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There could be two carcinogenetic pathways for lung adenocarcinoma (LADC): the nonsmokers’ pathway and the smokers’ pathway. This review article describes the two pathways with special reference to potential relationships between histological subtypes, malignant grades, and driver mutations. The lung is composed of two different tissue units, the terminal respiratory unit (TRU) and the central airway compartment (CAC). In the nonsmokers’ pathway, LADCs develop from the TRU, and their histological appearances change from lepidic to micropapillary during the progression process. In the smokers’ pathway, LADCs develop from either the TRU or the CAC, and their histological appearances vary among cases in the middle of the progression process, but they are likely converged to acinar/solid at the end. On a molecular genetic level, the nonsmokers’ pathway is mostly driven by EGFR mutations, whereas in the smokers’ pathway, approximately one‐quarter of LADCs have KRAS mutations, but the other three‐quarters have no known driver mutations. p53 mutations are an important factor triggering the progression of both pathways, with unique molecular alterations associated with each, such as MUC21 expression and chromosome 12p13‐21 amplification in the nonsmokers’ pathway, and HNF4α expression and TTF1 mutations in the smokers’ pathway. However, investigation into the relationship between histological progression and genetic alterations is in its infancy. Tight cooperation between traditional histopathological examinations and recent molecular genetics can provide valuable insight to better understand the nature of LADCs., It has been supposed there could be two carcinogenetic pathways for lung adenocarcinoma (LADC): the nonsmokers’ pathway and the smokers’ pathway. This review article describes the two pathways with special reference to potential relationships between histological subtypes, malignant grades, and driver mutations

The cytological features of interstitial pneumonia (IP)-related lung adenocarcinoma (LADC) have not been clearly described. This study aimed to describe its cytomorphological features, uncover potential problems in practical cytological diagnosis, and provide possible solutions.Bronchial brushing cytology samples from 40 IP-related LADC cases (the IP group) and 110 control cases (LADC unrelated to IP; the non-IP group) were analyzed. All patients underwent surgery after brushing cytology, and their histopathological subtypes were determined. The authors reviewed the cytological features and focused particularly on cytoplasmic mucin production.In the IP group, neoplastic cells with cytoplasmic mucin were detected at a significantly higher frequency (44.4% [8 of 18] vs. 6.3% [4 of 64]), and most of them were invasive mucinous adenocarcinomas (IMAs). Twenty-two of the 40 LADC cases in the IP group failed to be judged as "malignant/positive" (thus, they were judged to be "equivocal and/or negative"). The frequency of equivocal and/or negative judgments was 55.0% (22 of 40) in the IP group and 41.8% (46 of 110) in the non-IP group. The cytological diagnosis of IMA was difficult because it showed only slight nuclear atypia. Therefore, the authors examined the immunocytochemical expression of hepatocyte nuclear factor 4α (HNF4α), a diagnostic marker for IMA. As a result, four of the six cases that were judged to be equivocal in the IP group showed positive signals and could be retrospectively judged as malignant/positive.The cytological diagnosis of IP-related LADC may be more difficult because of the larger proportion of IMA. Immunocytochemistry for HNF4α can be used to improve diagnostic confidence in IP-related LADC.

OBJECTIVES Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia characterized by pleural-parenchymal involvement, predominantly in the upper lobes. Unilateral upper lung field pulmonary fibrosis (upper-PF) that is radiologically consistent with PPFE reportedly develops after lung cancer surgery in the operated side and presents many clinical characteristics in common with PPFE. However, the incidence and perioperative associated factors remain unclear. METHODS All consecutive patients with lung cancer resected completely from 2008 to 2016 were investigated retrospectively. Pre-/postoperative characteristics were compared between patients with and without unilateral upper-PF. Cumulative incidence curves were estimated using competing risk analysis. RESULTS Among the 587 included patients, 25 patients (4.3%) were diagnosed as unilateral upper-PF. The 3-, 5- and 10-year cumulative incidence of unilateral upper-PF was 2.3%, 3.3% and 5.3%, respectively. In multivariable analysis, male sex, presence of a pulmonary apical cap, lobar resection and low % vital capacity (%VC CONCLUSIONS Unilateral upper-PF is an occasional but under-recognized late complication after lung cancer surgery.

