Diffusely distributed centrilobular micronodules and branching opacities as the main chest computed tomography manifestations in a patient with humidifier lung.

We report a 60-year-old man with humidifier lung showing diffusely distributed centrilobular micronodules and branching opacities on chest computed tomography (CT). Fever and dyspnea occurred 2 months after using an ultrasonic humidifier. KL-6 and SP-D were within normal ranges. Bronchoalveolar lavage showed elevated lymphocytes (53 %) and histological findings of transbronchial lung biopsy demonstrated organizing pneumonia. His condition improved after cessation of the humidifier. A provocation test exhibited a positive response to the humidifier. Humidifier lung should be considered as a differential diagnosis in patients with these CT findings. Detailed clinical, pathological and microbiological examinations are needed to exclude other diseases.

Association of the lung immune prognostic index with the survival of patients with idiopathic interstitial pneumonias.

BACKGROUND AND OBJECTIVE: The lung immune prognostic index (LIPI), a simple index calculated from the blood lactate dehydrogenase level and derived neutrophil-to-lymphocyte ratio, is thought to be associated with host immune status. However, the utility of LIPI in patients with idiopathic interstitial pneumonias (IIPs) is unknown. METHODS: In this multicentre, retrospective, observational study, an association between LIPI and the survival of patients with IIPs was evaluated. RESULTS: Exploratory and validation cohorts consisting of 460 and 414 patients with IIPs, respectively, were included (159 and 159 patients had idiopathic pulmonary fibrosis [IPF], and 301 and 255 had non-IPF, respectively). In the exploratory cohort, patients with IPF and a low LIPI had significantly better survival than those with a high LIPI (median of 5.6 years vs. 3.9 years, p = 0.016). The predictive ability of LIPI for the survival of patients with IPF was validated in the validation cohort (median of 8.5 years vs. 4.4 years, p = 0.003). In a multivariate Cox proportional hazard analysis, LIPI was selected as an independent predictive factor for the survival of IPF patients. There was no significant association between LIPI and survival of non-IPF patients in the exploratory and validation cohorts. CONCLUSION: The LIPI was a predictive factor for the survival of patients with IPF and could aid the management of IPF.

A case of severe thrombocytopenia after the first exposure to rifampicin.

Severe immune thrombocytopenia is a rare side-effect of rifampicin (RFP) and can be life-threatening. Here, we report the case of a 74-year-old male with tuberculous pleurisy who developed severe thrombocytopenia after first exposure to RFP. Platelet count decreased to 1 × 103/µL after 7 days of treatment with RFP, isoniazid, ethambutol, and pyrazinamide. After all the drugs were discontinued, the platelet count recovered. As thrombocytopenia did not occur after re-administration of drugs other than RFP, the patient was diagnosed with RFP-induced thrombocytopenia. Clinicians should be aware that RFP can induce acute and severe thrombocytopenia even without previous exposure to this drug.

A predictive model for acute exacerbation of idiopathic interstitial pneumonias.

BACKGROUND: Acute exacerbation of idiopathic interstitial pneumonias (AE-IIPs) induces permanent pulmonary dysfunction and is potentially lethal. The unpredictable occurrence of AE-IIPs remains an important clinical issue in the management of IIPs. METHODS: In this multicentre, retrospective, observational study, a predictive score for AE-IIPs was designed using clinical factors based on multivariate Fine-Gray analysis in patients with IIPs. RESULTS: Based on multivariate Fine-Gray analysis in an exploratory cohort of 487 patients with IIPs, the predictive score for AE-IIPs was determined as follows: 1 point each was added for honeycombing on high-resolution computed tomography (H), age >75 years (A) and lactate dehydrogenase level >222 U·L-1 (L); the total score ranged from 0 to 3 (HAL score). The HAL score discriminated the risk of AE-IIPs with a C-index of 0.62 (95% CI 0.56-0.67); this discrimination was verified in a validation cohort of 402 patients with IIPs with a C-index of 0.67 (95% CI 0.60-0.73). In a combined cohort, the estimated cumulative risks for AE-IIPs at 1, 2, 3, 5 and 10 years were 1.9%, 3.5%, 5.1%, 7.7% and 12.9%, respectively, in the total score 0 group; 4.7%, 8.3%, 12.0%, 17.7% and 28.4%, respectively, in the total score 1 group; and 8.0%, 14.2%, 19.7%, 28.7% and 43.0%, respectively, in the total score ≥2 group. Subgroup analysis revealed that the HAL score was applicable to patients with and without idiopathic pulmonary fibrosis. CONCLUSIONS: The HAL score discriminated the risk of AE-IIPs and could aid in the management of IIPs.

