Contribution of immunophenotype to the investigation and differential diagnosis of Burkitt lymphoma, double-hit high-grade B-cell lymphoma, and single-hit MYC-rearranged diffuse large B-cell lymphoma.

BACKGROUND: There are no immunophenotypic guidelines for the investigation of MYC-rearranged lymphomas. We aimed to identify simple immunophenotypic features that would help to differentiate between MYC-rearranged lymphomas and guide cytogenetic analysis. METHODS: We reviewed diagnostic samples from patients diagnosed with Burkitt lymphoma (BL), double-hit lymphoma (DHL), MYC-rearranged diffuse large B-cell lymphoma (MYC-DLBCL), and standard (non-MYC-rearranged) DLBCL over the last decade in our Institution. Using flow cytometry (with antibodies CD20, CD10, CD38, bcl-2, Ki-67, FMC-7, CD43, CD27, CD79b, CD23, and CD22) we determined antigen% expression and median-fluorescence intensity ratios (MFIR). The forward scatter (FS) and side scatter (SS) characteristics of tumor B-cells were compared with normal T-cells (B/T ratios) for patients with MYC-rearranged lymphomas. RESULTS: We identified 51 patients of whom 14 had BL, 10 had DHL (6 MYC+/BCL2+; 4 MYC+/BCL6+), 8 MYC-DLBCL, and 19 standard DLBCL. The significant differences (p <.05) were: higher CD38% in BL than standard DLBCL; higher CD10% in BL and DHL versus MYC-DLBCL and standard DLBCL; higher CD10MFIR in BL than MYC-DLBCL and standard DLBCL; higher Ki-67% in BL than DHL and MYC-DLBCL; higher bcl-2% in DHL than BL; higher FMC-7% in BL than MYC-DLBCL and standard DLBCL; and lower SS (B/T) ratio in DHL than MYC-DLBCL. CONCLUSIONS: The combination of CD38% > 90, CD10% > 80, CD10MFIR > 10, bcl-2% < 30, and Ki-67% > 70 was characteristic of BL. "Deviation" from these cut-offs should raise suspicion for DHL and, therefore, BCL2 and/or BCL6 FISH is required. We also found that a diagnosis of DHL rather than of MYC-DLBCL was significantly associated with CD10% > 60, Ki-67% > 50, and SS (B/T) <1.5.

Evaluation of automated capillary complete blood counts for routine clinical decision making in a large cohort of hematological patients, using Mindray BC-3000 Plus Auto and Sysmex XE-5000 hematology analyzers.

INTRODUCTION: Venous blood (VB) sampling for complete blood count (CBC) via venipuncture is the basic method for the daily evaluation of hematological patients. However, several issues during this process, such as venipuncture difficulty and repetitive attempts, may cause pain, phlebitis, hematomas, inadequate sampling, and patient discomfort. Capillary blood (CB) sampling could be an alternative and less painful solution for the patient. The purpose of this study was the comparative evaluation of basic CBC parameters, as counted from venous and capillary blood samples. METHODS: During the period 06/2016-06/2019 in which the study was conducted, 1634 automated counts of VB or CB were performed, derived from 425 hematological hospitalized patients. Bland-Altman plots were performed to show the agreement of VB and CB counts of common hematological parameters (Hb, Hct, WBC, absolute neutrophil count-[ANC], RBC, Plt, MCV, MCH), using two different hematology analyzers (Mindray BC-3000 Plus Auto and Sysmex XE-5000). Clinical significance of CB sampling was assessed by applying specific clinically significant cutoffs for Hb, ANC, and Plt. RESULTS: All measured parameters revealed a significant correlation (r > .9) between CB and VB samples, irrelatively of the hematology analyzer used. CB measurements of Hb, ANC, and Plt, at different clinically important cutoff levels, showed excellent sensitivity (87%-100%), specificity (95%-100%), positive predictive value, and negative predictive value (87%-100% and 90%-100%, respectively). CONCLUSION: Capillary blood and VB counts in hematological patients were equivalent for most basic hematological parameters. Hb, ANC, and Plt CB counts revealed clinically significant performance, indicating that they can reliably substitute VB sampling in the day work.

Dendritic Cell Leukemia: a Review.

