Questionnaire for diagnosing asthma-COPD overlap in COPD: Development of ACO screening questionnaire (ACO-Q).

BACKGROUND: The considerable prevalence and worse outcomes of asthma-COPD overlap (ACO) in COPD have been reported, and optimal introduction of ICS is essential for ACO. However, diagnostic criteria for ACO consist of multiple laboratory tests, which is challenging during this COVID-19 era. The purpose of this study was to create a simple questionnaire to diagnose ACO in patients with COPD. METHODS: Among 100 COPD patients, 53 were diagnosed with ACO based on the Japanese Respiratory Society Guidelines for ACO. Firstly, 10 candidate questionnaire items were generated and further selected by a logistic regression model. An integer-based scoring system was generated based on the scaled estimates of items. RESULTS: Five items, namely a history of asthma, wheezing, dyspnea at rest, nocturnal awakening, and weather- or season-dependent symptoms, contributed significantly to the diagnosis of ACO in COPD. History of asthma was related to FeNO >35 ppb. Two points were assigned to history of asthma and 1 point to other items in the ACO screening questionnaire (ACO-Q), and the area under the receiver operating characteristic curve was 0.883 (95% CI: 0.806-0.933). The best cutoff point was 1 point, and the positive predictive value was 100% at a cutoff of 3 points or higher. The result was reproducible in the validation cohort of 53 patients with COPD. CONCLUSIONS: A simple questionnaire, ACO-Q, was developed. Patients with scores ≥3 could be reasonably recommended to be treated as ACO, and additional laboratory testing would be recommended for patients with 1 and 2 points.

[THE OVERLAPPING ELIGIBILITY FOR BIOLOGICS IN PATIENTS WITH SEVERE ASTHMA AND PHENOTYPES].

BACKGROUND: Biologics are an important treatment option for patients with severe asthma. Four biologics are available in Japan, and an overlapping eligibility has been observed. The eligibility and availability of drugs depend on the local regulations of different countries. However, there is no precise information about the eligibility for biologics, including dupilumab, in Japan. The aim of the study was to investigate the overlapping eligibility and to analyze the phenotypes of patients with multiple eligibility. METHODS: In this observational study, a retrospective chart review of patients was performed. The eligibility criteria for omalizumab were IgE 30-1500IU/mL and positive IgE for perennial aeroallergen. The eligibility criteria for IL-5-targeted biologics (mepolizumab and benralizumab) were eosinophil counts (Eos) > 150µL, while those for dupilumab were Eos > 150µL or fraction of exhaled nitric oxide (FeNO) > 150ppb or IgE > 167IU/mL. Severe asthma was defined by the severity criteria under treatment based on Japanese guidelines for adult asthma. RESULTS: One hundred patients with severe asthma were identified. The eligibility for omalizumab, IL-5-targeted therapies, and dupilumab was 43%, 69%, and 82%, respectively. Thirty percent of the patients were eligible for all the four biologics and showed the lowest FEV1, frequent exacerbation history, and the highest levels of Eos, FeNO, and serum periostin. Only 11% of the patients were not indicated for any biologics. CONCLUSION: A considerable portion of patients was eligible for all the biologics. Asthma control was poor, and type 2 inflammation was prominent in such patients.

IL-9 Blockade Suppresses Silica-induced Lung Inflammation and Fibrosis in Mice.

Recapitulative animal models of idiopathic pulmonary fibrosis (IPF) and related diseases are lacking, which inhibits our ability to fully clarify the pathogenesis of these diseases. Although lung fibrosis in mouse models is often induced by bleomycin, silica-induced lung fibrosis is more sustainable and more progressive. Therefore, in this study, we sought to elucidate the mediator(s) responsible for the pathogenesis of lung fibrosis, through the use of a mouse model of silica-induced lung fibrosis. With a single nasal administration of 16 mg of silica, lung inflammation (assessed by elevated cellular components in the BAL fluids [BALFs]) and lung fibrosis (assessed by lung histology and lung hydroxyproline levels) were induced and sustained for as long as 24 weeks. Of the mediators measured in the BALFs, IL-9 was characteristically elevated gradually, and peaked at 24 weeks after silica administration. Treatment of silica-challenged mice with anti-IL-9-neutralizing antibody inhibited lung fibrosis, as assessed by lung hydroxyproline level, and suppressed the levels of major mediators, including IL-1ß, IL-6, IL-12, CCL2, CXCL1, and TNF-α in BALFs. Moreover, human lung specimens from patients with IPF have shown high expression of IL-9 in alveolar macrophages, CD4-positive cells, and receptors for IL-9 in airway epithelial cells. Collectively, these data suggest that IL-9 plays an important role in the pathogenesis of lung fibrosis in diseases such as IPF.

