The role of auto-HSCT in extranodal natural killer/T cell lymphoma.

Objectives: Autologous hematopoietic stem cell transplantation (auto-HSCT) is considered optional consolidation therapy especially for relapsed/refractory extranodal NK/T-cell lymphoma (ENKL), but its applications to newly diagnosed advanced-stage ENKL is currently limited. Methods: We collected 51 cases of newly diagnosed advanced-stage ENKL patients, including 26 with auto-HSCT and 25 with chemotherapy rather than HSCT, from our hospital between 2014/01 and 2023/12. We summarized the patients' characteristics, conducted survival analysis of the 51 cases, and analyzed the potential benefits of auto-HSCT to ENKL patients. Results: It shows that after a median follow-up time of 39 months, the estimated 5-year overall survival (OS) of the 51 newly diagnosed advanced-stage ENKL patients is 73.4%, and their estimated 5-year progression-free survival (PFS) is 73.4%. For patients receiving auto-HSCT, the 5-year OS (91.7%) and PFS (91.0%) are significantly different from those of patients receiving chemotherapy without HSCT (OS 53.3%, PFS 54.5%) (p < 0.05). Univariate and multivariate analysis results suggest that only the l-asparaginase usage in chemotherapy showed significant impact on the OS, and none of concerned factors showed significant impact on the PFS. Conclusions: Auto-HSCT is indeed an option to newly diagnosed advanced-stage ENKL, but further studies are still required for more strict disease management.

Nasal Extranodal NK/T Cell Lymphoma with Orbital Involvement: A Rare Entity of Common Presentations.

Nasal Extranodal NK/T Cell Lymphoma is an aggressive tumour affecting the nasal and midline structures, causing surrounding tissue destruction as the result of its progression. The initial presentations are similar to symptoms of benign nasal polyps, such as nasal obstruction, hyposmia and nasal discharge. As the disease progresses, the involvement of the palate, paranasal sinuses, orbit and skin become alarming symptoms. We report a case of a young male with Nasal ENKTL who presented with symptoms similar to acute on chronic rhinosinusitis with orbital complications. The challenges of diagnosing and getting to the correct management pathway are discussed.

Comprehensive population pharmacokinetic modelling of sugemalimab, an anti-programmed death-ligand 1 (PD-L1) human monoclonal antibody, in patients with solid tumours or lymphomas across multiple Phase I-III studies.

AIMS: The aim of this study was to develop a population pharmacokinetics model for sugemalimab, a monoclonal antibody that targets programmed death-ligand 1 (PD-L1), using data from Phase I-III trials and to assess clinical factors affecting sugemalimab exposure. METHODS: A nonlinear mixed-effect modelling approach was employed to analyse pooled data from nine studies involving 1628 subjects to characterize the PopPK of sugemalimab. This investigation examined the influence of various covariates on sugemalimab pharmacokinetics (PK), encompassing demographics, baseline hepatic and renal function-related covariates, and others (including anti-drug antibody [ADA], combination treatment, Eastern Cooperative Oncology Group [ECOG] performance score, tumour burden and tumour type). Estimation accuracy and predictive ability of the final model were evaluated using various methods. The influence of covariates on sugemalimab exposure was assessed by simulation from the final model. RESULTS: A two-compartment model with first-order elimination and time-varying clearance effectively described the PK of sugemalimab. Covariate analyses revealed significant relationships between sugemalimab clearance and body weight, albumin, gender, ADA, tumour burden and tumour type. The statistically significant covariates on central volume were body weight, albumin, gender and tumour type. No significant relationships were found in the final model for age, race, alanine aminotransferase, aspartate aminotransferase, creatinine, total bilirubin, alkaline phosphatase, combination treatment, creatinine clearance, ECOG, renal function or hepatic function. All significant covariates demonstrated less than a 20% effect on sugemalimab exposure. CONCLUSIONS: The PopPK model adequately described the pharmacokinetic profile of sugemalimab with no clinically meaningful impact observed on its exposure across all covariates. Dose adjustment does not appear to be necessary.

Primary pulmonary extranodal NK/T-cell lymphoma diagnosed by thoracoscopic lung biopsy: A case report.