Interstitial pneumonia (IP) is a major risk factor for lung adenocarcinoma (LADC). IP-related LADC predominantly develops in the bronchiolar metaplasia lining in honeycomb lesions. Kirsten rat sarcoma virus (

Pneumocyte injury is a crucial factor influencing the severity of interstitial lung disease (ILD). In this study, we investigated the potential of hepatocyte nuclear factor α (HNF4α) as an immunohistochemical marker to detect pneumocyte injury and as a prognostic marker. Surgical lung biopsy specimens were collected from 309 patients with different types of ILDs (61 idiopathic pulmonary fibrosis (IPF), 173 non-IPF, and 75 unclassifiable ILD). HNF4α expression were examined and the frequency of positive cells (per mm2 ) was calculated. HNF4α was strongly expressed in regenerating pneumocytes present on fibroblastic foci, Masson bodies/organizing alveoli. In the non-IPF and unclassifiable ILD groups, cases with high frequency expression showed significantly poorer outcome. Particularly, in the unclassifiable ILD group, the prognostic impact was more significant (death due to ILD, log-rank test, p

The present study aimed to elucidate the mechanisms underlying the histogenesis of interstitial pneumonia (IP)-related lung adenocarcinoma (LADC). We focused on the methylation of thyroid transcription factor 1 (TTF-1). The TTF-1 locus was highly methylated in IP-LADCs compared to non-IP-LADCs. Among the IP-LADCs, the non-terminal respiratory unit (TRU) LADCs showed marked hypermethylation in CpG sites in a particular intragenic region. This region was also found to be highly methylated in the IP lungs. The hierarchical dendrogram based on methylation levels divided the IP lungs into three different clusters. One of them showed a methylation profile similar to that of non-TRU LADCs. The non-TRU LADCs developed from this cluster with a significantly higher frequency. Moreover, bronchiolar metaplasia lining honeycomb/cystic lesions in IP lungs, IP-related non-TRU LADCs, and bronchiolar epithelia in healthy lungs were separately collected by microdissection and examined for methylation. Bronchiolar metaplasia showed hypermethylation, but bronchiolar epithelia did not. The methylation patterns in bronchiolar metaplasia were similar to those in non-TRU LADCs. In summary, a particular region of TTF-1 was highly methylated in IP-related non-TRU LADCs and bronchiolar metaplasia, supporting the theory that IP-related non-TRU LADCs may develop from bronchiolar metaplasia lining honeycomb/cystic lesions.

Complete resection with a clear margin is the only curative treatment for pulmonary aspergilloma. This requires a high-level technique, especially for complex aspergilloma (CA), because of patient conditions and wide dense adhesions. Fungus ball removal is used palliatively to control hemoptysis, rather than as a radical procedure, and may be performed using video-cavernoscopy as a simple and repeatable method. In this study, we examined this approach as an alternative treatment for CA. Eight cases of fungus ball removal with video-cavernoscopy (video-cavernoscopic removal) treated at our center were retrospectively reviewed. The patient characteristics and surgical outcomes were compared with those of patients treated with one-stage radical surgery. There were 8 subjects (7 males, 1 female; median age 65 years) in the video-cavernoscopic removal group and 25 subjects (19 males, 6 females; median age 56 years) in the one-stage radical surgery group. The video-cavernoscopic removal group had a higher rate of emphysematous lung (p = 0.001), a lower body mass index (p = 0.039), and a lower percent vital capacity (p = 0.027). All cases in this group had preoperative hemoptysis that ceased after the procedure. Video-cavernoscopic removal was less invasive based on a shorter operative time (p = 0.000), less blood loss (p = 0.002), and a lower Common Terminology Criteria for Adverse Events grade (p = 0.023). However, four cases in this group (50%) relapsed with a median disease-free survival period of 471.5 days. Fungus ball removal with video-cavernoscopy is a simple technique for the prevention and control of massive hemoptysis that may be an alternative treatment for CA.

The present study aimed to discern the molecular alterations involved in the progression of EGFR-mutated lung adenocarcinoma (LADC). We previously demonstrated that the micropapillary (mPAP) element is the most important histological factor for assessing malignant grades in LADCs. Therefore, mPAP and other elements were separately collected from three cases of EGFR-mutated LADC using laser capture microdissection and subjected to a comprehensive mRNA expression analysis. We focused on DYRK2 in this study because its level showed a substantial increase in EGFR-mutated LADCs with mPAP. We also immunohistochemically examined 130 tumors for the expression of DYRK2. The results confirmed a strong expression of DYRK2 in EGFR-mutated LADC with mPAP. Fluorescent in situ hybridization (FISH) analyses targeting the DYRK2 locus revealed frequent gene amplification in EGFR-mutated LADC, specifically occurring in the high-grade components, like mPAP. In summary, the results of this study suggest that DYRK2 overexpression through gene amplification is one of the molecular mechanisms responsible for promoting the progression of EGFR-mutated LADC.

