[Interpretation of T-cell and NK-cell lymphoid proliferations and lymphomas in the 5th edition of the WHO classification of haematolymphoid tumours].

The 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumours used the hierarchical system to classify T-cell and NK-cell lymphoid proliferations and lymphomas (T/NK-LPD/LYM) based on research advances and clinicopathological characteristics of the diseases. In this edition of classification, tumour-like lesions were included, some tumors were added/deleted, the names or terms of certain diseases were refined, and the diagnostic criteria or subtypes of some diseases were revised. This group of diseases was reintegrated from non-clonal hyperplasia to highly aggressive lymphoma, which would further reflect the nature of T/NK-LPD/LYM and benefit to clinical application.

Measurement of the

The ^{18}O(α,γ)^{22}Ne reaction is critical for AGB star nucleosynthesis due to its connection to the abundances of several key isotopes, such as ^{21}Ne and ^{22}Ne. However, the ambiguous resonance energy and spin-parity of the dominant 470 keV resonance leads to substantial uncertainty in the ^{18}O(α,γ)^{22}Ne reaction rate for the temperature of interest. We have measured the resonance energies and strengths of the low-energy resonances in ^{18}O(α,γ)^{22}Ne at the Jinping Underground Nuclear Astrophysics experimental facility (JUNA) with improved precision. The key 470 keV resonance energy has been measured to be E_{α}=474.0±1.1 keV, with such high precision achieved for the first time. The spin-parity of this resonance state is determined to be 1^{-}, removing discrepancies in the resonance strengths in earlier studies. The results significantly improve the precision of the ^{18}O(α,γ)^{22}Ne reaction rates by up to about 10 times compared with the previous data at typical AGB temperatures of 0.1-0.3 GK. We demonstrate that such improvement leads to precise ^{21}Ne abundance predictions, with an impact on probing the origin of meteoritic stardust SiC grains from AGB stars.

[Analysis of clinicopathological and molecular abnormalities of angioimmunoblastic T-cell lymphoma].

OBJECTIVE: To analyze the clinicopathological features, molecular changes and prognostic factors in angioimmunoblastic T-cell lymphoma (AITL). METHODS: Sixty-one cases AITL diagnosed by Department of Pathology of Peking University Cancer Hospital were collected with their clinical data. Morphologically, they were classified as typeⅠ[lymphoid tissue reactive hyperplasia (LRH) like]; typeⅡ[marginal zone lymphoma(MZL)like] and type Ⅲ [peripheral T-cell lymphoma, not specified (PTCL-NOS) like]. Immunohistochemical staining was used to evaluate the presence of follicular helper T-cell (TFH) phenotype, proliferation of extra germinal center (GC) follicular dendritic cells (FDCs), presence of Hodgkin and Reed-Sternberg (HRS)-like cells and large B transformation. The density of Epstein-Barr virus (EBV) + cells was counted with slides stained by Epstein-Barr virus encoded RNA (EBER) in situ hybridization on high power field (HPF). T-cell receptor / immunoglobulin gene (TCR/IG) clonality and targeted exome sequencing (TES) test were performed when necessary. SPSS 22.0 software was used for statistical analysis. RESULTS: Morphological subtype (%): 11.4% (7/61) cases were classified as type Ⅰ; 50.8% (31/61) as type Ⅱ; 37.8% (23/61) as type Ⅲ. 83.6% (51/61) cases showed classical TFH immunophenotype. With variable extra-GC FDC meshwork proliferation (median 20.0%); 23.0% (14/61) had HRS-like cells; 11.5% (7/61) with large B transformation. 42.6% (26/61) of cases with high counts of EBV. 57.9% (11/19) TCR+/IG-, 26.3% (5/19) TCR+/IG+, 10.5% (2/19) were TCR－/IG－, and 5.3% (1/19) TCR－/IG+. Mutation frequencies by TES were 66.7% (20/30) for RHOA, 23.3% (7/30) for IDH2 mutation, 80.0% (24/30) for TET2 mutation, and 33.3% (10/30) DNMT3A mutation. Integrated analysis divided into four groups: (1) IDH2 and RHOA co-mutation group (7 cases): 6 cases were type Ⅱ, 1 case was type Ⅲ; all with typical TFH phenotype; HRS-like cells and large B transformation were not found; (2) RHOA single mutation group (13 cases): 1 case was type Ⅰ, 6 cases were type Ⅱ, 6 cases were type Ⅲ; 5 cases without typical TFH phenotype; 6 cases had HRS-like cells, and 2 cases with large B transformation. Atypically, 1 case showed TCR－/IG－, 1 case with TCR－/IG+, and 1 case with TCR+/IG+; (3) TET2 and/or DNMT3A mutation alone group (7 cases): 3 cases were type Ⅱ, 4 cases were type Ⅲ, all cases were found with typical TFH phenotype; 2 cases had HRS-like cells, 2 cases with large B transformation, and atypically; (4) non-mutation group (3 cases), all were type Ⅱ, with typical TFH phenotype, with significant extra-GC FDC proliferation, without HRS-like cells and large B transformation. Atypically, 1 case was TCR－/IG－. Univariate analysis confirmed that higher density of EBV positive cell was independent adverse prognostic factors for both overall survival (OS) and progression free survival(PFS), (P=0.017 and P=0.046). CONCLUSION: Pathological diagnoses of ALTL cases with HRS-like cells, large B transformation or type Ⅰ are difficult. Although TCR/IG gene rearrangement test is helpful but still with limitation. TES involving RHOA, IDH2, TET2, DNMT3A can robustly assist in the differential diagnosis of those difficult cases. Higher density of EBV positive cells counts in tumor tissue might be an indicator for poor survival.