[PREVALENCE OF FUNCTIONAL DYSPEPSIA SYMPTOMS IN PATIENTS WITH ASTHMA].

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common comorbidity among patients with asthma. In addition, functional dyspepsia (FD) is characterized by upper abdominal symptoms without organic disease manifestations. However, the prevalence of FD among patients with asthma remains uninvestigated; therefore, herein, we investigated the prevalence of dyspepsia symptoms in these patients. METHODS: We recruited 156 patients with asthma from the outpatient clinic of Teikyo University Hospital and investigated the prevalence of dyspepsia symptoms using the modified Frequency Scale for the Symptoms of GERD. Further, the relationship between dyspepsia symptoms and clinical background of asthma was also investigated. RESULTS: Certain digestive organ symptoms were exhibited by 83% of patients with asthma, dyspepsia symptoms by 44%, and reflux symptoms by 26%. The dyspepsia-dominant group showed significantly higher female ratio and numerically lower %FEV1 than the asymptomatic group. In the group with dyspepsia score >5 points, the ratio of patients undergoing step 4 asthma treatment and the ratio of those using long-acting muscarinic receptor antagonist were higher than those in the group with a score <5 points. Furthermore, endoscopic diagnosis was also made in 84 patients and the prevalence of FD was 21%. CONCLUSION: A considerable proportion of patients with asthma exhibited dyspepsia symptoms, and the asthma severity in patients with dyspepsia was higher than those in asymptomatic patients. Based on the current findings, more attention should be directed to FD, in addition to GERD, as a comorbidity of the digestive system in patients with asthma.

Triple Fracture of the Intra-Articular Second Metacarpal Head, Intra-Articular Fourth Metacarpal Base, and Ulnar Styloid of An Ice Hockey Player: A Case Report.

We present a case of simultaneous ipsilateral fractures at the intra-articular second metacarpal head, intra-articular fourth metacarpal base, and ulnar styloid. These fractures were caused by the peculiar condition of a blow to the fist during an ice hockey game; the hand was struck while it was gripping a stick. The specific combination of these fractures has not been previously reported in the literature. In this incident, axial compression force was transmitted from the second and fourth metacarpal heads while skipping the third metacarpal head to the ulnar side of the wrist via the carpometacarpal joints and carpal bones. Because each fracture exhibited only slight displacement, we used conservative treatment with good outcomes.

Leukotriene receptor antagonist attenuated airway inflammation and hyperresponsiveness in a double-stranded RNA-induced asthma exacerbation model.

BACKGROUND: Viral infections are the most common triggers of asthma exacerbation, but the key molecules involved in this process have not been fully identified. Although cysteinyl leukotrienes (cysLTs) have been postulated as the key mediators, their precise roles remain largely unclear. To investigate the roles of cysLTs in virus-induced asthma exacerbation, we developed a murine model using a viral double-stranded RNA analog, polyinosinic-polycytidylic acid (poly I:C), and analyzed the effect of leukotriene receptor antagonist (LTRA) administration. METHODS: A/J mice were immunized with ovalbumin (OVA) + alum (days 0, 28, 42, and 49), followed by intranasal challenge with OVA (phase 1: days 50-52) and poly I:C (phase 2: days 53-55). Montelukast was administered during poly I:C challenge (phase 2) in the reliever model or throughout the OVA and poly I:C challenges (phases 1 and 2) in the controller model. Airway responsiveness to acetylcholine chloride was assessed, and bronchoalveolar lavage (BAL) was performed on day 56. RESULTS: Administration of poly I:C to OVA-sensitized and -challenged mice increased the number of eosinophils and levels of IL-13, IL-9, CCL3, and CXCL1 in BAL fluid (BALF) and tended to increase airway responsiveness. Montelukast significantly attenuated the poly I:C-induced increase in the number of eosinophils and levels of IL-13, IL-9, and CCL3 in BALF and airway hyperresponsiveness in both the reliever and controller models. CONCLUSIONS: This is the first report showing that LTRA functionally suppressed the pathophysiology of a virus-induced asthma exacerbation model, suggesting the importance of cysLTs as a potential treatment target.