PURPOSE OF REVIEW: The purpose of this review was to summarize the clinical, diagnostic, and therapeutic features of blastic plasmacytoid dendritic cell neoplasm (BPDCN). RECENT FINDINGS: Several case reports and series revealed new clinical, molecular, diagnostic, and therapeutic aspects of the disease. The clinical presentation diversity has been confirmed, with frequent leukemic non-cutaneous or rare atypical manifestations. The clonal evolution in the development of BPDCN has not been sufficiently elucidated. Although certain immunophenotypic markers (CD4, TCL1, CD123, CD56, CD303) are indicative of BPDCN, the diagnosis remains in certain cases challenging. Adult (ALL)-type chemotherapy followed by hematopoietic stem cell transplantation (HSCT) is related to a favorable outcome, while chemotherapy alone seems enough in children. Future studies should continue to investigate whether CD123-directed therapies could be utilized. BPDCN is a rare aggressive malignancy that needs an aggressive induction therapy. Although a diagnostic consensus is still lacking, and large retrospective studies are also needed to obtain standardized treatment guidelines, the future perspectives are encouraging, because of novel therapeutic agents that are under investigation.

Causes of double-negative T-cell lymphocytosis in children and adults.

AIMS: The causes and diagnosis of 'double-negative' (CD3+CD4-CD8-) T-cell lymphocytosis are not well studied. We aimed to define the causes of double-negative T-cell lymphocytosis in children and adults, and to identify simple clinical and laboratory features that would help to differentiate between the underlying conditions. METHODS: We collected clinical and laboratory data on 10 children and 30 adults with significantly increased peripheral-blood double-negative T-cells (>10% of total lymphocytes). We identified conditions associated with double-negative T-lymphocytosis with flow cytometry, peripheral-blood morphology and T-cell receptor-gene rearrangement studies. Patients were assigned to diagnostic categories on the basis of these test results. RESULTS AND CONCLUSIONS: The causes of double-negative T-cell lymphocytosis in children were autoimmune lymphoproliferative syndrome (ALPS) and reactive γ/δ Τ-lymphocytosis. T-cell large granular lymphocyte (T-LGL) leukaemia, reactive γ/δ T-lymphocytosis and hepatosplenic T-cell lymphoma (HSTL) were the the most common disorders underlying double-negative T-cell lymphocytosis in adults. Less common causes included hypereosinophilic syndrome, peripheral T-cell lymphoma, ALPS and monoclonal, double-negative T-lymphocytosis of uncertain significance. CD5/CD7/Vδ2 expression and absolute double-negative lymphocyte count (<1.8×109/L) were useful discriminators for distinguishing patients with reactive γ/δ T-lymphocytosis from those with γ/δ lymphoproliferative disorders. Differentiating between γ/δ T-LGL and HSTL can be difficult. Expression of CD57 and cellular morphology (pale cytoplasm with distinct granules) would support a diagnosis of γ/δ T-LGL.

Interference of bone marrow CD56+ mesenchymal stromal cells in minimal residual disease investigation of neuroblastoma and other CD45- /CD56+ pediatric malignancies using flow cytometry.

BACKGROUND: Bone marrow (BM) samples obtained from minimal residual disease (MRD)-negative children with B-cell acute lymphoblastic leukemia (B-ALL) were used in our laboratory as negative biological controls for the development of a neuroblastoma (NBL) flow-cytometric (FC) protocol. The accidental, but systematic, identification of rare cell populations (RCP) mimicking NBL cells (CD45- /CD56+ ) in these samples indicated the need for their thorough immunophenotypic identification, in order to elucidate their possible interference in NBL-MRD assessment. PROCEDURE: RCP observed in BM samples from 14 children recovering from BM aplasia due to intensive chemotherapy for B-ALL were investigated with the following markers: CD81, CD200, CD24, GD2, CD73, CD13, CD90, CD146, CD9, CD117, CD10, CD99, and NG2. BM samples from six newly diagnosed patients with NBL and an NBL cell line were simultaneously investigated as positive controls. RESULTS: The frequency of RCP in B-ALL BM samples was < 1/1 × 104 cells (bulky lysis), and their immunophenotypic profile was indicative of CD56+ mesenchymal stromal cells (MSCs) (CD45- , CD90+ , CD146+ , CD73+ ). Also, RCP expressed CD81 and CD200, simulating NBL cells. The most useful discriminative markers for CD56+ MSCs were CD13 and CD73. An appropriate protocol consisting of two tubes with seven color combinations was further proposed: SYTO-16, GD2 (first tube) or CD73 (second tube)-PE, CD24-ECD, CD13-PC5.5, CD45-PC7, CD81-APC, and CD56-APC700. CONCLUSIONS: RCP that were immunophenotypically similar to NBL were identified as CD56+ MSCs. As these cells might pose an obstacle to accurate NBL disease assessment by FC, especially MRD, an enhanced NBL-FC protocol is proposed for prospective evaluation.