Chemotherapy for patients with advanced lung cancer with interstitial lung disease: a prospective observational study.

Introduction: Although recent advances in chemotherapy for lung cancer are remarkable, most clinical trials have excluded patients with interstitial lung disease (ILD) due to the concern of developing acute exacerbation (AE) of ILD. Hence, accumulating original evidence of cancer treatment for this population is important. Methods: Between 2016 and 2020, a prospective observational study was conducted across 11 Japanese hospitals. Patients with chemotherapy-naïve, inoperable, advanced lung cancer with ILD were included. The primary outcome was the frequency of AE-ILD after registration; the secondary outcomes were the risk factor of AE-ILD and the efficacy of chemotherapy. Results: Among 124 patients enrolled, 109 patients who received chemotherapy were analyzed. The median age was 72 years, and the majority showed usual interstitial pneumonia (UIP)/probable UIP pattern upon chest computed tomography. The median percent-predicted forced vital capacity (%FVC) was 81% (interquartile range: 66-95%). After registration, 23 patients (21.1%; 95% confidence interval [CI]: 14.4-29.7%) developed AE-ILD. The logistic analysis revealed that lower %FVC slightly but significantly increased the risk of AE-ILD (odds ratio per 10% decrease: 1.27; 95% CI: > 1.00-1.62). Overall response rates/median overall survival times in non-small-cell lung cancer and small-cell lung cancer for the first-line chemotherapy were 41% (95% CI: 31-53)/8.9 months (95% CI: 7.6-11.8) and 91% (95% CI: 76-98)/12.2 months (95% CI: 9.2-14.5), respectively. Conclusion: AE-ILD during chemotherapy is a frequent complication among patients with lung cancer with ILD, particularly those with lower %FVC. Conversely, even in this population, passable treatment response can be expected.

Transient leukocytopenia following combination therapy for COVID-19.

BACKGROUND: Combination therapy with dexamethasone, remdesivir, and baricitinib has become a promising treatment for moderate or severe COVID-19; however, we have observed transient leukocytopenia in COVID-19 patients who received combination therapy. METHODS: Twelve consecutive COVID-19 patients treated with combination therapy were included in this retrospective analysis. Blood cell counts collected at the following three time points were analyzed: before the start of therapy (period 1), within 24 h of starting therapy (period 2), and within 48 h of period 2 (period 3). RESULTS: The leukocyte count significantly decreased in period 2 compared to period 1 and then significantly increased in period 3 without withdrawal of baricitinib. The neutrophil count transiently decreased in period 2 and recovered in period 3. CONCLUSIONS: Clinicians should be aware of transient leukocytopenia in patients with COVID-19 during the early phase of combination therapy.

Metformin reduces pleural fibroelastosis by inhibition of extracellular matrix production induced by CD90-positive myofibroblasts.