A 63-year-old Japanese female presented with fever. Computed tomography showed multiple nodules in both lungs. Corticosteroids and antibiotics were administered to treat suspected organizing and bacterial pneumonia, resulting in no improvement and respiratory failure worsened. Surgical lung biopsy revealed infiltration of CD3, CD56, Granzyme B, and EBV-encoded RNA-ISH-positive atypical lymphocytes. She was diagnosed with primary pulmonary extranodal NK/T-cell lymphoma (ENKL) and died two months after diagnosis with only a temporary effectiveness of chemotherapy. We should consider the possibility of ENKL and perform prompt and appropriate biopsy for early diagnosis in cases where empiric therapy is ineffective for suspected pneumonia.

Quality of life in disease-free survived patients with early-stage extranodal nasal-type NK/T-cell lymphoma after definitive intensity-modulated radiotherapy: a cross-sectional study of 310 cases.

PURPOSE: Radiotherapy is a critical treatment for early-stage extranodal nasal-type NK/T-cell lymphoma (ENKTL) and has yielded favorable survival outcomes. However, their postradiotherapy quality of life (QOL) has not been investigated. Here, we conducted a cross-sectional study to assess the QOL of ENKTL patients with disease-free survival after definitive radiotherapy and to identify factors associated with QOL and treatment optimization. METHODS: This cross-sectional study included 310 patients with stage I-II ENKTL of the upper aerodigestive tract (UADT) who had received simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) with a consistent design and achieved disease-free survival. The median postradiotherapy time was 47.2 months (range, 3.1-115.7). The EORTC QLQ-H&N35 questionnaire was used to assess symptom-related QOL, and nine additional items were added to incorporate nasal, optical, and aural-related symptoms. The scores indicate the severity of the symptoms. RESULTS: The most common postradiotherapy symptoms among patients with ENKTL were nose problems (49.7%), dry mouth (44.8%), tooth problems (41.3%), sensory problems (32.6%), and less sexuality (25.8%). Tooth problems had the highest average score of 18.6, which is still acceptable. The severity of these symptoms decreased over time and reached a plateau in the second year after radiotherapy. Multivariable regression analysis showed that whole-neck irradiation was an independent predictive factor for xerostomia (P = 0.013, OR = 1.114), while age > 60 years was a predictive factor for lower sexuality (P < 0.001, OR = 1.32). CONCLUSION: The QOL of patients with early-stage ENKTL after radiotherapy was favorable, and most symptoms improved over time. Radiotherapy was correlated with specific symptoms, which may suggest a direction for further improvement in SIB-IMRT.

Expression of CD6 in Aggressive NK/T-cell Neoplasms and Assessment as a Potential Therapeutic Target: A Bone Marrow Pathology Group Study.

BACKGROUND: Aggressive NK/T-Cell neoplasms are rare hematological malignancies characterized by the abnormal proliferation of NK or NK-like T (NK/T) cells. CD6 is a transmembrane signal transducing receptor involved in lymphocyte activation and differentiation. This study aimed to investigate the CD6 expression in these malignancies and explore the potential of targeting CD6 in these diseases. MATERIALS AND METHODS: We conducted a retrospective study with totally 41 cases to investigate the expression of CD6 by immunohistochemistry, including aggressive NK-cell leukemia/lymphoma (ANKLL: N = 10) and extranodal NK/T-cell lymphoma (ENKTL: N = 31). A novel ANKLL model was applied for proof-of-concept functional studies of a CD6 antibody-drug-conjugate (CD6-ADC) both in vitro and in animal trial. RESULTS: CD6 was expressed in 68.3% (28/41) of cases (70% (7/10) of ANKLL and 67.7% (21/31) of ENKTL). The median overall survival (OS) for ANKLL and ENTKL cases was 1 and 12 months, respectively, with no significant difference in OS based on CD6 expression (p > 0.05, Kaplan-Meier with log-rank test). In vitro exposure of the CCANKL cell line, derived from an ANKL patient, to an anti-CD6ADC resulted in dose dependent induction of apoptosis. Furthermore, CCANKL engraftment in NSG mice could be blocked by treatment with the anti-CD6 ADC. CONCLUSION: To date, this is the first report to explore the expression of CD6 in ANKLL and ENKTL and confirms its expression in the majority of cases. The in vitro and in vivo data support further investigation of CD6 as a potential therapeutic target in these aggressive NK/T-cell malignancies.