An unusually diverse genus of Collembola in the Cape Floristic Region characterised by substantial desiccation tolerance.

Trait-environment interactions have contributed to the remarkable plant radiations in the Cape Floristic Region (CFR) of southern Africa. Whether such interactions have also resulted in the diversification of the invertebrate fauna, independently of direct associations with plants is, however, not clear. One candidate where this may be the case is the unusually diverse Collembola genus Seira. Including 89 species in the CFR, many of which are localised habitat specialists, this genus includes many species inhabiting the warm, dry fynbos shrubland-a habitat atypical of usually desiccation-sensitive Collembola. Here, we investigate whether desiccation tolerance may have contributed to the considerable diversity of Seira in the CFR. First, we demonstrate, by measuring vapour pressure deficits (VPD) of the species' microhabitats (fynbos shrubland and moister Afrotemperate Forests), that the fynbos shrublands are dry environments (mean ± S.E. maximum VPD 5.2 ± 0.1 kPa) compared with the Afrotemperate Forest patches (0.3 ± 0.02 kPa) during the summer activity period of Seira. Then we show that Seira species living in these shrublands are more desiccation tolerant (mean ± S.E. survival time at 76% relative humidity: 74.3 ± 3.3 h) than their congeners in the cooler, moister Afrotemperate Forests (34.3 ± 2.8 h), and compared with Collembola species globally (3.7 ± 0.2 h). These results, and a previous demonstration of pronounced thermal tolerance in the fynbos shrubland species, suggest that the diversity of Seira in the CFR is at least partly due to pronounced desiccation and thermal tolerance, which has enabled species in the genus to exploit the hot and dry habitats of the CFR.

[Factors affecting intraoperative changes in regional cerebral tissue oxygen saturation in elderly patients undergoing laparoscopic hysterectomy].