Metformin, an AMP-activated protein kinase activator used to treat diabetes mellitus, has recently attracted attention as a promising anti-fibrotic agent. However, its anti-fibrotic effects on pleural fibroelastosis remain unknown. We induced mouse pleural fibroelastosis by intra-pleural coadministration of bleomycin and carbon and evaluated its validity as a preclinical model for human pleural fibrosis. We assessed the expression of the myofibroblast surface marker CD90 in the fibrotic pleura and the effects of metformin in vivo and in vitro. Finally, we evaluated the effects of metformin on human pleural mesothelial cells stimulated by transforming growth factor ß1 (TGFß1). The fibrotic pleura in mice had collagen and elastin fiber deposition similar to that seen in human fibrotic pleura. Moreover, CD90-positive myofibroblasts were detected in and successfully isolated from the fibrotic pleura. Metformin significantly suppressed the deposition of collagen and elastic fibers in the fibrotic pleura and decreased the expression of extracellular matrix (ECM)-related genes, including Col1a1, Col3a1, Fn1, and Eln, in pleural CD90-positive myofibroblasts. In human pleural mesothelial cells, metformin decreased TGFß1-induced upregulation of ECM-related genes and SNAI1. Overall, metformin suppresses pleural fibroelastosis by inhibition of ECM production by pleural myofibroblasts, suggesting that this drug has therapeutic potential against human pleural fibrosis, including pleuroparenchymal fibroelastosis.

Simple method for detecting idiopathic interstitial pneumonias by measuring vertical lung length on chest X-ray.

Detection of idiopathic interstitial pneumonias (IIPs) on chest X-ray is difficult for non-specialist physicians, especially in patients with mild IIPs. The current study aimed to evaluate the usefulness of a simple method for detecting IIPs by measuring vertical lung length (VLL) in chest X-rays to quantify decreased lung volume. A total of 280 consecutive patients with IIPs were randomly allocated to exploratory and validation cohorts, and 140 controls were selected for each cohort by propensity score-matching. Upper (uVLL; from apex to tracheal carina), lower (lVLL; from carina to costophrenic angle), and total VLL (tVLL; from apex to costophrenic angle), and the l/uVLL ratio were measured on chest X-rays. Patients in the exploratory cohort had significantly decreased uVLL, lVLL, tVLL, and l/uVLL ratio compared with controls (all p < 0.001). Receiver operating characteristic curve analyses demonstrated that lVLL (area under the curve [AUC] 0.86, sensitivity 0.65, specificity 0.92), tVLL (AUC 0.83, sensitivity 0.75, specificity 0.80), and l/uVLL ratio (AUC 0.80, sensitivity 0.72, specificity 0.79) had high diagnostic accuracies for IIPs. These results were reproduced in the validation cohort. IIP patients thus have decreased VLLs, and measurements of VLL may thus aid the accurate detection of IIPs.

Difference in the distribution of tumor-infiltrating CD8+ T cells and FOXP3+ T cells between micronodular thymoma with lymphoid stroma and micronodular thymic carcinoma with lymphoid stroma.

Micronodular thymoma with lymphoid stroma (MNT) is a rare thymic epithelial neoplasm subtype characterized by a micronodular tumor cell growth pattern and abundant lymphoid stroma. Micronodular thymic carcinoma with lymphoid stroma (MNCA) is considered as a malignant counterpart of MNT and exhibits a growth pattern similar to that of MNT but has histologic features reminiscent of thymic squamous cell carcinoma, such as cytologic atypia and CD5 and CD117 immunoexpression. Although both MNT and MNCA are characterized by abundant lymphoid stroma, it remains unknown whether there are differences in infiltrating lymphocytes between MNT and MNCA. We analyzed the immune microenvironment profile in eight MNT and three MNCA cases. The cell density of CD8-positive T cells was significantly higher in MNT than in MNCA, whereas that of FOXP3-positive T cells was significantly higher in MNCA than in MNT. There was no significant difference in the cell density of programmed death protein 1-positive T cells and programmed death ligand 1 expression between the MNT and MNCA cases. Our findings indicated that the immune microenvironment of MNCA differed from that of MNT and, compared with the T-cell profile of MNT, that of MNCA was more suppressive to patients' antitumor immune response.

Gremlin-1 for the Differential Diagnosis of Idiopathic Pulmonary Fibrosis Versus Other Interstitial Lung Diseases: A Clinical and Pathophysiological Analysis.