"Bone marrow aspirate automated counts on hematology analyzers: formulating a scoring system based on hematology parameters, to discriminate reactive versus myelodysplastic syndrome-related bone marrows".

INTRODUCTION: Diagnosis of myelodysplastic syndromes (MDS) is usually challenging. In this context, we have attempted to employ data derived from automated analysis of bone marrow (BM) samples as an ancillary tool for the discrimination between reactive marrow and MDS. METHODS: A total of 101 BM anticoagulated samples referred for flow cytometry (FCM) analysis on the clinical suspicion of MDS had been previously counted in a Mindray BC-6800 hematology analyzer (testing set). Among them, 22/101 randomly selected BM samples (comparison set) had been also simultaneously counted by an Advia 2120 and a CELL-DYN Sapphire hematology analyzer. Selected parameters obtained by Mindray BC-6800 were retrospectively evaluated with ROC and regression analysis in an attempt to formulate a discriminative scoring system (SS) for MDS. This system was further evaluated in the comparison set. RESULTS: The diagnosis of MDS was established in 37/101 patients assessed ("MDS" group). Three patients were diagnosed with myelodysplastic/myeloproliferative neoplasm (MDS/MPN), while 61 revealed a "reactive" bone marrow ("RBM" group). Statistical analysis revealed significant differences in Hb, RDW-CV%, NRBC%, and RET% values between the "MDS" and the "RBM" group. Specific cutoff values were then indicated and employed for the formulation of a SS of high sensitivity (86.84%) and specificity (86.89%). The encouraging performance characteristics of the proposed SS were also confirmed in the BM comparison set. CONCLUSION: Automated BM counts on hematology analyzers contributed to the formulation of a SS for the screening discrimination between reactive and MDS BM fluids, which seems to be applicable and informative, regardless of the analyzer used.

Flow cytometric predictive scoring systems for common fusions ETV6/RUNX1, BCR/ABL1, TCF3/PBX1 and rearrangements of the KMT2A gene, proposed for the initial cytogenetic approach in cases of B-acute lymphoblastic leukemia.

INTRODUCTION: In B-acute lymphoblastic leukemia (B-ALL), the identification of cytogenetic prognostic factors is important for stratifying patients into risk groups and tailoring treatment accordingly. The purpose of this study was to propose flow cytometric (FCM) scoring systems (SSs) for predicting t(12;21)(p13;q22), t(9;22)(q34;q11), t(11q23), and t(1;19)(q23;p13.3) translocations. METHODS: We analyzed retrospectively the FCM immunophenotype of 377 patients with B-ALL with regard to the major cytogenetic findings revealed by interphase fluorescence in situ hybridization (i-FISH). Comparing descriptive data on the expression of each antigen and performing receiver operating characteristic (ROC) analysis, we identified the most reliable predictive markers for each translocation and sought to establish a specific SS for each translocation, based on specific antibody panels. RESULTS: CD27, CD9, CD66c, CD10, CD25, and CD34 were employed for the prediction of t(12;21), CD25, CD38, CD34, and CD66c for t(9;22), NG2, CD10, CD15, CD34, and CD20 for t(11q23), and CD34, cµ, CD123, and CD66c for t(1;19). The sensitivity and specificity, respectively, of each predictive score were 89.29% and 96.15% for t(12;21), 75.00% and 88.19% for t(9;22), 84.21% and 99.04% for t(11q23), and 85.71% and 92.71% for t(1;19). CONCLUSION: Four highly specific and significantly sensitive FCM-obtained SSs are proposed for the prediction of the four major translocations observed in patients with B-ALL. Prospective evaluation of the proposed SSs could lead to a better targeted cytogenetic investigation and therefore to more cost-effective laboratory practice.

Age-related prevalence of common upper respiratory pathogens, based on the application of the FilmArray Respiratory panel in a tertiary hospital in Greece.