Allergy to formaldehyde: basophil histamine-release test is useful for diagnosis.

We describe a case of formaldehyde-induced urticaria with a positive test result for serum IgE antibody against this substance. Formaldehyde's slow protein-binding property may explain why basophil histamine-release tests using fresh formaldehyde solutions are not diagnostic, whereas the tests are useful if formaldehyde that had been stored with albumin is used.

Lateral approach is advantageous in total knee arthroplasty for valgus deformed knee.

INTRODUCTION: For the total knee arthroplasty in valgus deformed knee, superiority of the medial or lateral approach is still controversial. We compared the short-term result of two approach groups. MATERIALS AND METHODS: Forty-seven knees in rheumatoid arthritis with valgus deformity from 6° to 24° were randomly divided into two group; medial approach (24 knees) and lateral approach (24 knees). We used Scorpio NRG PS for all knees. Median postoperative periods were 43 months in both groups. We compared the surgical time, and alignment on standing radiograph, range of motion (ROM) pre/postoperatively, and degrees of soft-tissue release procedure, and lateral laxity measured by stress radiograph immediately after operation and at final follow-up. RESULT: Pre/postoperative alignment, surgical time, lateral laxity, and preoperative ROM had no significant in two groups; however, postoperative flexion was superior in lateral approach group 123.8°, 109° in medial approach group. All cases required iliotibial band (ITB) release at Gerdy's tubercle, 83 % ITB at joint level, 21 % lateral collateral ligament (LCL), 17 % popliteus tendon (PT) in medial approach group, and 88 % ITB at Gerdy's tubercle, 46 % ITB at joint level, 13 % LCL, 4 % PT in lateral approach group. DISCUSSION: In the valgus knee, lateral structures are tight. Lateral approach can directly adjust the tight structure, and also less vascular compromise to the patella than medial approach with lateral patellar release. Less invasiveness to the quadriceps muscle in lateral approach could result into better range of motion after the surgery.

Targeting of locus ceruleus noradrenergic neurons expressing human interleukin-2 receptor α-subunit in transgenic mice by a recombinant immunotoxin anti-Tac(Fv)-PE38: a study for exploring noradrenergic influence upon anxiety-like and depression-like behaviors.

The noradrenergic (NA) neurons in the locus ceruleus (LC) were ablated with a high degree of selectivity by immunotoxin-mediated neuronal targeting. Transgenic mice were used in which the human interleukin-2 receptor-α subunit (hIL-2Rα; Tac) is expressed under the promoter of dopamine ß-hydroxylase. The recombinant immunotoxin, which is composed of the Fv fragment of an anti-hIL-2Rα monoclonal antibody fused to a truncated form of Pseudomonas exotoxin [anti-Tac(Fv)-PE38], was injected bilaterally into the LC of the mouse. As a result, the LC-NA neurons disappeared almost completely, and tissue noradrenaline was depleted in brain regions that receive NA inputs from the LC. The decrement of tissue noradrenaline content was more profound compared with that in mice treated with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a neurotoxin capable of ablating axons originating from the LC-NA neurons. Mice treated with either the immunotoxin or DSP-4 presented increased anxiety-like behaviors; in contrast, only the immunotoxin-treated mice, and not the DSP-4-treated mice, showed increased depression-like behavior. The immunotoxin-mediated neuronal targeting may provide a means for further unraveling the links between the LC and pathological manifestations of neurological disorders.

The in vitro effects of advanced glycation end products on basophil functions.

BACKGROUND: Basophils are thought to play pivotal roles in the pathogenesis of allergic reactions, but their roles in inflammation associated with systemic abnormalities such as metabolic disorders remain largely unknown. Advanced glycation end products (AGEs) are potentially important substances produced in high-glucose disease conditions. In this in vitro study, we investigated whether the biological functions of human basophils can be influenced by AGEs. METHODS: We analyzed the effects of AGEs on various functions and markers of human basophils, including CD11b expression, apoptosis, degranulation, and cytokine production. RESULTS: Flow cytometric analysis indicated that the level of the receptor for AGEs (RAGE) on the surface of freshly isolated basophils was very low but was clearly upregulated by IL-3. Apoptosis of basophils was induced by high concentrations of glycated albumin. Although glycated albumin failed to affect the level of surface CD11b expression or to trigger degranulation or production of IL-4 and IL-13 in basophils, it dose-dependently induced IL-6 and IL-8 secretion. CONCLUSIONS: AGEs seem to act on human basophils; they suppress the cells' longevity but elicit secretion of inflammatory cytokines. Through these biological changes, basophils might play some roles in inflammatory conditions associated with metabolic disorders presenting elevated levels of AGEs.