PURPOSE: The differential diagnosis of interstitial lung diseases (ILDs), particularly idiopathic pulmonary fibrosis (IPF) versus other non-IPF ILDs, is important for selecting the appropriate treatment. This retrospective study aimed to explore the utility of gremlin-1 for the differential diagnosis. METHODS: Serum gremlin-1 concentrations were measured using an ELISA in 50 patients with IPF, 42 patients with non-IPF ILD, and 30 healthy controls. The baseline clinical data, including pulmonary functions, prognosis, and three serum biomarkers (Krebs von den Lungen-6 [KL6], surfactant protein-D [SP-D], and lactate dehydrogenase [LDH]), were obtained through a medical record review for analyzing their associations with serum gremlin-1 concentrations. To evaluate the origin of gremlin-1, we performed immunostaining on lung sections. RESULTS: Serum gremlin-1 concentrations were significantly higher in patients with IPF (mean concentration, 14.4 ng/mL), followed by those with non-IPF ILD (8.8 ng/mL) and healthy controls (1.6 ng/mL). The area under the curve for IPF versus non-IPF ILDs was 0.759 (95% confidence interval, 0.661-0.857), which was superior to that of KL6/SP-D/LDH. The sensitivity and specificity for gremlin-1 (cutoff, 10.4 ng/mL) was 72 and 69%, respectively. By contrast, serum gremlin-1 concentrations were not associated with the pulmonary functions nor the prognosis in all patients with ILDs. In immunostaining, the gremlin-1 was broadly upregulated in IPF lungs, particularly at myofibroblasts, bronchiolar/alveolar epithelium, and CD163-positive M2-like macrophages. CONCLUSIONS: Gremlin-1 may be a useful biomarker to improve the diagnostic accuracy for IPF compared to non-IPF ILDs, suggesting a role of this molecule in the pathogenesis of IPF.

Cluster analysis-based clinical phenotypes of idiopathic interstitial pneumonias: associations with acute exacerbation and overall survival.

BACKGROUND: The precise classification of idiopathic interstitial pneumonia (IIP) is essential for selecting treatment as well as estimating clinical outcomes; however, this is sometimes difficult in clinical practice. Therefore, cluster analysis was used to identify the clinical phenotypes of IIPs, and its usefulness for predicting clinical outcomes was evaluated. METHODS: Cluster analysis was performed using clinical features including patients' demographics; histories; pulmonary function test data; and laboratory, physical and radiological findings. RESULTS: In 337 patients with IIPs, four clusters were identified: Cluster I, in which > 80% of the patients had autoimmune features; Cluster II, which had the lowest rate of smoking, the lowest percent predicted forced vital capacity (%FVC) and the lowest body mass index (BMI); Cluster III, which had the highest rate of smoking, the highest rate of dust exposure, the second lowest %FVC and normal BMI; and Cluster IV, which exhibited maintenance of %FVC and normal BMI. Cluster IV had significantly longer overall survival than Clusters II and III. Clusters I and III had significantly longer overall survival than Cluster II. Clusters II and III had a significantly higher cumulative incidence of acute exacerbation than Cluster IV. CONCLUSION: Cluster analysis using clinical features identified four clinical phenotypes of IIPs, which may be useful for predicting the risk of acute exacerbation and overall survival.

Erlotinib and bevacizumab in elderly patients ≥75 years old with non-small cell lung cancer harboring epidermal growth factor receptor mutations.

