGFR-1) gene, in 8p11, has been implicated in a recurrent breakpoint in a myeloproliferative syndrome associated with T-cell lymphoma and the monocytic leukemia zinc finger (MOZ) gene in acute myelogenous leukemia. The amplification of the q arm of chromosome 8 accompanied by deletion of 8p sequences distal to the breakpoints could mean that two events act synergistically to contribute to the malignant phenotype in T-PLL. It is possible to suggest that the loss of a tumor suppressor gene or activation of an oncogene on 8p cooperates with amplification of the q arm and/or the expression of TCL-1/MTCP-1B1 in T-PLL. Secondary abnormalities of chromosome 8 may play an important role in the development of T-PLL. In this case of T-PLL with rare cytogenetic abnormalities, treatment with alemtuzumab resulted in a clinical response.

Mycosis Fungoides, Sezary Syndrome or T-Cell Prolymphocytic Leukemia?.

Sézary syndrome (SS) is a cutaneous T cell lymphoma in which the demonstration of a T-cell clone in the skin and in the peripheral blood (PB) together with cytomorpho-immunophenotypical criteria are needed for a correct diagnosis besides the typical erytrhoderma and lymphadenopathies. In March 2004 a 63-year-old white man developed a rapidly growing and slightly itching squamous macular eruption on the interscapular region: skin biopsy revealed superficial dermal band-like infiltrates, consisting of small CD3+ CD4+ CD8- lymphocytes with epidermotropism and a few Pautrier's microabscesses, suggesting a diagnosis of mycosis fungoides (MF). A simultaneous blood involvement was detected with lymphocytosis (14000/μl), increased CD4, CD3, CD2, CD5, CD7 positive T cells and T cell receptor (TCR) Vβ5.1 chain monoclonality. As for initial staging, bone marrow (BM) trephine biopsy demonstrated an interstitial infiltrate of small CD3+ and CD5+ lymphocytes and CT scan did not show any visceral involvement or lymphoadenopathies. TCRγ and TCRδ gene rearrangement patterns in PB and BM analyzed by PCR showed, respectively, a monoclonal Jpγ and a oligoclonal Vδ3Jδ1 rearrangement. Circulating Lutzner cells were seen by electronic microscopy. Cytogenetic analysis in PB using fluorescence in situ hybridization (FISH) techniques revealed multiple abnormalities (add7q, i8q, 10p+, 12p-). In September 2004 the patient started chemotherapy with fludarabine 25 mg/m2 (days 1 to 5 every 4 weeks) for 5 courses. In April 2005 he was still in good condition, not showing skin lesions; CT scan was negative, but lymphocytosis had increased (45000/μl). A BM trephine biopsy and the cytogenetic analysis of PB confirmed the above mentioned alterations. Cytofluorimetric analysis of the CD4+ CD5+ CD7+ population showed two different pattern as regarding CD3 positivity; half of the T cells was expressing CD3 antigens on the membrane surface, the other half in the citosol; however both isoforms of the molecule expressed the same Vβ5.1 chain; another cytofluorimetric characteristic was the strong expression of CD5 and CD7 in terms of elevated fluorescence intensity, a characteristic feature of T-cell prolymphocytic leukemia (T-PLL). The study of TCRγ and TCRδ gene rearrangement in PB showed, respectively, a monoclonal Jpγ and a monoclonal Vδ3Jδ1 rearrangement. In May 2005 the patient started a second line therapy with 30 mg alemtuzumab administered subcutaneously 3 times a week. At the end of the 5th week a complete haematological, immunophenotypical and cytogenetic response was obtained, even if the molecular analysis showed a persistent clonal expansion of T cells. This case demonstrates that the currently proposed haematological, flowcytometric and molecular criteria for SS are not forceful enough to differentiate between SS, MF with blood involvement and some T-PLL cases. A more detailed characterization of Sezary cells is therefore needed. Some investigators suggest that a loss of T-cell lineage markers together with the amount of CD4+ CD26- cells in PB in an appropriate clinical and histological contest, could be a more sensitive criterion of SS.

Subset of T-Cell Prolymphocytic Leukemia Expresses CD117. Potential Target for Therapy.