The FilmArray Respiratory Panel (FA-RP) is an FDA certified multiplex PCR that can detect 17 viruses and 3 bacteria responsible for upper respiratory tract infections, thus it is potentially useful to the assessment of the age-related prevalence of these pathogens.In this observational study, we retrospectively analyzed the results of all the respiratory samples, which had been processed during 1 year-period (November 2015 to November 2016) with the FA-RP, in the Central Laboratories of Hygeia & Mitera General Hospitals of Athens, Greece. In order to have an age-related distribution, the following age groups were implemented: (<2), (≥2, <5), (≥5, <10), (≥10, <18), (≥18, <45), (≥45, <65), and (≥65) years old.Among 656 respiratory samples tested, 362 (55%) were from male and 294 (45%) from female patients, while 356 (54.3%) were positive and 300 (45.7%) negative. In the first age-group (<2), 41/121 samples (33.9%) revealed human rhinovirus/enterovirus (HRV) and 16 (13.2%) adenovirus (Adv), followed by respiratory syncytial virus (RSV), coronavirus, human metapneumovirus (Hmpv), and parainfluenza viruses (PIV). In the age-group (≥2, <5), Adv predominated with 37/147 samples (25.2%), followed by HRV, RSV, coronavirus (all types), and influenza, Hmpv and PIV. In the age-group (≥5, <10), HRV was identified in 25/80 samples (31.3%), Adv in 18 (22.5%), influenza in 11 (13.8%), and Hmpv in 6 (7.5%). Influenza predominated in the age-group (≥10, <18), with 4/22 samples (18.2%), while in the remaining age-groups (≥18), HRV was the commonest isolated pathogen, 33/286 (11.5%), followed by influenza with 20 (7%) (influenza A H1-2009, 11/20).In our patient series, HRV seemed to prevail in most age-groups, followed by Adv, although Influenza was the second most frequent pathogen isolated in the age-groups (≥18). Moreover, increasing age corresponded to increasing possibility of having a negative sample, indicating that FilmArray may be more useful before adolescence.

Liver disease in adult transfusion-dependent beta-thalassaemic patients: investigating the role of iron overload and chronic HCV infection.

BACKGROUND: Iron overload and hepatitis-C virus (HCV) infection, have been implicated in the evolution of liver disease, in patients with transfusion-dependent beta-thalassaemia major (BTM). However, the impact of these factors in late stages of liver disease in adults with BTM, has not been extensively studied. AIMS: To investigate serum indices of iron overload, HCV infection and liver disease, in a cohort of 211 adult Greek patients with BTM, in relation with the findings from liver biopsies. METHODS: In this cross-sectional study, 211 patients with BTM were enrolled and studied, in relation with HCV infection, ferritin, transaminases, chelation treatment and antiviral treatment. Based on 109 patients biopsied, we correlated liver fibrosis, haemosiderosis and inflammation, with serum indices and HCV status RESULTS: Among all patients, 74.4% were anti-HCV positive (HCV+). Ferritin was positively correlated with transaminases and negatively correlated with age, while it was not significantly different among HCV+ and HCV- patients. Among the HCV+ patients, 55.4% reported antiviral treatment, while genotype 1 predominated. In a subfraction of 109 patients, in which liver biopsy was performed, 89% were HCV+ and 11% HCV-. Fibrosis was significantly correlated with age (P = 0.046), AST (P = 0.004), ALT (P = 0.044) and inflammation (P < 0.001). Advanced fibrosis was present with even minimal haemosiderosis, independently of ferritin values or HCV history. CONCLUSIONS: These data suggest that in the late stages of liver disease in BTM patients, iron overload may be the critical determinant, since fibrosis is related to the minimal haemosiderosis, independently of HCV history.

Beta-thalassemia major and female fertility: the role of iron and iron-induced oxidative stress.

Endocrine complications due to haemosiderosis are present in a significant number of patients with beta-thalassemia major (BTM) worldwide and often become barriers in their desire for parenthood. Thus, although spontaneous fertility can occur, the majority of females with BTM is infertile due to hypogonadotropic hypogonadism (HH) and need assisted reproductive techniques. Infertility in these women seems to be attributed to iron deposition and iron-induced oxidative stress (OS) in various endocrine organs, such as hypothalamus, pituitary, and female reproductive system, but also through the iron effect on other organs, such as liver and pancreas, contributing to the impaired metabolism of hormones and serum antioxidants. Nevertheless, the gonadal function of these patients is usually intact and fertility is usually retrievable. Meanwhile, a significant prooxidants/antioxidants imbalance with subsequent increased (OS) exists in patients with BTM, which is mainly caused by tissue injury due to overproduction of free radicals by secondary iron overload, but also due to alteration in serum trace elements and antioxidant enzymes. Not only using the appropriate antioxidants, essential trace elements, and minerals, but also regulating the advanced glycation end products, could probably reduce the extent of oxidative damage and related complications and retrieve BTM women's infertility.