Objective: To explore the factors that affect the fluctuation of intraoperative regional cerebral oxygen saturation (rSctO2) in elderly patients undergoing laparoscopic hysterectomy. Methods: A retrospective analysis of 39 elderly patients undergoing elective laparoscopic hysterectomy in Yale New Haven Hospital from October 2016 to February 2017 was performed. Factors including patients' demographic data, past medical history, intraoperative monitoring index and rSctO2 index (baseline, maximum, minimum, maximum-baseline, baseline-minimum) were recorded. Pearson correlation analysis was used to analyze the correlation between rSctO2 indexes and preoperative and intraoperative factors. Independent sample t-test was used to compare the differences of rSctO2 indexes between hypertension group and the group without hypertension, as well as diabetes group and the group without diabetes. Taking diabetes as the stratification factor, the relationship between rSctO2and factors including age, body mass index, hypertension were analyzed using multivariate analysis. Results: The age of the patients was (67.6±5.6) years old. The baseline value of rSctO2 was (71.2±3.9)% in the left frontal lobe and (70.8±4.1)% in the right frontal lobe. Results from univariate analysis showed that the left and right maximum-baseline value of rSctO2 were (12.9±4.5)% and (12.8±4.4)%, which were significantly lower than (16.3±4.2)% and (16.2±4.9)% in the group without hypertension (t=2.329, 2.266, all P<0.05). The right baseline-minimum in the group with hypertension was (5.3±3.7)%, which was significantly higher than (2.7±4.2)% in the group without hypertension (t=-2.061, P<0.05). The left minimum value of rSctO2 in diabetic group was (64.4±4.2)%, and the maximum value of rSctO2on the left and right sides were (81.7±4.0)% and (81.9±4.5)%, which were lower than (68.4±4.1)%, (86.7±4.2)% and (86.0±3.7)% in the group without diabetes (t=2.623, 3.297, 2.850, all P<0.05). The results of multivariate analysis showed the influence of age (t=2.866, P<0.05) and hypertension on left maximum-baseline (t=-4.530, P<0.01) was statistically significant. The influence of hypertension on right maximum-baseline was statistically significant (t=-4.629,P<0.01). Conclusion: Preoperative diabetes and hypertension are factors significantly affecting the intraoperative rSctO2 of elderly patients with laparoscopic hysterectomy.

Constraining the External Capture to the

The ^{12}C(α,γ)^{16}O reaction is one of the most crucial reactions in nuclear astrophysics. The E2 external capture to the ^{16}O ground state (GS) has not been emphasized in previous analyses but may make a significant contribution to the ^{12}C(α,γ)^{16}O cross section depending on the value of the GS asymptotic normalization coefficient (ANC). In the present work, we determine this ANC to be 337±45 fm^{-1/2} through the ^{12}C(^{11}B,^{7}Li)^{16}O reaction using a high-precision magnetic spectrograph. This sheds light on the existing large discrepancy of more than 2 orders of magnitude between the previously reported ANC values. Based on the new ANC, we experimentally constrain the GS external capture and show that through interference with the high energy tail of the 2^{+} subthreshold state, a substantial enhancement in the GS S_{E2}(300) factor can be obtained (70±7 keV b) compared to that of a recent review (45 keV b), resulting in an increase of the total S factor from 140 to 162 keV b, which is now in good agreement with the value obtained by reproducing supernova nucleosynthesis calculations with the solar-system abundances. This work emphasizes that the external capture contribution for the ground state transition cannot be neglected in future analyses of the ^{12}C(α,γ)^{16}O reaction.

[Analysis of risk factors for lymphoma patients dying of cardiovascular disease].