Challenges in overcoming advanced-stage or relapsed refractory extranodal NK/T-cell lymphoma: meta-analysis of individual patient data.

Introduction: Extranodal NK/T-cell lymphoma (ENKTCL), a non-Hodgkin lymphoma, is known for its destructive local impact on nasal structures and systemic induction of inflammatory cytokines. Concurrent treatment with radiation and nonanthracycline- based chemotherapy has improved survival rates in patients with localized disease stages. However, survival outcomes vary significantly in advanced-stage and relapsed or refractory (R/R) cases. Methods: Therefore, we conducted a meta-analysis using random effects models to assess prognostic factors in advanced or R/R ENKTCL, employing a digital extractor on Kaplan-Meier graphs owing to the scarcity of published prospective trials for these patients. Results: We observed that patients with advanced ENKTCL treated with Lasparaginase had a median progression-free survival (PFS) of 14.3 months and an overall survival (OS) of 19 months. In R/R ENKTCL, PFS and OS were 11.7 and 15.6 months, respectively. Additionally, OS outcomes in advanced-stage ENKTCL were better in the asparaginase group than that in the non-asparaginase group, with PEG-asparaginase showing superior results compared with that using Lasparaginase. Epstein-Barr Virus (EBV)-DNA positivity in the bloodstream prior to treatment was associated with poor outcomes in advanced-stage ENKTCL, and similar trends were observed in patients with R/R ENKTCL and post-treatment EBV viremia. Discussion: Collectively, these findings suggest that chemotherapy with Lasparaginase or PEG-asparaginase can enhance survival in advanced or R/R ENKTCL. However, future strategies must be developed to effectively suppress EBV viremia and achieve a deep response toward tumor eradication.

Clinical Impact of Microbiome Characteristics in Treatment-Naïve Extranodal NK/T-Cell Lymphoma Patients.

Purpose: Extranodal NK/T-cell lymphoma (ENKTL) predominantly manifests in East Asia and Latin America. Despite shared intrinsic factors, such as ethnic and genetic backgrounds, the progression of ENKTL can be influenced by extrinsic factors related to changing lifestyle patterns. Materials and Methods: This study collected stool samples from newly diagnosed (ND)-ENKTL patients (n=40) and conducted whole genome shotgun sequencing. Results: ND-ENKTL revealed reduced alpha diversity in ND-ENKTL compared to healthy controls (HCs) (p=0.008), with Enterobacteriaceae abundance significantly contributing to the beta diversity difference between ENKTL and HCs (p<0.001). Functional analysis indicated upregulated aerobic metabolism and degradation of aromatic compounds in ND-ENKTL. Enterobacteriaceae were associated not only with clinical data explaining disease status (serum CRP, stage, prognosis index of natural killer cell lymphoma (PINK), and PINK-E) but also with clinical outcomes (early relapse and short progression-free survival). The relative abundance of Enterobacteriaceae at the family level was similar between ENKTL and diffuse large B-cell lymphoma (DLBCL) (p=0.140). However, the ENKTL exhibited a higher abundance of Escherichia, in contrast to the prevalence of Enterobacter and Citrobacter in DLBCL. Linear regression analysis demonstrated a significant association between Escherichia abundance and PD-L1 levels in tissue samples (p=0.025), whereas no correlation with PD-L1 was observed for Enterobacteriaceae at the family level (p=0.571). Conclusion: ND-ENKTL exhibited an abundance of Enterobacteriaceae and a dominant presence of Escherichia. These microbial characteristics correlated with disease status, treatment outcomes, and PD-L1 expression, suggesting the potential of the ENKTL microbiome as a biomarker and cause of lymphomagenesis, which warrants further exploration.

Genomic analysis reveals molecular characterization of CD30+ and CD30- extranodal natural killer/T-cell lymphomas (ENKTLs).