Efficient strategy for controlling postoperative hemorrhage in total knee arthroplasty.

PURPOSE: The objective of the present study was to compare the intraoperative use of tranexamic acid (TNA) plus intra-articular diluted-epinephrine (DEP) with preoperative autologous blood donations and transfusions in reducing an allogeneic blood transfusion (ABT) in primary unilateral total knee arthroplasty (TKA). METHODS: Patients (n=133) treated with unilateral primary TKA were divided into three groups retrospectively: patients administered autologous blood transfusions were assigned to group A (n=51); patients administered preoperative injections of TNA and postoperative intra-articular injections of DEP were assigned to group B (n=42); and patients treated with the drain-clamp method in addition to injections of TNA and DEP were assigned to group C (n=40). The rate of avoidance of ABTs, postoperative blood loss, and complications (DVT/PE, skin problems) were examined. RESULTS: The differences among the three groups were not significant in terms of the proportion of patients requiring no ABTs (94% in group A, 93% in group B and 95% in group C, n.s.). The total blood loss calculated was 1,140±451 ml, 852±343 ml, and 850±296 ml, respectively (group B>A, group C>A, P=0.0009). The significant complications were not observed in three groups. CONCLUSION: The results of the study showed that the TNA plus DEP combination exerted a comparable effect with preoperative autologous blood transfusion in avoiding ABTs in unilateral primary TKA. Considering several problems of preoperative autologous blood donation, the use of TNA plus DEP is recommended. In addition, it is highly possible that allogeneic blood transfusions can be avoided for patients with preoperative Hb values≥10.5 using the method described in this study, and the need for preoperative autologous blood donations can be decreased.

Arthroscopic tibiotalocalcaneal arthrodesis with intramedullary nail with fins: a case series.

Arthroscopic arthrodesis of the ankle has several advantages compared with open arthrodesis, including a smaller skin incision, less damage to the soft tissue around the joint, a lower risk of skin necrosis and infection, a lower incidence of postoperative infection and swelling, and better preservation of the contour of the surface of the joint, which maintains a larger contact area between the talus and tibia. We successfully performed arthroscopic arthrodesis of the tibiotalocalcaneal joints with intramedullary nails with fins in 9 ankles of 8 patients. Solid fusion was attained in all cases, except for 1 case of nonunion at the subtalar joint. We also corrected the alignment in 1 patient with a varus deformity. The fixation was strong, even in the case of poor bone quality, such as occurs in rheumatoid arthritis. The intramedullary nails with fins allowed for appropriate compression for bone consolidation without loss of rotational stability. Arthroscopic tibiotalocalcaneal arthrodesis, a less-invasive technique than conventional open surgery, is effective treatment, especially in patients with poor skin conditions secondary to diseases such as rheumatoid arthritis and diabetes mellitus.

Maternal protein restriction induces renal AT2R promoter hypomethylation in salt-sensitive, hypertensive rats.

SCOPE: We previously demonstrated that protein restriction in utero induced salt-sensitive hypertension and changed renal levels of angiotensin type 2 receptor (AT2R) in Stroke-Prone Spontaneously Hypertensive Rat (SHRSP). Here, we investigated if this characteristic alteration of AT2R is related to AT2R DNA methylation profiles. METHODS AND RESULTS: First, we examined the relation between AT2R DNA methylation and its promoter activity in vitro. Luciferase assays revealed a negative correlation between these two variables. Next, we fed SHRSP dams and grand-dams a control 20% casein diet or a 9% casein diet during pregnancy. Adult offspring and grand-offspring were supplied either water or 1% saline solution for 2 weeks. Renal AT2R promoter DNA near the TATA-box was hypomethylated, mRNA expression was suppressed, and protein expression tended to be higher, in adult offspring of mothers fed a low casein diet. Moreover, adult grand-offspring exhibited high blood pressure after salt loading, along with suppressed transcription of AT2R mRNA and elevated translated protein. CONCLUSIONS: Under a fetal environment of protein restriction, the increase in protein expression due to hypomethylation of the AT2R promoter region occurs as a response to increased salt sensitivity, and controlling this mechanism may be important for the prevention of hypertension.