Objective: To understand and explore the risk factors of the death of lymphoma patients from cardiovascular disease. Methods: The medical records and death information of 1 173 patients with lymphoma were collected, cases that died from cardiovascular disease were screened. A binary logistic regression model was used to analyze the independent risk factors of patients with lymphoma died from cardiovascular disease. Results: Among 1 173 patients with lymphoma, 75 (6.4%) died of cardiovascular disease, including 27 cases of coronary heart disease, 25 cases of stroke, 7 cases of hypertension, 5 cases of sudden cardiac death, 4 cases of pulmonary embolism, 3 cases of heart failure, 4 cases of others. Among the patients who survived for more than 5 years, 16.1% (35/217) died of cardiovascular disease. Among those who survived for more than 10 years, 11.7% (7/60) died of cardiovascular disease. Multivariate Logistic regression analysis showed that the primary site of lymphoma (OR=0.521, P=0.039), stage (stage Ⅱ: OR=2.487, P=0.016; stage Ⅲ: OR=3.233, P=0.002) and cardiovascular toxicity in the course of diagnosis and treatment (OR=3.019, P=0.001) are independent influencing factors for the death of cardiovascular disease in patients with lymphoma. Patients whose primary sites of lymphoma were lymph nodes had lower risk of dying from cardiovascular disease, while the patients with stage Ⅱ to Ⅲ stage and cardiovascular toxicity during diagnosis and treatment had higher risk of dying from cardiovascular disease. Conclusions: Cardiovascular disease is an important factor affecting the survival of patients with lymphoma. With the extension of survival time, the risk of dying from cardiovascular disease increases significantly. The primary site, tumor stage, and cardiovascular toxicity that occur during the diagnosis and treatment may be the independent influencing factors for patients with lymphoma that die from cardiovascular disease.

[Analysis of the characteristics of second primary malignancy affecting the survival of lymphoma patients].

Objective: To analyze the characteristics of the second primary tumor affecting the survival of patients with lymphoma, and to explore the risk factors of death from the second primary tumor. Methods: The medical records and related death information of 1 173 lymphoma patients who had already died with known causes were collected. The basic causes of death and the characteristics of patients who died of the second primary tumor were analyzed. Cox regression model was used to analyze the risk factors of lymphoma patients who died of the second primary tumor. Results: Among the 1 173 patients who had died, 94 (8.0%) died of the second primary tumor, 935 (79.7%) died of the primary lymphoma and 144 (12.3%) died of other diseases. The second primary tumor accounted for 17.5% (38/217) of all causes of death in patients with the survival period of more than 5 years, and the second primary tumor accounted for 28.3% (17/60) of all causes of death in patients with the survival period of more than 10 years. Among 94 cases who died of second primary tumors, 31 died of lung cancer, 15 died of gastric cancer, 13 died of liver cancer, 9 died of pancreatic cancer, 6 died of colorectal cancer, 6 died of second primary lymphoma and 14 died of other types of tumors. Univariate Cox regression analysis showed that age, first-line treatment effect, and chest or mediastinal radiotherapy were associated with the death from second primary tumors for lymphoma patients (all P<0.05). Multivariate Cox regression analysis showed that the effect of first-line treatment (P=0.030) and the chest or mediastinal radiotherapy (P=0.039) were independent factors for the death of lymphoma patients from the second primary tumor. Conclusions: The second primary tumor is an important factor affecting the survival of lymphoma patients, and the risk of death from second primary tumors increases significantly over time. The effect of first-line treatment and radiotherapy in the chest or mediastinum are independent factors for the death of lymphoma patients from the second primary tumor.

[Analysis of clinical prognosis of 68 patients with gastric mucosa-associated lymphoid tissue lymphoma].