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is prevalent in the Asian population; however, little is known about its molecular characteristics. In this study, we examined the CD30 expression in ENKTLs and then performed whole exome sequencing on ten CD30+ ENKTL and CD30- ENKTL paired samples. CD30 was positive in 55.74% of the ENKTLs. Single nucleotide and insertion/deletion polymorphism analyses revealed that 53.41% of the somatic mutations in CD30+ ENKTLs were shared with CD30- ENKTLs, including mutations in SERPINA9, MEGF6, MUC6, and KDM5A. Frequently mutated genes were primarily associated with cell proliferation and migration, the tumor microenvironment, energy and metabolism, epigenetic modulators, vascular remodeling, and neurological function. PI3K-AKT, cAMP, cGMP-PKG, and AMPK pathways were enriched in both CD30+ and CD30- ENKTLs. Copy number variation analysis identified a unique set of genes in CD30+ ENKTLs, including T-cell receptor genes (TRBV6-1 and TRBV8), cell cycle-related genes (MYC and CCND3), immune-related genes (GPS2, IFNA14, TTC38, and CTSV), and a large number of ubiquitination-related genes (USP32, TRIM23, TRIM2, DUSP7, and UBE2QL1). BCL10 mutation was identified in 6/10 CD30+ ENKTLs and 7/10 CD30- ENKTLs. Immunohistochemical analysis revealed that the expression pattern of BCL10 in normal lymphoid tissues was similar to that of BCL2; however, its expression in ENKTL cells was significantly higher (67.92% vs. 16.98%), implying the potential application of BCL10 inhibitors for treating ENKTLs. These results provide new insights into the genetic characteristics of CD30+ and CD30- ENKTLs, and could facilitate the clinical development of novel therapies for ENKTL.

Primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting.

Posttransplantation primary cutaneous T-cell lymphomas (PT-CTCL) are a rare complication of sustained immunosuppression in the posttransplant setting. When present, PT-CTCLs are typically EBV- and exhibit features of mycosis fungoides/Sézary syndrome or CD30+ lymphoproliferative disorders. We present a case of a 75-year-old individual who developed skin lesions 30 years after liver transplantation. Pathologic evaluation of the skin biopsy revealed involvement by a clonal, EBV+ T-cell population of gamma/delta lineage with no evidence of systemic disease. Comprehensive genomic profiling was performed, confirming focal one-copy loss of 6q23.3, altogether consistent with the extremely rare and unusual diagnosis of primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting.

TET2 regulates extranodal NK/T cell lymphoma progression through regulation of DNA methylation.

The biological role of Ten-11 translocation 2 (TET2) and the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in the development of extra-nodal natural killer/T-cell lymphoma (ENKTL) remains unclear. The level of 5mC and 5hmC was detected in 112 cases of ENKTL tissue specimens by immunohistochemical (IHC) staining. Subsequently, TET2 knockdown and the overexpression cell models were constructed in ENKTL cell lines. Biochemical analyses were used to assess proliferation, apoptosis, cell cycle and monoclonal formation in cells treated or untreated with L-Ascorbic acid sodium salt (LAASS). Dot-Blots were used to detect levels of genome 5mC and 5hmC. Additionally, the ILLUMINA 850k methylation chip was used to analyze the changes of TET2 regulatory genes. RNA-Seq was used to profile differentially expressed genes regulated by TET2. The global level of 5hmC was significantly decreased, while 5mC was highly expressed in ENKTL tissue. TET2 protein expression was negatively correlated with the ratio of 5mC/5hmC (p < 0.0001). The 5mC/5hmC status were related to the site of disease, clinical stage, PINK score and Ki-67 index, as well as the 5-year OS. TET2 knockdown prolonged the DNA synthesis period, increased the cloning ability of tumor cells, increased the level of 5mC and decreased the level of 5hmC in ENKTL cells. While overexpression of TET2 presented the opposite effect. Furthermore, treatment of ENKTL cells with LAASS significantly induced ENKTL cell apoptosis. These results suggest that TET2 plays an important role in ENKTL development via regulation of 5mC and 5hmC and may serve as a novel therapeutic target for ENKTL.

Optimization of immune checkpoint inhibitor treatment planning for relapsed or refractory extranodal NK/T cell lymphoma.