A simple flow cytometric assay for routine paroxysmal nocturnal hemoglobinuria testing based on immature reticulocytes and granulocytes.

BACKGROUND: The aim of this study was to test an easy-to-perform flow cytometric (FCM) assay for the routine investigation for diagnosis of paroxysmal nocturnal hemoglobinuria (PNH), through the simultaneous detection of PNH clones on immature reticulocytes (i-RET) and granulocytes. METHODS: During the last 5 years, eight patients were diagnosed with PNH in our laboratory, among 90 patients prospectively studied for PNH. The determination of glycosylphosphatidylinositol (GPI) deficient cells on the erythroid lineage was made with a two-color FCM assay of CD71 and CD59, evaluating the PNH clone on i-RET. Three color combinations based on CD66b/CD16/CD45 and CD59/CD24/CD45 were used for the determination of GPI-deficient granulocytes. RESULTS: In all the patients with PNH, the PNH clones determined with CD71(+)CD59(-) red blood cells (RBC) were nearly identical to the respective clones determined with CD16(dim/-)/CD66b(-) and CD59(-)/CD24(-) granulocytes, in contrast to the clones determined with CD59-deficient erythrocytes only, which were significantly lower. CONCLUSIONS: Our results indicate that the simultaneous assessment of the PNH clone on CD71(+)/CD59(-)i-RET and CD16(dim/-)/CD66b(-) granulocytes, could offer a reliable method of two series PNH screening, at low cost and with ease of application.

High frequency of human leukocyte antigen class II DRB1*1602 haplotype in Greek patients with myelodysplastic syndrome and of DRB1*1501 in the low-risk subgroup.

Myelodysplastic syndromes (MDS) comprise a heterogenous group of clonal hematopoietic disorders in which the immune-mediated pathogenetic mechanisms are under investigation. Overrepresentation of human leukocyte antigen (HLA)-DR2 and its serologic split HLA-DR15 has been associated with low-risk MDS in certain ethnic groups and has been proposed as a predictive factor for a favorable response to immunomodulatory treatment. Because the HLA-DRB1*15 haplotype does not predominate in the Greek population, we investigated the frequency of HLA-DRB1 alleles among 114 patients of Greek origin suffering from various types of MDS: 36 refractory anemia (RA), 24 refractory anemia with ringed sideroblasts (RARS), 19 refractory anemia with excess of blasts (RAEB), 14 refractory anemia with excess of blasts in transformation (RAEB-t), 14 chronic myelomonocytic leukemia, and 7 hypoplastic MDS patients. HLA-DRB1 molecular typing was performed with polymerase chain reaction-sequence specific oligonucleotides and results were compared with that from a previously reported control Greek population. HLA-DRB1*1602 was the only allele that was significantly overrepresented in Greek MDS patients as a whole, whereas HLA-DRB1*1501 allele frequency was significantly higher in Greek patients with low-risk myelodysplasia. Our results suggest the possible value of HLA-DR15 and HLA-DR16 as determinants for immunomodulatory interventions, at least for Greek patients with low-risk MDS.

Flow cytometry as a diagnostic tool in the early diagnosis of aggressive lymphomas mimicking life-threatening infection.

Aggressive lymphomas can present with symptoms mimicking life-threatening infection. Flow cytometry (FC) is usually recommended for the classification and staging of lymphomas in patients with organomegaly and atypical cells in effusions and blood, after the exclusion of other possible diagnoses. FC may also have a place in the initial diagnostic investigation of aggressive lymphoma. Three cases are presented here of highly aggressive lymphomas in young adults, which presented with the clinical picture of fever of unknown origin (FUO) in patients severely ill. All followed a life-threatening clinical course, and two developed the hemophagocytic syndrome (HPS), but microbiological, immunological, and morphological evaluation and immunohistochemistry (IHC) failed to substantiate an early diagnosis. FC was the technique that provided conclusive diagnostic evidence of lymphoma, subsequently verified by IHC. Our experience with these three cases highlights the potential role of FC as an adjunct methodology in the initial assessment of possible highly aggressive lymphoma presenting with the signs and symptoms of life-threatening infection, although the definitive diagnosis should be established by biopsy. In such cases, FC can contribute to the diagnosis of lymphoma, independently of the presence of HPS.