Background Bronchial kinking after lung lobectomy is likely, whereas that of the intermediate bronchus after right upper lobectomy is often not recognized. The aim of this study was to examine the clinical implications of this condition. Methods One-hundred cases of right upper lobectomy for primary lung cancer were reviewed. The cases were divided into groups with intermediate (group A) and non-intermediate (group B) bronchial kinking, and the patient characteristics and postoperative outcomes were compared. The remaining lower lobe deformation was also evaluated using the angle formed by the intrathoracic tracheal line and posterior fissure on reconstructed sagittal computed tomography. Results There were 23 cases in group A which had a higher rate of bronchial calcification, older age, and female sex, whereas and smoking and pulmonary emphysema were less frequent. Three cases in group A had respiratory symptoms such as wheezing and respiratory noise, while only one case of middle lobe atelectasis was found in group B. In multivariate analysis, upper mediastinal lymph node dissection was an independent factor for non-intermediate bronchial kinking. The lower lobe was significantly more expanded in group A than in group B. Conclusions Intermediate bronchial kinking correlates with postoperative respiratory symptoms and was less likely after upper mediastinal lymph node dissection.

AIMS Proliferative activity, evaluated from the Ki-67 index, is a strong prognostic factor in lung adenocarcinoma (LADC). Here, we optimised a procedure to measure the Ki-67 index and establish the best cut-off value. METHODS AND RESULTS We examined 342 stage I LADCs for the immunohistochemical expression of Ki-67 using different antibodies, MIB1 and SP6. The results revealed the superior specificity of SP6; therefore, SP6 was used in subsequent analyses. Slides were scanned with a virtual slide system. Using software, tumour cells were counted in a whole tumour. Thereafter, the tumour was evenly subdivided into 0.25-mm2 tiles. The frequency of positive cells was counted in each tile of an invasive area or the whole tumour. We calculated the number of tumour cells required to produce a 95% confidence interval (CI) 70% and CI of

Ciliated muconodular papillary tumors (CMPTs) are a recently categorized benign or low-grade malignant neoplasm that develops in the peripheral lung. Only about 40 cases have been reported to date, and the clinicopathological characteristics have yet to be defined in detail. Here, we present four cases of CMPTs with a focus on their immunohistochemical profiles and driver gene mutations. These tumors were a papillary proliferation of a mixture of ciliated, mucous, and basal cells located in the peripheral lung. Ciliated, mucous and basal cells were positive for TTF-1 when using the clone SPT24, but negative for HNF-4α. Basal cells were positive for p40. Mucous cells in some tumors were positive for MUC5AC and MUC6. The Ki-67 index was less than 5%, and strong expression of p53 was not detected. Three of the four tumors had a BRAF (V600E) driver mutation, an EGFR (del E746-T751/S752V) driver mutation, or driver mutations in both EGFR (E709G) and KRAS (G12V). These mutation types are rare for any histological type of lung cancer. The present results confirmed that CMPT is a neoplasm with immunohistochemical features and driver gene mutations that are distinct from those of common lung tumors.

Aims Psammoma bodies are concentrically lamellated microscopic structures made of calcium. They are commonly observed in papillary carcinomas of the thyroid gland and serous papillary adenocarcinomas of the ovary, but are also occasionally detected in lung adenocarcinomas. Only one study, published in 1972, has systematically described the significance of psammoma bodies in lung adenocarcinomas. The aim of this study was to update the significance of psammoma bodies in lung adenocarcinomas from a modern perspective. Methods and results Psammoma bodies were detected in 7.2% (59/822) of the adenocarcinomas examined, among which the papillary (20.3%, 12/59) and acinar (44.1%, 26/59) histological subtypes, with the feature of a terminal respiratory unit (91.5%, 54/59), were dominant. Malignant potential (cell growth activity measured by Ki67 labelling, lymph node metastasis, and postoperative survival) did not significantly differ between adenocarcinomas with and without psammoma bodies. On the basis of cytogenetic features, adenocarcinomas with psammoma bodies were preferentially affected by tyrosine kinase inhibitor (TKI)-targetable driver mutations [EGFR (69.8%, 37/53), ALK (13.2%, 7/53), and ROS1 (1.9%, 1/53)]. Multivariate analyses confirmed that psammoma bodies may constitute an independent predictor for these mutations, particularly EGFR and ALK mutations. Conclusions Psammoma bodies may predict a favourable response of lung adenocarcinomas to TKIs.