Pembrolizumab (anti-programmed cell death-ligand 1 inhibitor) is a promising salvage therapeutic option for relapsed/refractory extranodal NK/T-cell lymphoma (R/R ENKTL). However, the appropriate duration of pembrolizumab use in R/R ENKTL patients and the optimal timing for administering pembrolizumab remain undetermined. We collected and analyzed clinical information on R/R ENKTL 58 patients who received pembrolizumab to evaluate the optimal treatment durations and clinical information for considering treatment interruption. Treatment outcomes were assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and Epstein Barr virus DNA (EBV DNA) every 3 months. Nineteen (32.8%) patients had been treated with more than three chemotherapies before pembrolizumab administration. The best response rate towards the first try of pembrolizumab was 38.9% (31.5% complete response rate (CR), 7.4% partial response (PR)). During the 41.8-month median follow-up duration, the median progression-free survival (PFS) was 3.1 months, and the median overall survival (OS) was 7.1 months. The failure group, which was characterized by Deaville score (DS) 3-4 and circulating EBV detection, or DS 5 with/without EBV detection, had the worst PFS (p < 0.001) and OS (p < 0.001), followed by the high (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected) and low-risk groups (DS 1-2 and EBV not detected). Among the 21 patients who achieved the best response at the first pembolizumab try, the patients who received planned 24 cycles presented better PFS than those who received incomplete cycles (57.6 months vs 20.9 months, P-value = 0.012). Among 13 patients who received avelumab or pembrolizumab in advance, a few who responded to the second trial of pembrolizumab administration had over one year of chemotherapy vacation. Determining the discontinuation or continuation of pembrolizumab would be considered in selected cases assessed by PET-CT and EBV monitoring. Disruption of pembrolizumab treatment may be advisable for the low-risk group(DS 1-2 and EBV not detected), whereas continuation could be warranted for the high-risk group (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected). Moreover, it might be critical to maintain over 24 cycles to improve the survival outcome of R/R ENKTL.

Analysis of the treatment and prognosis of 266 cases of extranodal natural killer/T-cell lymphoma, nasal type in a single medical center.

Objective: To assess the impact of different treatment strategies and risk factors on the prognosis of patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL) in a single medical center. Methods and analysis: The clinical features of 266 patients with ENKTL were retrospectively analyzed, among whom those in stages I and II received sandwich therapy, while those in stages III and IV underwent chemotherapy plus autologous hematopoietic stem cell transplantation. The Kaplan-Meier curves, univariate and multivariate Cox regression analyses were employed for survival and prognosis analysis. Statistical significance was set at P<0.05. Results: Following treatment, the post-intervention outcomes demonstrated a complete remission (CR) rate of 71.05% and a partial remission (PR) rate of 3.76%. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 70.4% and 70.9%, respectively. In addition, the PFS for patients in stage I/II was 79.8%, with an OS of 81.1%, whereas for those in stage III/IV, the PFS was 41.7% and the OS was 40.9%. Notably, the achievement of CR immediately after treatment was an independent prognostic factor (P<0.001). Patients in stage I/II depicted a favorable 5-year OS rate, while those in stage III/IV manifested a less favorable prognosis. Conclusion: Stages of the disease and whether CR was achieved following treatment are important factors determining the survival and prognosis of patients with ENKTL. Further researches focusing on disease onset and mechanisms of drug resistance will contribute to better management of ENKTL.

An Unusual Presentation of Midline Lethal Granuloma.

Extranodal natural killer T-cell lymphoma, nasal type (ENKTCL), is a rare form of non-Hodgkin lymphoma that is strongly related to Epstein-Barr Virus (EBV) infection and commonly presents as "midline lethal granuloma." Herein, we report a middle-aged lady who presented with a two-week history of fever, sore throat and constitutional symptoms. Intraoral examination revealed a lacerated soft palate with an ulcerated uvula. A diagnosis of ENKTCL was confirmed through deep biopsies under general anaesthesia supplemented with a positive serum EBV genome. Unfortunately, she succumbed due to disease progression with left frontal brain metastasis with concurrent pulmonary tuberculosis before treatment was completed. The recommended treatment is multimodality with L-asparaginase-containing regimes chemotherapy in an advanced stage, relapsed, or refractory ENKTCL for better outcomes. The quantification of circulating plasma EBV deoxyribonucleic acid (DNA) is helpful as the baseline of tumour load and a biomarker for monitoring treatment response and prognostication. We advocate repeated and deeper core tissue biopsies.