The efficacy and safety of combination therapy with erlotinib and bevacizumab in elderly patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) gene mutations are unknown. Elderly patients aged ≥75 years old with advanced or recurrent NSCLC and EGFR mutations (exon 19 deletion or L858R mutation in exon 21) received erlotinib (150 mg, daily) and bevacizumab (15 mg/kg on day 1 of a 21-day cycle) until disease progression or the occurrence of unacceptable toxicities. The primary endpoint was progression-free survival from enrollment. Twenty-five patients were enrolled in this study, and the median age was 80 years. Fifteen (60.0%) and 10 patients (40.0%) had exon 21 L858R mutations and exon 19 deletions, respectively. The median progression-free survival from enrollment was 12.6 months [95% confidence interval (CI): 8.0-33.7 months]. The objective response rate was 88.0% [95% CI: 74.0%-99.0%], and the disease control rate was 100% [95% CI: 88.7%-100%]. Grade 3 or higher adverse events occurred in 12 patients (48.0%), and rash and nausea were the most common. Grade 3 or higher bevacizumab-related toxicities occurred in 4 (16.0%) patients, including proteinuria (n = 2), gastrointestinal perforation (n = 1) and pneumothorax (n = 1). A dose reduction of erlotinib and cessation of bevacizumab was required in 16 (64.0%) and 18 patients (72.0%), respectively. Erlotinib and bevacizumab combination therapy showed a minimal survival benefit with frequent dose reductions and/or treatment discontinuations in elderly patients with EGFR-positive NSCLC.

CD248 and integrin alpha-8 are candidate markers for differentiating lung fibroblast subtypes.

BACKGROUND: Lung fibrosis is a serious life-threatening condition whose manifestation varies according to the localization and characteristics of fibroblasts, which are considered heterogeneous. Therefore, to better understand the pathology and improve diagnosis and treatment of this disease, it is necessary to elucidate the nature of this heterogeneity and identify markers for the accurate classification of human lung fibroblast subtypes. METHODS: We characterized distinct mouse lung fibroblast subpopulations isolated by fluorescence-activated cell sorting (FACS) and performed microarray analysis to identify molecular markers that could be useful for human lung fibroblast classification. Based on the expression of these markers, we evaluated the fibroblast-like cell subtype localization in normal human lung samples and lung samples from patients with idiopathic pulmonary fibrosis (IPF). RESULTS: Mouse lung fibroblasts were classified into Sca-1high fibroblasts and Sca-1low fibroblasts by in vitro biological analyses. Through microarray analysis, we demonstrated CD248 and integrin alpha-8 (ITGA8) as cell surface markers for Sca-1high fibroblasts and Sca-1low fibroblasts, respectively. In mouse lungs, Sca-1high fibroblasts and Sca-1low fibroblasts were localized in the collagen fiber-rich connective tissue and elastic fiber-rich connective tissue, respectively. In normal human lungs and IPF lungs, two corresponding major fibroblast-like cell subtypes were identified: CD248highITGA8low fibroblast-like cells and CD248lowITGA8high fibroblast-like cells, localized in the collagen fiber-rich connective tissue and in the elastic fiber-rich connective tissue, respectively. CONCLUSION: CD248highITGA8low fibroblast-like cells and CD248lowITGA8high fibroblast-like cells were localized in an almost exclusive manner in human lung specimens. This human lung fibroblast classification using two cell surface markers may be helpful for further detailed investigations of the functions of lung fibroblast subtypes, which can provide new insights into lung development and the pathological processes underlying fibrotic lung diseases.

Synchronous Occurrence of Bazex Syndrome and Remitting Seronegative Symmetrical Synovitis with Pitting Edema Syndrome in a Patient with Lung Cancer.

A 69-year-old man developed bilateral polyarthritis, edematous extremities, and skin desquamation on the fingers and ears. He did not meet the criteria for any connective tissue disease, including rheumatoid arthritis. An examination revealed advanced lung cancer. His systemic manifestations were attributed to paraneoplastic Bazex syndrome and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome. Treatment with pembrolizumab (an anti-programmed death-1 antibody) for lung cancer relieved his symptoms and shrank the lung tumor. Bazex and RS3PE syndromes are rare paraneoplastic diseases. We herein report this unique case of synchronous development of these two paraneoplastic syndromes in the presence of advanced lung cancer.

Effect of eicosapentaenoic acid on prevention of lean body mass depletion in patients with exacerbation of chronic obstructive pulmonary disease: A prospective randomized controlled trial.