Objective: To explore the clinical features and prognosis of gastric mucosa-associated lymphoid tissue lymphoma. Methods: The data of patients with gastric mucosa-associated lymphoid tissue lymphoma diagnosed and treated at Peking University Cancer Hospital from 2000 to 2019 were collected, and their clinical characteristics, treatment options and effects, and prognosis were retrospectively analyzed. Results: The median age of 68 patients was 56 years old, and the ratio of men to women was 0.6∶1.0. Early patients accounted for about 76% (52/68). The most commonly used treatment is Helicobacter pylori eradication, followed by radiotherapy and chemotherapy. The total effective rate is 94%, of which the complete remission rate is 72%. With a median follow-up of 44 months, the 5-year progression-free survival (PFS) rate was 73%, and the overall survival (OS) rate was 83%. Prognostic factor analysis showed that albumin level (P=0.011) and international prognostic index (IPI)(P=0.017) are independent prognostic indicators of PFS, The 5-year PFS rate of patients with normal and reduced albumin was 77% and 50%, respectively, and the 5-year PFS rate of patients with IPI score<2 points and IPI ≥ 2 points was 80% and 48%, respectively. Lactate dehydrogenase (LDH) (P=0.016) and albumin level (P=0.025) are independent prognostic indicators of OS, and the 5-year OS rates of patients with normal and elevated LDH were 87% and 67%, respectively. The 5-year OS rates of patients with normal albumin and reduced were 92% and 73%, respectively. Conclusions: Gastric mucosa-associated lymphoid tissue lymphoma is sensitive to treatment and has a good prognosis. The patient's albumin and lactate dehydrogenase levels are independent prognostic indicators.

[Diagnostic and therapeutic values of interphase fluorescence in situ hybridization in B-cell lymphomas: a clinicopathologic analysis of 604 cases].

Objective: To investigate the feasibility and value of interphase fluorescence in situ hybridization (FISH) in the pathological diagnosis, differential diagnosis and therapeutic assessment of B-cell lymphomas. Methods: The cohort included 604 cases of B-cell lymphoma which were collected at West China Hospital from May 2010 to December 2016.And all were subjected to interphase FISH using 11 break apart or fusion probes (MYC, bcl-2, bcl-6, IRF4, MYC/IgH, bcl-2/IgH, CCND1/IgH, IgH, API2/MALT1, p53/ATM, and D13S319/CEP12). Results: The median age of the 604 B-cell lymphoma patients was 47.7 (aged 2-90) years including 372 men and 232 women. All the cases was divided into 463 large B cell lymphomas(LBL) and 141 small B cell lymphomas, and the total interphase FISH positive rate was 59.8% (361/604). Among the 463 LBL, 12.5% (58/463), 9.5% (44/463) and 2.2% (10/463) of cases showed MYC, bcl-6 and bcl-2 gene rearrangements respectively; and 363 diffuse large B cell lymphoma (DLBCLs) were reclassified as germinal center B-cell (GCB) subtype (38.6%, 140/363) and non-GCB subtype (61.4%, 223/363) by Hans algorithm. The rearrangement rates in GCB and non-GCB DLBCL were 45.7%(64/140)and 21.5%(48/223; P=0.001), respectively. Compared to the non-GCB DLBCL, GCB DLBCL showed higher MYC and bcl-2 gene rearrangements (P=0.001). Eleven (2.4%, 11/463) cases had MYC and bcl-6 or bcl-2 gene rearrangement (double-hit lymphoma); one (0.2%, 1/463) case had MYC, bcl-6 and bcl-2 gene rearrangements (triple-hit lymphoma); two (0.4%, 2/463) cases had bcl-2 and bcl-6 gene rearrangements. MYC translocation and MYC/IgH fusion were detected in 94.2%(81/86) and 83.7%(72/86) cases of Burkitt lymphomas. IRF4 rearrangement was detected in two cases of IRF4+ LBCL. Genetic abnormalities were detected in 9/19, 100%(29/29), 30.8%(12/39) and 68.5%(37/54) cases of follicular lymphoma, mantle cell lymphoma, MALT lymphoma and chronic lymphocytic leukemia, respectively. Conclusions: Interphase FISH can rapidly and accurately detect the genetic changes in B-cell lymphomas. Different genetic changes are specifically valuable to the diagnosis, differential diagnosis, prognosis evaluation and treatment guidance of various B-cell lymphomas.

[Diagnostic significance of lymph node core needle biopsy for lymphoproliferative disease: a clinicopathologic study of 1 013 cases].