We herein analyzed the relationships among the immunohistochemical expression of alpha-enolase (ENO1) and clinicopathological factors in order to define the significance of ENO1 in lung adenocarcinomas (ADCs). ENO1 expression was detected in most of the ADCs examined (95.8%), but not in bronchial and alveolar epithelia. ENO1 expression was typically observed in the cytoplasm among most ADCs (95.8%), but was also detected in the nucleus (56.3%). The levels were significantly higher in terminal respiratory unit (TRU) cytological subtype ADCs. Neither cytoplasmic nor nuclear expression was associated with any other clinicopathological factors including post-operative survival and growth activity. These results suggest that ENO1 is a crucial factor promoting neoplastic transformation exclusively in TRU subtype ADCs. We also investigated the potential utility of the immunohistochemical expression of ENO1 to differentiate TRU-type ADC cells from the reactive hyperplasia of pneumocytes and bronchiolar epithelial cells because difficulties are associated with discriminating these lesions in small biopsy specimens. The sensitivity and specificity of ENO1 (cytoplasmic/nuclear) were 87.5%/37.5% and 88.9%/100%, respectively, which are superior to those of p53 (18.8% and 100%). ENO1 has potential as a biomarker to assist in the histopathological detection of TRU subtype ADC cells.

Introduction Acute exacerbation of interstitial pneumonia (AE-IP) is a lethal complication after lung surgery. We conducted a prospective, multi-institutional phase II trial to assess the efficacy and safety of prophylactic measures. Method Patients with lung cancer with dorsal subpleural fibrotic changes occupying three or more segments of both lower lobes and planned anatomical lung resection were enrolled. Prior to surgery, patients received a 125-mg bolus injection of methylprednisolone and continuous intravenous infusion of sivelestat sodium hydrate (sivelestat) for 2 days. Results Sixty-nine patients were analysed. Preoperative high-resolution computed tomography (HRCT) showed 37 (53.6%) cases presented with usual interstitial pneumonia (UIP) and possible UIP pattern. There were 60 lobectomies and 9 segmentectomies. Thirty-eight cases were in clinical stage I. No adverse events associated with prophylaxis were observed. There were four cases of AE-IP (5.8%), higher than the expected 2.0%. Three of the four cases showed inconsistencies with the UIP pattern in preoperative HRCT and were pathologically diagnosed as UIP. All patients died of respiratory failure. Overall, 89.9% were diagnosed as idiopathic interstitial pneumonias; UIP was found in 48 patients (69.6%). Severe post-operative complications occurred in 11.6% of the cases. There were 35 deaths, 17 cases of lung cancer and 11 cases related to interstitial pneumonias. The overall survival rate at 3 years was 41.8% of the total and 47.2% of cases with clinical stage I. Conclusions Perioperative use of sivelestat and low-dose methylprednisolone in patients with anatomical lung resection was safe but did not prove to be a prophylactic effect for AE-IP.

In order to clarify idiopathic interstitial pneumonia (IIP)-associated lung adenocarcinoma (LADC), we herein focused on the expression profiles of mucin proteins, the most common cellular differentiation markers. The expression of the mucin (MUC) 1, MUC2, MUC3B, MUC4, MUC5AC, MUC5B, MUC6, MUC7, MUC9, and MUC21 proteins was examined immunohistochemically and their levels were semi-quantified in 80 IIP-associated LADCs and 106 non-IIP LADCs. LADCs were divided into low and high expressers based on thresholds obtained from the receiver operating characteristic (ROC) curves of each mucin protein. Low expressers of MUC1, MUC7, and MUC21 and high expressers of MUC4, MUC5AC, MUC5B, and MUC9 were dominant in the IIP group. Multivariate analyses confirmed that the correlations between mucin expression profiles and IIP-associated LADCs were independent of putative confounding factors, such as smoking, gender, histological types, and cytological types. Thus, the expression profiles of these mucin proteins significantly differed between the IIP and non-IIP groups. IIP-associated LADCs appear to have unique cellular differentiation features and they may develop through a distinct histogenetic pathway. This is the first study to demonstrate that IIP-associated LADCs have unique mucin expression profiles.