An improved flow cytometric assay for detection and discrimination between malignant cells and atypical mesothelial cells, in serous cavity effusions.

BACKGROUND: The aim of this study was to evaluate a flow cytometric assay for the detection of malignant effusions. METHODS: During the last 4-year period, 125 effusions suspicious for malignancy were prospectively analyzed by flow cytometry and conventional cytology. A three-step flow cytometric assay was performed, beginning with an initial informative panel of two protocols, containing SYTO-16, 7-AAD, CD71-PE, CD45-ECD, and CD66abce-FITC, CD64-PE, CD45-ECD, CD16-PECy5, CD14-PECy7, respectively. This was followed by a basic immunophenotypic panel of seven three-color combinations, containing in the first position, EMA, Ber-EP4, CD66abce, CD56, and intracellular desmin-33, combined with CD71-PE and CD45-PeCy5 in each tube. Finally, a cytokeratin-FITC/propidium iodide DNA panel was conducted, for the detection of aneuploidy in cytokeratin positive cells. RESULTS: The sensitivity and specificity of flow cytometry were 85.1 and 97.8%, and of cytology 93.2 and 95.6%, respectively. A significant association was observed between the results of the two techniques (P < 0.001). Among eight atypical cases detected by cytology, five had been precisely characterized as malignant by flow cytometry. EMA and Ber-EP4 proved the most sensitive markers for malignancy diagnosis, while the detection of desmin-33 negative/cytokeratin positive cells had the simultaneous highest positive and negative predictive values. CD66abce was very specific, although nonsensitive, while DNA ploidy analysis was nonspecific, as hyperploidy was observed in reactive mesothelial cells. CONCLUSIONS: A flow cytometric assay of high sensitivity and specificity is proposed for the routine identification of carcinoma cells in effusions and their distinction from atypical mesothelial cells, as an ancillary to conventional cytology.

Acute lymphoplasmacytoid dendritic cell (DC2) leukemia: results from the Hellenic Dendritic Cell Leukemia Study Group.

We present a cohort of 22 patients with type 2 dendritic cell (DC2) acute leukemia (or blastic plasmacytoid dendritic cell neoplasm-BPDCN, as it has been recently named), diagnosed in Greece over the past 12-year period, according to the main clinical and immunophenotypic features of this entity. Four additional cases are discussed, classified as leukemia of ambiguous lineage (LAL), because of the simultaneous detection of a CD56 negative DC2 population and of a second myeloid precursor cell population. The morphological features and cytogenetic findings of the typical BPDCN cases were similar to those previously described. Acute lymphoblastic leukemia-type chemotherapeutic regimens were more efficient in controlling the disease. Immunophenotyping of typical BPDCN cases revealed CD4(+), CD56(+), HLA-DR(+) and CD123(bright) neoplastic cells, in the absence of major B-, T- and myeloid-associated markers, while the phenotype of the four cases characterized as LAL highlights the risk of misdiagnosis. Based on our experience, we propose a flow cytometric algorithmic approach for the distinction of typical BPDCN from certain types of acute myeloid leukemia, but also for the identification of acute myeloid leukemia, admixed with CD56 negative DC2 cells, which could be misdiagnosed as BPDCN.

Report of an HIV and HHV-8 negative case of primary effusion lymphoma with idiopathic T4 lymphocytopenia.

Although primary effusion lymphoma (PEL) is usually associated with human herpes virus-8/Kaposi sarcoma herpes virus (HHV-8/KSHV) and human immunodeficiency virus (HIV), there are several reports of HHV-8/KSHV and HIV negative cases, mainly in the setting of immunodeficiency. Here, we report the second case of PEL associated with idiopathic T4 lymphocytopenia (ICL), which was HHV-8/KSHV negative, HIV negative and Epstein-Barr virus positive, while no other causative agents for immunodeficiency were documented. Flow cytometry revealed a hyperdiploid and highly mitotic large B-cell population, CD30, EMA, CD66, CD38 and CD71 positive. The malignant lymphoma cells showed atypia with prominent nuclei and basophilic vacuolated cytoplasm, while cytogenetic analysis with fluorescent in situ hybridization showed trisomy 18. The patient was administered R-COP chemotherapy, but no remission was achieved, up to 3 months from diagnosis.