Mepolizumab decreased the levels of serum galectin-10 and eosinophil cationic protein in asthma.

BACKGROUND: Mepolizumab, a humanized antibody targeting interleukin-5, decreases the number of blood eosinophils and the frequency of exacerbation of severe asthma. Galectin-10 is a protein within the cytoplasm of eosinophils and constitutes Charcot-Leyden crystals, which promotes key features of asthma. However, the relationship between time kinetics and clinical response of eosinophil-derived molecules such as galectin-10 or eosinophil cationic protein (ECP) has not been precisely investigated. OBJECTIVE: This study aimed to clarify the precise time course of the levels of serum galectin-10 and ECP after mepolizumab treatment and to analyze the relationship between the levels of eosinophil-derived molecules and the clinical background or response to mepolizumab treatment. METHODS: This multicenter, prospective open-label study recruited 20 patients with severe eosinophilic asthma. Mepolizumab was administered every 4 weeks for 32 weeks and the levels of various biomarkers were serially analyzed. RESULTS: The serum galectin-10 and ECP significantly and rapidly decreased 4 weeks after initial administration of mepolizumab. In contrast, basophil count, fractional exhaled nitric oxide, and the serum total IgE level were unchanged during treatment. Asthma Control Questionnaire-5, Asthma Health Questionnaire-33, and Lund-Mackay scores significantly improved after mepolizumab treatment. Both high ECP and eosinophil count related to better response in forced expiratory volume in 1 second (FEV1) and measurable ECP level at 4 weeks after administration of mepolizumab related to the further improvement in FEV1 toward week 32. No significant difference in improvement in FEV1 was observed in galectin-10 high group. The level of ECP at baseline was significantly related to the higher prevalence of nasal polyp and Lund-Mackay score. CONCLUSION: This study was the first to show that the levels of serum galectin-10 decreases after initial administration of mepolizumab. The significant relationship between serum ECP and better response in FEV1 suggested the potential role of serum ECP as a predictive biomarker for the efficacy of mepolizumab (UMIN000030466).

The prevalence of comorbid respiratory disease among COVID-19 patients, and mortality during the first wave in Japan: A nationwide survey by the Japanese Respiratory Society.

There is a concern that persons with underlying respiratory disease may have increased susceptibility to COVID-19 and/or increased severity/mortality if infected. However, information regarding such patients during the first wave of the epidemic is lacking in Japan. We surveyed chest physicians nationwide, and collected anonymous data concerning 1444 patients. Among COVID-19 patients, the prevalence of asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung diseases (ILD) was 3.4%, 4.8%, and 1.5%, respectively. Among COVID-19 patients with these 3 comorbidities, exacerbation of the comorbidity occurred in 12.2%, 18.8%, and 36.4%, respectively, and mortality (6.2% overall) was 4.1%, 13.0%, and 31.8%, respectively. The prevalence of asthma among COVID-19 patients was not higher than that for the general population, and mortality in COVID-19 patients with asthma was not higher than mortality in COVID-19 patients without underlying respiratory disease. COVID-19 patients having COPD or ILD had relatively high mortality, especially for ILD.

Comprehensive analysis of allergen-specific IgE in COPD: mite-specific IgE specifically related to the diagnosis of asthma-COPD overlap.

BACKGROUND: Although the relationship between allergic sensitization and increased respiratory symptoms of chronic obstructive pulmonary disease (COPD) has been suggested, which allergen has a significant effect on COPD pathology is unclear. This study aimed to identify the specific IgE related to clinical features of COPD and the diagnosis of asthma-COPD overlap (ACO). METHODS: We recruited 76 patients with COPD and analyzed 39 IgE using panel IgE test (View Allergy 39®). ACO was diagnosed according to the Japanese Respiratory Society Guidelines. RESULTS: As for perennial aeroallergens, the positivity for moth (31.5%), Candida (23.7%), Dermatophagoides pteronyssinus (22.4%) and house dust (22.4%), and concerning pollen, Japanese cedar (35.5%) and Japanese cypress (22.2%) exceeded 20%. Only the positivity of IgE for Dermatophagoides pteronyssinus and house dust was significantly higher in ACO compared with that in non-ACO COPD. Moreover, it contributed to the diagnosis of ACO in an IgE class-dependent manner. Patients with cockroach IgE exhibited higher residual volume, whereas those with Japanese cedar IgE exhibited better diffusion capacity than negative patients. The contribution for ACO diagnosis by the receiver operating characteristic curve analysis was comparable among total IgE (cutoff value: 158 IU/mL), blood eosinophil count (234/µL), and fraction of exhaled nitric oxide (31.0 ppb). CONCLUSIONS: The prominent role of mite-specific IgE in the diagnosis and pathology of ACO and the potentially detrimental effect of cockroach sensitization on air trapping in COPD were suggested. The finding highlights the future development of a treatment targeting IgE as a treatable trait in COPD.