A normal counterpart and precancerous lesion that non-terminal respiratory unit (TRU) lung adenocarcinomas (LADCs) develop from have not been clarified. Non-TRU LADCs specifically express hepatocyte nuclear factor 4α (HNF4α). Thus, we have been interested in airway epithelial cells that express HNF4α as the potential precursor of non-TRU LADC. The purposes of the present study are to report the frequency and distribution of HNF4α-expressing cells at the different airway levels, and to investigate the potential significance of the expression of HNF4α in the histogenesis of non-TRU LADC with a special reference to the relationship to bronchiolar metaplasia in idiopathic interstitial pneumonia. We herein identified a minor subpopulation of epithelial cells that express HNF4α in a physiological state. This subpopulation was mainly located in the terminal bronchioles and had the appearance of ciliated cells, which were mutually exclusive from Clara cells and others that strongly expressed thyroid transcription factor 1. Furthermore, the expression of HNF4α was similar in bronchiolar metaplastic lesions and the terminal bronchioles, and some of the metaplastic lesions showed an unequivocally higher frequency and expression level of HNF4α, which was comparable to non-TRU LADC. In summary, this is the first study to describe a subpopulation of ciliated cells that express HNF4α as a potential normal counterpart for non-TRU LADCs and suggests that bronchiolar metaplastic lesions that strongly express HNF4α are a precancerous lesion for non-TRU LADCs.

We investigated the significance of MUC21 in EGFR-mutated lung adenocarcinoma (LADC). Two-hundred forty-one surgically resected LADCs (116 EGFR-mutated and 125 wild-type tumors) were examined for immunohistochemical expression of MUC21 protein. A polyclonal antibody and two monoclonal antibodies (heM21C and heM21D) that bind differentially glycosylated MUC21 epitopes were used, and MUC21 proteins detected by these antibodies were named MUC21P, MUC21C, and MUC21D, respectively. MUC21 mRNA levels were semi-quantified and classified into "high" and "low". Among the immunohistochemical expression detected by three different antibodies, high expressors tended to be related to EGFR mutations. The three varieties of the immunohistochemical expressions were related to different histological elements in the EGFR-mutated LADCs. Either MUC21P or MUC21C high expressors had a higher proportion of lepidic elements with low papillary structure and micropapillary elements. MUC21D high expressors had a significantly higher proportion of micropapillary elements (Mann-Whitney test P ≤0.0001). Furthermore, MUC21D high expressors showed high incidence of lymphatic canal invasion and lymph node metastasis (Pearson x2 test, P = 0.0021, P = 0.0125), and a significantly higher recurrence rate (5-year recurrence-free survival 50.7% vs. 73.8%, log-rank test P = 0.0495). MUC21 proteins with a specific glycosylation status may be involved in the progression of EGFR-mutated LADCs, particularly at the stage where tumors are transforming from pure lepidic to micropapillary through low papillary lepidic lesions.

Background The thymus is associated with an immunodeficient status, autoimmune disease (AD), and the common thymic tumor, thymoma. We encountered two rare thymic tumors, thymic mucosa-associated lymphoid tissue (MALT) lymphoma and localized thymic amyloidosis, both in the presence of Sjögren’s syndrome (SjS). This suggests a possible link between rare thymic tumors and SjS. Therefore, we reviewed cases of thymic tumors to examine the spectrum of these tumors in patients with AD. Methods The clinical information of thymic amyloidosis and MALT lymphoma surgically treated at Kanagawa Cardiovascular and Respiratory Center, and Yokohama City University Hospital from January 2010 to December 2019 were reviewed. The correlation between resected thymic tumors at same period and ADs were also investigated. Results There were 5 cases of thymic amyloidosis and MALT lymphoma. ALL cases had coexistent ADs (4 SjS, 1 SSc). The median age was 66 (38–76) year-old, and 4 of the patients were female. Three cases had already diagnosed as ADs before detection of tumors. Only SSc case was received preceding steroid medication. Two cases diagnosed as SjS at the same time of the operation. The median maximum tumor diameter was 70 mm. On chest computed tomography (CT), tumors contained solid part and some cystic part at various rated. Calcification was recognized with appearance of amyloid deposition. All patients were surgically treated with total thymectomy and they are alive without recurrence. At the same period, there were 163 resected thymic tumors, including amyloidosis, MALT lymphoma, thymoma, thymic cancer, neuroendocrine tumor and so on. Among them, nine patients (5.5%) had ADs. There was a correlation between ADs and thymic MALT lymphoma/amyloidosis (P