BACKGROUND & AIMS: Systemic inflammation plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD), resulting in depletion of lean body mass (LBM) and muscle mass. Both frequent exacerbation of COPD and low LBM are associated with poor prognosis. This study aimed to evaluate whether supplementation of eicosapentaenoic acid (EPA) prevents depletion of LBM and muscle mass in hospitalized patients with exacerbation of COPD. METHODS: This was a prospective randomized controlled trial, conducted between November 2014 and October 2017. Fifty patients were randomly assigned to receive 1 g/day of EPA-enriched oral nutrition supplementation (ONS) (EPA group) or EPA-free ONS of similar energy (control group) during hospitalization. The LBM index (LBMI) and the skeletal muscle mass index (SMI) were measured using a bioelectrical impedance analyzer at the time of admission and at the time of discharge. Patients underwent pulmonary rehabilitation and wore a pedometer to measure step counts and physical activity. RESULTS: Forty-five patients that completed the experiment were analyzed. Baseline characteristics were similar between the EPA (n = 24) and control groups (n = 21). There were no significant differences in energy intake, step counts, physical activity, or length of hospitalization between the two groups. Although the plasma levels of EPA significantly increased only in the EPA group, we found an insignificant increase in LBMI and SMI in the EPA group compared with the control group (LBMI: +0.35 vs. +0.19 kg/m2, P = 0.60, and SMI: +0.2 vs. -0.3 kg/m2, P = 0.17, respectively). The change in the SMI was significantly correlated with the length of hospitalization in the EPA group, but not in the control group (r = 0.53, P = 0.008, and r = -0.09, P = 0.70, respectively). CONCLUSIONS: EPA-enriched ONS in patients with exacerbation of COPD during short-time hospitalization had no significant advantage in preservation of LBM and muscle mass compared with EPA-free ONS. EPA supplementation for a longer duration might play an important role in the recovery of skeletal muscle mass after exacerbation of COPD.

LTBP2 is secreted from lung myofibroblasts and is a potential biomarker for idiopathic pulmonary fibrosis.

Although differentiation of lung fibroblasts into α-smooth muscle actin (αSMA)-positive myofibroblasts is important in the progression of idiopathic pulmonary fibrosis (IPF), few biomarkers reflecting the fibrotic process have been discovered. We performed microarray analyses between FACS-sorted steady-state fibroblasts (lineage (CD45, TER-119, CD324, CD31, LYVE-1, and CD146)-negative and PDGFRα-positive cells) from untreated mouse lungs and myofibroblasts (lineage-negative, Sca-1-negative, and CD49e-positive cells) from bleomycin-treated mouse lungs. Amongst several genes up-regulated in the FACS-sorted myofibroblasts, we focussed on Ltbp2, the gene encoding latent transforming growth factor-ß (TGF-ß) binding protein-2 (LTBP2), because of the signal similarity to Acta2, which encodes αSMA, in the clustering analysis. The up-regulation was reproduced at the mRNA and protein levels in human lung myofibroblasts induced by TGF-ß1. LTBP2 staining in IPF lungs was broadly positive in the fibrotic interstitium, mainly as an extracellular matrix (ECM) protein; however, some of the αSMA-positive myofibroblasts were also stained. Serum LTBP2 concentrations, evaluated using ELISA, in IPF patients were significantly higher than those in healthy volunteers (mean: 21.4 compared with 12.4 ng/ml) and showed a negative correlation with % predicted forced vital capacity (r = -0.369). The Cox hazard model demonstrated that serum LTBP2 could predict the prognosis of IPF patients (hazard ratio for death by respiratory events: 1.040, 95% confidence interval: 1.026-1.054), which was validated using the bootstrap method with 1000-fold replication. LTBP2 is a potential prognostic blood biomarker that may reflect the level of differentiation of lung fibroblasts into myofibroblasts in IPF.

Bronchodilator Effect of Tiotropium via Respimat®Administered with a Spacer in Patients with Chronic Obstructive Pulmonary Disease (COPD).