Objective: To study the clinicopathologic features of lymphoproliferative disease by lymph node core needle biopsy(CNB)and to evaluate the diagnostic significance of CNB for lymphoproliferative disease. Methods: The annual distribution, entity constitute, clinical finding, gross feature, morphologic change, affiliate study and repeat biopsy diagnosis of 1 013 cases of lymph node CNB diagnosed at West China Hospital of Sichuan University from January 2009 to December 2015 were investigated. Results: (1) Proportion of lymph node CNB in total amount of biopsy specimens increased from 0.2% in 2009 to 0.8% in 2015.(2) The study cohort included 471 lymphomas, 12 atypical lymphoid hyperplasia (ALH), 136 suspected lymphomas, 372 benign lesions, and 22 cases of descriptive diagnoses. The most common types were diffuse large B cell lymphoma and T-lymphoblastic lymphoma. (3) Majority of patients were adolescents and children younger than 20 years or the elderly older than 60 years. 53.1% CNB tumor specimen consisted of ≥4 tissue cores and 40.5% were >2 cm in length. (4) 104 CNB cases with previous history of excision biopsy was included 45 carcinomas(no metastatic carcinoma was found), 32 lymphomas for treatment observation.1/14 suspicious lymphomas, 1/1 ALH and 3/22 cases benign lesions were diagnosed as lymphoma by repeat biopsy respectively. (5) 217 CNB cases were diagnosed as lymphoma by subsequent CNB (70), or subsequent excision biopsy (147) including 78.5%(73/93) suspected lymphomas, 5/7 ALH and 32.3%(20/62)benign lesions. Conclusions: Lymph node CNB has certain clinical indications, although limited for the diagnosis of lymphoproliferative disorders. Suspected lymphomas and ALH diagnosed by CNB should be followed by repeat tissue biopsy. For the benign lesions by CNB it does not rule out additional biopsy to further investigate the lesion.

Hole-conductor-free perovskite solar cells with carbon counter electrodes based on ZnO nanorod arrays.

A one dimensional nanostructure array has been considered as a successful charge transport material for perovskite solar cells (PSCs), because of its large internal surface area, superior charge collection efficiency and fast charge transport. Herein we demonstrate a ZnO nanorod (NR) array as the electron collector in a hole-conductor-free PSC with a carbon counter electrode (CE). A relatively low initial power conversion efficiency (PCE) of 5.6% was achieved using a 1 µm long ZnO NR array as an electron collector. However, by introduction of a thin TiO2 coating layer on the surface of ZnO via TiCl4 treatment, the PCE of the cell has been improved to the highest value of 8.24%. It is revealed that the performance enhancement of the ZnO/TiO2 NR based PSCs is largely attributed to the larger surface area, reduced electron combination, and superior electron transport properties.

Estimation of the genetic parameters of semen quality in Beijing-You chickens.

By estimating the genetic parameters of various semen quality traits in Beijing-You chickens, this study aims to elucidate the inheritance patterns of these traits and the correlations between them to facilitate setting up appropriate breeding strategies for enhanced semen quality. Semen samples were collected from 518 Beijing-You roosters at 43 wk of age from 3 selection lines related to meat flavor traits. Seven semen quality traits, consisting of semen volume, pH, and color, and sperm viability, motility, percent deformity, and concentration, were determined. Sizeable variations (18-24% CV) were observed for all traits, except for semen pH. The effects of semen collection time and origin of the chickens (line) were analyzed to optimize the proper models for estimating genetic parameters for each trait. The multiple-trait derivative-free restricted maximum likelihood method was used for estimating variance components. The results revealed that sperm viability, motility, and percent deformity exhibited high heritabilities (h(2) = 0.52, 0.85, and 0.60, respectively). Semen volume, semen color, and sperm concentration had moderate heritabilities (h(2) = 0.28, 0.19, and 0.12, respectively). Semen pH showed low heritability (h(2) = 0.03). Genetic and phenotypic correlations between sperm motility and viability were positive and high (rA = 0.88 and rP = 0.59). In addition, these 2 traits were genetically negatively correlated with percent deformity. This implied the possibility of reducing sperm deformity, which is difficult to measure, by indirect selection. It is concluded from this study that semen quality can be improved by selection. The traits with high variations and heritabilities such as semen volume are promising traits for selection to improve semen quality and likely reproductive performance of native chicken breeds.