Aims To investigate the pathological features of idiopathic interstitial pneumonia (IIP) - associated pulmonary adenocarcinoma. Methods Surgically resected adenocarcinomas associated with IIP (the IIP group) and adenocarcinomas without IIP (the non-IIP group) were subjected. We here further focused on adenocarcinomas that developed in the honeycomb lesions. Adenocarcinomas in the IIP group were subdivided into two groups, one group included tumors connected to bronchiolar metaplasia in honeycomb lesions (the H-IIP group) and the other included tumors unrelated to honeycomb lesions (the NH-IIP group). Histomorphological appearance, immunohistochemical expression were compared among the H-IIP group, the NH-IIP group, and the non-IIP group. Results Most of tumor cells in the H-IIP group showed tall columnar shape that displayed similar features to proximal bronchial epithelium, while tumors in the NH-IIP group and the non-IIP group showed club-like shape that displayed similar features to respiratory bronchiole /alveolar epithelium. The cell differentiation markers, thyroid transcription factor-1 (TTF-1) and Hepatocyte nuclear factor 4 alpha (HNF- 4α), tended to be negative for TTF-1 and positive for HNF- 4α in adenocarcinomas in the H-IIP group. The frequency of EGFR mutations was significantly lower in adenocarcinomas in the H-IIP group, although the frequency of KRAS and ALK mutations did not differ among the three groups. Conclusions The IIP-associated pulmonary adenocarcinomas, especially those arising from honeycomb lesions, have distinct pathological features. This article is protected by copyright. All rights reserved.

We herein investigated the potential role of cathepsin L in lung carcinogenesis. Lung cancer cell lines and surgically resected tumors were examined for the expression of the cathepsin L protein and copy number alterations in its gene locus. Cathepsin L was stably expressed in bronchiolar epithelial cells. Neoplastic cells expressed cathepsin L at various levels, whereas its expression was completely lost in most of the lung cancer cell lines (63.6%, 7/11) examined. Furthermore, expression levels were lower in a large fraction of lung tumors (69.5%, 139/200) than in bronchiolar epithelia. The expression of cathepsin L was lost in some tumors (16.0%, 32/200). In adenocarcinomas, expression levels were significantly lower in high-grade tumors than in low-grade tumors (one-way ANOVA, P

Thymic mucosa-associated lymphoid tissue (MALT) lymphoma is rare. Sjögren's syndrome (SjS) has strong association with thymic MALT lymphoma but the exact etiology is unknown. On the other hand, SjS is characterized by the complication of various lung manifestations, including lung cysts. The mechanism for these lesions is also unknown. But the underlying SjS could result in MALT lymphoma with lung cysts. Herein, we demonstrate two surgical cases of thymic MALT lymphoma associated with multiple lung cysts and the characterization of this rare tumor. During surgery, the tumors were found to be well capsuled and had no adhesion or invasion to the surrounding tissues consistent with its characteristics of low grade malignancy. When thymic MALT lymphoma is suspected clinically, video-assisted thoracoscopic surgery might be the best approach for diagnosis. We propose that radiological findings of a thymic tumor along with lung cysts are an indication of thymic MALT lymphoma.

Contralateral tension pneumothorax during one-lung ventilation is a rare but catastrophic surgical complication. A 72-year-old Japanese male with lung cancer underwent right upper lobectomy with video-assisted thoracoscopic surgery. Despite use of various methods for maintaining oxygenation during one-lung ventilation, percutaneous oxygen saturation was unstable from the start of surgery and suddenly decreased with a drop in blood pressure. An intraoperative chest X-ray revealed a tension pneumothorax of the dependent lung. Insertion of a chest drain saved the patient's life. This case suggests that a contralateral tension pneumothorax should be considered as a possible cause when adequate oxygenation cannot be maintained during one-lung ventilation.