IntroductionExcluding non-hematopoietic lesions, CD117 (c-kit) is expressed by erythroid, megakaryocytic and myeloid precursors, mature mast cells, subset of plasma cell neoplasm and occasional precursor lymphoblastic tumors. C-kit plays important role in T-cell development around birth, but the expression of CD117 in mature T-cell lymphoproliferations is rare. We present flow cytometry phenotypic data of 28 cases of T-cell prolymphocytic leukemia (T-PLL).Material and methodsMultiparameter 4-color FC analysis was performed on peripheral blood and/or bone marrow aspirate samples using the following antibodies: CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD13, CD14, CD16, CD19, CD20, CD25, CD33, CD34, CD38, CD45, CD56, CD64, CD79a, CD117, TCRab/γδ, TdT, and HLA-DR. Fresh bone marrow aspirates and/or peripheral blood films and cytospin preparations from FC samples were stained with Wright-Giemsa.ResultsT-PLL was diagnosed 28 cases. The ages ranged from 43 to 92 years. Normal expression of pan-T cell antigens (CD2, CD3, CD5, CD7) was present in 57%. Abnormal expression of one, two and three antigens was noted in 21%, 11% and 11%, respectively. 4 cases showed aberrant expression of CD117. Those cases were always CD8-positive (50% of T-PLL were CD4+). There were no pan-myeloid (CD13, CD33) and blastic (TdT, CD34) markers present. Molecular studies confirmed clonal rearrangement of TCR.DiscussionT-PLL is rare mature T-cell neoplasm characterized by marked lymphocytosis of small to medium-sized cells with conspicuous nucleoli. The response to conventional chemotherapy in T-PLL, similarly to other mature T-cell lymphoproliferations (except ALK+ anaplastic large cell lymphoma) generally is poor. While the use of alemtuzumab (Campath-1H) has improved remissions, the disease remains incurable. Novel treatment approaches, tailored to individual patients, and based on pathologic, phenotypic and molecular features will be crucial to improve survival for the patients with this disease.Based on the flow cytometry analysis of 28 cases of T-PLL we identified 4 cases with co-expression of CD117 (14%). When present, it is restricted to CD8+ tumors. We speculate that the expression of CD117 (c-kit) in these patients apart from its diagnostic utility, may serve as a criterion for a combination therapy with Campath-1H and imatinib mesylate.

T-cell prolymphocytic leukemia with der(11)t(1;11)(q21;q23) and ATM deficiency

T-cell prolymphocytic leukemia (T-PLL) is a rare mature T-cell malignancy and is similar to a mature T-cell leukemia seen in some patients with ataxia telangiectasia, which is a recessive hereditary chromosomal instability syndrome caused by mutations of the ataxia telangiectasia mutated ( ATM) gene located on 11q23. Intriguingly, recent studies have strongly implicated ATM in the pathogenesis of T-PLL as a tumor suppressor gene, because biallelic inactivation of ATM is frequently observed in this disease; however, translocations involving 11q23 have rarely been reported in T-PLL. We report here a case of T-PLL with der(11)t(1;11)(q21;q23). Southern blot analysis did not reveal any abnormality of ATM, nor of MLL, which is also located on 11q23 and is involved in t(1;11)(q21;q23) in acute myelomonocytic leukemia. Northern blot analysis further showed that the ATM transcript of normal size is expressed in the leukemic cells at a level higher than that in normal peripheral blood lymphocytes. Western blot analysis, however, revealed that expression of ATM in the leukemic cells is much lower than that in normal lymphocytes. These results imply that translation of the ATM transcript is impaired or that the ATM protein is highly unstable in the leukemic cells, thus suggesting the presence of nucleotide changes in both alleles.

Unusually indolent T‐cell prolymphocytic leukemia associated with a complex karyotype: Is this T‐cell chronic lymphocytic leukemia?

T-cell prolymphocytic leukemia (T-PLL) is typically associated with an aggressive clinical course, with a median survival of less than 1 year. We report a case of T-PLL that displays multiple cytogenetic abnormalities, with the most complex subclone having the following karyotype: 47, Y, -X, +8, inv (10) (p12q26), del (11) (p13p15) +marker. However, despite this genetic complexity, the leukemia has behaved in a remarkably indolent manner, with the patient remaining asymptomatic, without therapeutic intervention, for more than 7 years. The unusually benign behavior of this disease calls into question the validity of grouping such cases under the umbrella of T-PLL and warrants a reconsideration of T-cell chronic lymphocytic leukemia (no longer recognized as a distinct disease) as a bona fide diagnostic entity.

Are Activation Markers (CD25, CD38 and CD103) Predictive of Sensitivity to Purine Analogues in Patients with T-cell Prolymphocytic Leukemia and other Lymphoproliferative Disorders?

T-cell prolymphocytic leukemia (T-PLL) is a rare lymphoproliferative disorder with distinctive clinical and laboratory features. It is often resistant to conventional chemotherapy, but complete or partial responses have been documented with the use of purine analogues. We report on two cases of T-PLL with a slightly different immunophenotype but a remarkably different response to pentostatin. We discuss the possible therapeutic implications of this finding and establish a comparison between immunophenotype and sensitivity to purine analogues in patients with T-PLL and other chronic lymphoproliferative disorders.

Masquerade syndrome: T-cell prolymphocytic leukemia presenting as panuveitis

PURPOSE: To report a case of T-cell prolymphocytic leukemia with panuveitis as the primary presenting feature. METHODS: Case report. RESULTS: A 46-year-old woman presented with pain and blurred vision in the right eye. She was found to have signs of panuveitis with a central exudative retinal detachment. Further investigations revealed that she was suffering from the rare T-cell prolymphocytic leukemia. Both systemic and ocular manifestations of the disease resolved after chemotherapy with Campath-IH antigen and as she went into complete remission. The exudative detachment settled, and visual acuity recovered to 20/20. CONCLUSION: This case illustrates that leukemias can present with primarily ocular findings, and the sudden appearance of a serous retinal detachment with inflammatory signs in an otherwise healthy person warrants a thorough systemic screening for an underlying malignancy.