Indigenous and introduced Collembola differ in desiccation resistance but not its plasticity in response to temperature.

Biological invasions have significant ecological and economic impacts. Much attention is therefore focussed on predicting establishment and invasion success. Trait-based approaches are showing much promise, but are mostly restricted to investigations of plants. Although the application of these approaches to animals is growing rapidly, it is rare for arthropods and restricted mostly to investigations of thermal tolerance. Here we study the extent to which desiccation tolerance and its phenotypic plasticity differ between introduced (nine species) and indigenous (seven species) Collembola, specifically testing predictions of the 'ideal weed' and 'phenotypic plasticity' hypotheses of invasion biology. We do so on the F2 generation of adults in a full factorial design across two temperatures, to elicit desiccation responses, for the phenotypic plasticity trials. We also determine whether basal desiccation resistance responds to thermal laboratory natural selection. We first show experimentally that acclimation to different temperatures elicits changes to cuticular structure and function that are typically associated with water balance, justifying our experimental approach. Our main findings reveal that basal desiccation resistance differs, on average, between the indigenous and introduced species, but that this difference is weaker at higher temperatures, and is driven by particular taxa, as revealed by phylogenetic generalised least squares approaches. By contrast, the extent or form of phenotypic plasticity does not differ between the two groups, with a 'hotter is better' response being most common. Beneficial acclimation is characteristic of only a single species. Laboratory natural selection had little influence on desiccation resistance over 8-12 generations, suggesting that environmental filtering rather than adaptation to new environments may be an important factor influencing Collembola invasions.

Serous effusion cytology of extranodal natural killer/T-cell lymphoma.

OBJECTIVE: Extranodal natural killer/T-cell lymphoma, nasal type (ENKTCL-N), is a rare form of lymphoma that typically occurs at extranodal sites. It is one of the most common extranodal lymphomas in China. Literature on effusions and cytological findings relating to ENKTCL-N is limited. We studied five consecutive cases of ENKTCL-N effusions collected over a 3-year period. The cytomorphological, immunocytochemical and molecular biological features were evaluated with literature review. The purpose of this study is to discuss how to diagnose ENKTCL-N cytologically in effusions. METHODS: Smears and cell block sections were reviewed for each case. Immunocytochemistry was performed on 4-µm paraffin sections. Antibodies used were as follows: cCD3 (intracytoplasmic CD3), CD45RO, surface CD3, CD20, CD79a, CD56, TIA-1, granzyme B, CD30, CD99, TdT and Ki-67. In situ hybridization for EBER1/2 (EBER-ISH) and T-cell receptor γ (TCRγ) gene rearrangement were performed for all cases. RESULTS: Large to medium-sized tumour cells with pleomorphic nuclei and coarse chromatin were found in a necrotic background in all cases. The cytoplasm of the tumour cells was scant to moderately abundant with occasional cytoplasmic projections; in Giemsa-stained smears, fine granules were present in some tumour cells. Mitotic figures were frequent. The tumour cells were all positive for CD56, granzyme B, TIA-1 and cCD3, and were negative for surface CD3, CD20 or CD79a, CD99 and TdT. The MIB index was 50-80%. Epstein-Barr virus-encoded RNA (EBER) hybridizing signals were detected for most neoplastic cells. The T-cell receptor gamma gene rearrangement analysis showed germ-line configuration, except for one case. CONCLUSIONS: Effusion cytology may be appropriate for establishing the diagnosis of ENKTCL-N, particularly for patients in whom tissue biopsy is not possible.