A 68-year-old man who was on treatment for pulmonary Mycobacterium avium complex complained a worsening of sputum. Although he archived negative sputum culture two months ago, sputum culture tests revealed the newly isolation of Mycobacterium abscessus repeatedly. Chest computed tomography showed newly-appeared extra-pulmonary mass lesion in contact with a cyst at the bottom of his right lung. From the results of contrast-enhanced magnetic resonance imaging, we first suspected loculated pleural effusion due to Mycobacterium abscessus infection. A thoracoscopic examination was performed as the right pneumothorax developed, and the pleural lesion was successfully resected and diagnosed as an intrathoracic desmoid tumor. Intrathoracic desmoid tumor is very rare, and this is the first report of a case with pulmonary Mycobacterium abscessus disease. Keywords: Desmoid, Mycobacterium abscessus, Mycobacterium avium complex

Ciliated muconodular papillary tumors (CMPTs) are a recently categorized benign or low-grade malignant neoplasm that develops in the peripheral lung. Only about 40 cases have been reported to date, and the clinicopathological characteristics have yet to be defined in detail. Here, we present four cases of CMPTs with a focus on their immunohistochemical profiles and driver gene mutations. These tumors were a papillary proliferation of a mixture of ciliated, mucous, and basal cells located in the peripheral lung. Ciliated, mucous and basal cells were positive for TTF-1 when using the clone SPT24, but negative for HNF-4α. Basal cells were positive for p40. Mucous cells in some tumors were positive for MUC5AC and MUC6. The Ki-67 index was less than 5%, and strong expression of p53 was not detected. Three of the four tumors had a BRAF (V600E) driver mutation, an EGFR (del E746-T751/S752V) driver mutation, or driver mutations in both EGFR (E709G) and KRAS (G12V). These mutation types are rare for any histological type of lung cancer. The present results confirmed that CMPT is a neoplasm with immunohistochemical features and driver gene mutations that are distinct from those of common lung tumors.

Lung adenocarcinomas (ADCs) have been roughly divided into two groups: the terminal respiratory unit (TRU) type and non-TRU type. These ADCs appear to develop through exclusive carcinogenetic pathways because of differences in their cellular morphologies and the profiles of protein expression and genetic alterations. The TRU type develops from atypical adenomatous hyperplasia as a precursor. On the other hand, the histogenesis of the non-TRU type has not yet been defined in detail. We herein investigated histopathological changes in the non-tumor lung tissues of patients with non-TRU-type ADCs in order to define their potential histogenesis. The non-TRU type preferentially occurs in patients with interstitial pneumonia, in whom tumors are located in honeycomb lesions and are associated with bronchiolar metaplasia (BM). Among patients without interstitial pneumonia, non-tumor lung tissues from non-TRU-type ADCs were often affected by multiple BM. In these cases, tumors often were associated with BM. Metaplastic cells adjacent to non-TRU-type ADCs ectopically expressed HNF-4α, a marker for non-TRU-type ADCs. These results suggest that the non-TRU type develops through distinct histogenesis, in which BM is implicated.

We herein analyzed the relationships among the immunohistochemical expression of alpha-enolase (ENO1) and clinicopathological factors in order to define the significance of ENO1 in lung adenocarcinomas (ADCs). ENO1 expression was detected in most of the ADCs examined (95.8%), but not in bronchial and alveolar epithelia. ENO1 expression was typically observed in the cytoplasm among most ADCs (95.8%), but was also detected in the nucleus (56.3%). The levels were significantly higher in terminal respiratory unit (TRU) cytological subtype ADCs. Neither cytoplasmic nor nuclear expression was associated with any other clinicopathological factors including post-operative survival and growth activity. These results suggest that ENO1 is a crucial factor promoting neoplastic transformation exclusively in TRU subtype ADCs. We also investigated the potential utility of the immunohistochemical expression of ENO1 to differentiate TRU-type ADC cells from the reactive hyperplasia of pneumocytes and bronchiolar epithelial cells because difficulties are associated with discriminating these lesions in small biopsy specimens. The sensitivity and specificity of ENO1 (cytoplasmic/nuclear) were 87.5%/37.5% and 88.9%/100%, respectively, which are superior to those of p53 (18.8% and 100%). ENO1 has potential as a biomarker to assist in the histopathological detection of TRU subtype ADC cells.