Extranodal natural killer/T-cell lymphoma coexisting with peripheral T-cell lymphoma, not otherwise specified.

We report the case of a 52-year-old male who presented to our hospital with cervical lymphadenopathy. Lymph node biopsy revealed small atypical lymphoid cells positive for CD3 and CD5 and negative for CD56 and Epstein-Barr virus (EBV)-encoded small RNA (EBER) by in situ hybridization. CD4-positive cells and CD8-positive cells were mixed in almost equal numbers. He was diagnosed with peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). The patient received one cycle of chemotherapy, resulting in severe sepsis. While undergoing treatment in the intensive care unit with an antimicrobial agent and prednisone, ascitic fluid appeared. Abdominal aspiration revealed neutrophil-predominant ascites and microbiological studies revealed Candida albicans. However, ascites did not improve when treated with micafungin for Candida peritonitis. Abdominal aspiration was re-performed, and atypical lymphoid cells that were positive for CD3 and CD56 were detected. EBV-DNA levels in whole blood were significantly elevated. Atypical lymphoid cells were positive for EBER by in situ hybridization and Southern blot analysis showed EBV terminal repeat monoclonal patterns. Bone marrow examination revealed the same atypical lymphoid cells. Therefore, the patient was diagnosed with extranodal natural killer/T-cell lymphoma (ENKTL) with bone marrow involvement 3 months after the diagnosis of PTCL-NOS. Complications associated with PTCL-NOS and ENKTL are rare. PTCL-NOS, chemotherapy, sepsis, and prednisone might have led to immunodeficiency and reactivation of EBV, which might be one of the pathophysiologies for developing ENKTL. Our case indicates that measuring EBV-DNA in the blood is a simple and prompt examination to detect complications of EBV-associated lymphoma.

Extranodal natural killer/T cell lymphoma nasal type simulating osteoradionecrosis with metachronic B lymphoma in the pelvis: Case report.

Extranodal Natural Killer/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT) is a non-Hodgkin extranodal lymphoma of unfavorable prognosis due to its aggressive nature. This neoplasm mainly affects the paranasal sinuses, nasopharynx, oropharynx, oral cavity, palate, and rarely intestinal, gastric and skin regions. 50-year-old female with a history of lymphoma in nasal and pelvic region. At four years of tumors-free, has facial asymmetry, accompanied by sub-palpebral, nasal and lip edema. Intraoral examination revealed a large ulceration suggestive of osteoradionecrosis. Gum biopsy shows Extranodal NK/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT). In this case we highlight the characteristics of EN-NK/T-CL-NT with a presentation of osteoradionecrosis-like. Unfortunately, the nature of this tumor led to the patient's death. Clinical follow-up of patients with cancer is imperative to mend and/or decrease treatment complications, as well as to identify second primary tumors or the spread of the underlying disease.

Initial diagnosis of extranodal NK/T-cell lymphoma in pericardial fluid with concomitant hemophagocytic lymphohistiocytosis (HLH).

Extranasal natural killer/T-cell lymphoma arising in the heart is rare and typically presents with non-specific clinical symptoms, necessitating a biopsy for a definitive diagnosis. We report an unusual case of a 48-year-old male who initially presented with chest pain and shortness of breath. Subsequent diagnosis via pericardial fluid analysis, including flow cytometry and immunohistochemical stains, revealed extranasal NK/T-cell lymphoma without sinonasal involvement. The analysis identified neoplastic lymphoid cells expressing CD2, cytoplasmic CD3, Epstein-Barr virus, and CD56 and exhibiting increased Ki-67 staining. Additionally, the patient developed hemophagocytosis lymphocytosis secondary to NK/T cell lymphoma. Treatment included an interleukin-1 receptor antagonist (anakinra), dexamethasone, rituximab, and etoposide. Unfortunately, the patient's condition rapidly deteriorated, leading to multiorgan failure and eventual demise. Given the rarity of this lymphoma, early diagnosis based on a high suspicion level provides the best chance for improved overall survival.