A case of anaphylactic reaction following matsutake mushroom ingestion: demonstration of histamine release reaction of basophils.

BACKGROUND: Matsutake mushroom is not recognized as a common food allergen. However, several case reports have suggested that this mushroom can induce anaphylaxis on rare occasions. CASE SUMMARY: We report a woman with bronchial asthma, who experienced two episodes of Matsutake-induced anaphylaxis. Both the prick-to-prick test and basophil histamine release test showed positive reactions to this mushroom in this patient, but not in control subjects. DISCUSSION: Matsutake mushroom can, on rare occasions, cause anaphylaxis in sensitized people, a reaction so far observed only in Japan. Not ony the in vivo prick-to-prick test but also the in vitro basophil activation test utilizing the patient's blood represent useful methods for allergen identification and also for identification of sensitized subjects.

QTL mapping using microsatellite linkage reveals target-site mutations associated with high levels of resistance against three mitochondrial complex II inhibitors in Tetranychus urticae.

The acaricides cyflumetofen, cyenopyrafen, and pyflubumide act as inhibitors of the mitochondrial electron transport system at complex II (succinate dehydrogenase; SDH), a new mode of action in arthropods. The development and mechanisms of low-level resistance against cyenopyrafen and cyflumetofen have been previously reported in Tetranychus urticae. In the present study, we investigated high levels of resistance against three SDH inhibitors in T. urticae field populations and clarify the genetic basis of resistance using quantitative trait locus (QTL) analysis. First, we constructed a microsatellite linkage map comprising 64 markers assembled into three linkage groups (LGs) with total length of 683.8 cM and average marker spacing of 11.03 cM. We then used the linkage map to perform QTL mapping, and identified significant QTLs contributing to resistance to cyflumetofen (one QTL on LG1), cyenopyrafen (one QTL on LG3), and pyflubumide (two QTLs on LG1 and LG3). The QTL peaks on LG1 for cyflumetofen and pyflubumide overlapped and included the SdhB locus. For cyenopyrafen resistance, the QTLs on LG3 included the SdhC locus. For cyflumetofen resistance, we found an I260T mutation in SdhB. For pyflubumide and cyenopyrafen resistance, we detected I260V and S56L substitutions in SdhB and SdhC, respectively, by direct sequencing. Both I260 in SdhB and S56 in SdhC were present in highly conserved regions of the ubiquinone binding site formed at the interface among SdhB, SdhC, and SdhD. Mutations at these positions have been implicated in resistance against fungicides that act as Sdh inhibitors in various pathogens. Therefore, we consider these mutations to be target-site resistance mutations for these acaricidal SDH inhibitors.

Plasmablastic lymphoma of the retroperitoneum in an HIV-negative patient.

Herein is reported a case of plasmablastic lymphoma (PBL) of the retroperitoneum in an HIV-negative patient. This is the first reported case of PBL at this location and of PBL from Japan in the English-language literature. A 76-year-old Japanese man was admitted to hospital with a chief complaint of right inguinal lymph node swelling. Lymph node biopsy indicated large tumor cells with both diffuse and cohesive growth patterns, and conspicuous tumor cell proliferation in lymph node sinuses. The initial pathological diagnosis was metastatic carcinoma. The patient died approximately 1 month after admission, and autopsy showed that the main lesion was a very large retroperitoneal mass. On histology diffusely proliferated plasmablast-like or immunoblast-like tumor cells were identified, which were positive on immunohistochemistry for CD138 and negative for B-cell and epithelial markers. Approximately 90% of the tumor cells were positive for Ki-67. Tumor cells were diffusely positive for EBV-encoded small RNA on in situ hybridization. The autopsy findings suggested a diagnosis of PBL. Accordingly, PBL should be considered as a differential diagnosis when lymph node biopsy findings resemble those of the present patient.