We report a 53-year-old man with metastases of alveolar soft-part sarcoma originated from the mediastinum. He was hospitalized due to lower extremities’ paralysis. Computed tomography scan findings revealed multiple nodules of bilateral lungs, swollen mediastinal lymph nodes, and osteolysis of thoracic vertebrae. We performed spinal decompression and biopsy from vertebra. And, we finally diagnosed this case as metastases of mediastinal alveolar soft-part sarcoma which was removed 10 years ago. Alveolar soft-part sarcoma is rare tumor accounted for 0.5%–1.0% of soft tissue sarcoma that often occurs primarily in the lower extremities and trunk. It is difficult to distinguish between alveolar soft-part sarcoma and paraganglioma, renal cell carcinoma and granular cell tumor morphologically. Periodic acid–Schiff stain and immunohistochemical staining of ASPL-TFE3 are useful in making a definitive diagnosis of alveolar soft-part sarcoma. This case is a rare case of alveolar soft-part sarcoma originated in the mediastinum with local recurrence and distant metastases 10 years after the initial surgery.

With the progress of antibiotic therapy, the mortality of lung abscess has been improved, and surgical intervention has declined. However, surgery is still required in selected cases that are intractable to antibiotic treatment. Video-assisted thoracoscopic surgery (VATS) is beneficial for treatment and/or diagnosis of pulmonary disease as it provides a less invasive surgical technique and reduces prolongation of post-operative recovery. However, the indication of VATS lobectomy for lung abscess is controversial as a result of particular complications, i.e. wet lung, intrapleural adhesion and ease of bleeding. We herein report a rare combination of lung abscess and osteomyelitis of mandible resulting from the same pathogen successfully treated with VATS lobectomy. We propose VATS lobectomy for lung abscess. This procedure might be the best treatment candidate for selected cases of lung abscess.

Purpose The aim of this study was to evaluate the efficacy of the Thopaz system, a new drainage system in management of general thoracic surgery, based on a review of our clinical practice and a comparison of the utility of the Thopaz device compared with a standard drainage system. Methods A review of 540 thoracic surgeries at our hospital was performed. These cases were divided into 275 treated with the Thopaz system from April 2014 to March 2015, and 265 treated with a standard system from April 2013 to March 2014. The characteristics of patients and outcomes after surgery were compared in these two groups. Results The characteristics of the patients were similar in the two groups. Outcomes after surgery, including types of operation, period of chest tube placement, chest tube reinsertion rate, and clamping test rate also did not differ significantly between the groups. Conclusions The non-inferiority of the Thopaz system compared to a standard system was verified statistically. With advantages of providing objective data as a small portable system, in addition to the quietness of the unit and the ease of setup and operation, Thopaz system is likely to become mainstream in postoperative management in general thoracic surgery. This article is protected by copyright. All rights reserved.

We herein investigated the potential role of cathepsin L in lung carcinogenesis. Lung cancer cell lines and surgically resected tumors were examined for the expression of the cathepsin L protein and copy number alterations in its gene locus. Cathepsin L was stably expressed in bronchiolar epithelial cells. Neoplastic cells expressed cathepsin L at various levels, whereas its expression was completely lost in most of the lung cancer cell lines (63.6%, 7/11) examined. Furthermore, expression levels were lower in a large fraction of lung tumors (69.5%, 139/200) than in bronchiolar epithelia. The expression of cathepsin L was lost in some tumors (16.0%, 32/200). In adenocarcinomas, expression levels were significantly lower in high-grade tumors than in low-grade tumors (one-way ANOVA, P 0.0500). Copy number alterations were found in 18.0% (36 [32 gain + 4 loss] /200) of lung tumors. No relationship existed between cathepsin L protein expression levels and the copy number of its gene locus (Spearman's rank-order correlation, P = 0.3096). Collectively, these results suggest that the down-regulated expression of cathepsin L, which is caused by an undefined mechanism other than copy number alterations, is involved in the progression of lung adenocarcinomas.

We herein analyzed the relationships between tropomyosin protein expression levels and clinicopathological factors in order to determine the significance of tropomyosins in lung cancers. Although neoplastic cells expressed different isoforms of tropomyosin, overall expression levels were lower than those in bronchial and alveolar epithelial cells. In adenocarcinomas, tropomyosin levels were markedly reduced in poorly differentiated or solid subtype carcinomas, suggesting that a loss in the expression of tropomyosins is involved in the progression of lung adenocarcinomas. The potential utility of the immunohistochemical expression of tropomyosins for a histopathological diagnosis was also investigated. The sensitivity and specificity of a loss in the expression of tropomyosins were 100% and 50%, respectively, which were superior to those for the strong expression of p53 (sensitivity 100% and specificity 44%), a conventional biomarker. An immunohistochemical examination of tropomyosins may assist in the histopathological detection of lung cancer cells in small biopsy specimens.