Objective Among elderly patients with chronic obstructive pulmonary disease (COPD), there are some patients who cannot inhale tiotropium via Respimat® due to poor hand-lung coordination. This study aimed to examine whether or not tiotropium inhalation therapy using Respimat® with a spacer increased the forced expiratory volume in 1 s (FEV1) in patients with COPD. Methods A randomized, crossover, single-center study was conducted in 18 patients with stable COPD. Tiotropium (5 µg) via Respimat® with or without a spacer (AeroChamber®) was administered for 2 weeks. Following a 2-week washout period using a transdermal tulobuterol patch (2 mg per day), participants were then crossed over to the other inhalation therapy with respect to spacer use. The trough FEV1 was measured at every visit using a spirometer. A questionnaire regarding inhalation therapy was administered to patients at the final visit. Results The administration of tiotropium via Respimat® both with and without a spacer significantly increased the trough FEV1 from baseline during each treatment period, with mean differences of 115.0±169.6 mL and 92.8±128.1 mL, respectively. There was no significant difference in the change in the trough FEV1 between the 2 procedures (p=0.66). A total of 86% of patients reported that inhalation using a spacer was not difficult, and more than half also rated both the usage and maintenance of the AeroChamber® as easy. Conclusion Tiotropium inhalation therapy administered via Respimat® using a spacer exerted a bronchodilatory effect similar to that observed with tiotropium Respimat® alone.

Cytological Features of a Variant NUT Midline Carcinoma of the Lung Harboring the NSD3-NUT Fusion Gene: A Case Report and Literature Review.

Background. Nuclear protein in testis (NUT) midline carcinoma (NMC) is a very rare and aggressive malignancy. In more than two-thirds of these NMC cases, a fusion between NUT and BRD4 or BRD3 has been documented; other variants are rare. The cytology of NMC itself has been sparsely documented and that of variant NMC has never been reported. Case Presentation. A 36-year-old woman was admitted because of a rapidly progressing lung tumor with metastases to the breast and bone. We recently reported this patient as the first case of a variant NMC of the lung harboring an NSD3-NUT fusion, based on immunohistochemical and genetic analyses. Cytological material was available for the present review. A highly cellular smear contained a predominantly noncohesive pattern of monomorphic cells with diameters 2-2.5 times greater than those of small lymphocytes, with a round-to-oval nucleus, slightly irregular nuclear contours, variably prominent nucleoli, scant cytoplasm, and identifiable mitotic figures. Foci of stratification and overt pearl formation, including a dyskeratocyte, were occasionally observed. The necrotic background contained naked nuclei, karyorrhectic debris, apoptotic cells, and macrophages phagocytizing karyorrhectic debris; nuclear crushing was noted. Conclusion. The cytological features of a variant NMC of the lung are described for the first time.

NSD3-NUT-expressing midline carcinoma of the lung: first characterization of primary cancer tissue.

BACKGROUND: Nuclear protein in testis (NUT) midline carcinoma (NMC) is a rare, aggressive malignancy. Only two pediatric and three adult cases of pulmonary NMCs have been documented. In more than two-thirds of NMC cases, a gene fusion between NUT and BRD4 or BRD3 has been documented; other fusions are rare. CASE PRESENTATION: A 36-year-old woman was admitted because of a rapidly progressing tumor of the lung with metastases to the breast and bone. A biopsy from the lung tumor revealed an undifferentiated neoplasm exhibiting round to oval nuclei with vesicular chromatin, prominent nucleoli, and scant cytoplasm. Immunohistochemical staining demonstrated focal EMA, cytokeratin AE1/AE3, cytokeratin CAM 5.2, p63, CD138, and vimentin positivity. Finally, the nuclear staining pattern for NUT confirmed a histopathological diagnosis of NMC. A 5'- rapid amplification of the cDNA end (RACE) procedure successfully identified the partner of the NUT translocation as NSD3, a recently discovered partner. Fluorescence in situ hybridization confirmed the NSD3-NUT gene rearrangement, whereas a BRD3/4-NUT fusion gene was not detected. CONCLUSION: We herein describe the first case of an NSD3-NUT-expressing NMC of the lung. The further accumulation of variant NMCs should provide clues to the establishment of new individualized therapy for NMCs.