Micropapillary and solid components as high-grade patterns in IASLC grading system of lung adenocarcinoma: Clinical implications and management.

OBJECTIVES: The grading system proposed by the International Association for the Study of Lung Cancer is based on a combination of predominant histologic subtypes and the proportion of high-grade components with a cutoff of 20%. We aimed to examine the clinical implications of the grading system beyond the discrimination of patient prognosis, while assessing the biological differences among high-grade subtypes. METHODS: We retrospectively reviewed 648 consecutive patients with resected lung adenocarcinomas and examined their clinicopathologic, genotypic, and immunophenotypic features and treatment outcomes. Besides the differences among grades, the clinical impact of different high-grade components: micropapillary (MIP) and solid (SOL) patterns, was individually evaluated. RESULTS: Survival outcomes were well-stratified according to the grading system. Grade 3 tumors exhibited aggressive clinicopathologic features, while being an independent prognostic factor in multivariable analysis. A small proportion (<20 %) of high-grade components in grade 2 had a negative prognostic impact. The prognostic difference bordering on the 20 % cutoff of the MIP proportion was validated; however, the proportion of SOL component did not affect prognosis. A survival benefit from adjuvant chemotherapy was observed in grade 3 tumors regardless of histologic subtype, but not in grade 1-2 tumors. The molecular and immunophenotypic features were different among grades, but still heterogeneous in grade 3, with MIP harboring frequent EGFR mutation and SOL exhibiting high PD-L1 expression. The treatment outcome after recurrence was worse in grade 3, but tumors with MIP pattern had an equivalent prognosis to that of grade 1-2 tumors, reflecting the high frequency of molecular targeted therapy. CONCLUSIONS: In addition to stratifying patient prognosis, the current grading system could discriminate clinical course, therapeutic effects of adjuvant chemotherapy, and molecular and immunophenotypic features. Further stratification based on biological heterogeneity in grade 3 remains necessary to enhance the role of the grading system in guiding patient management.

Prognostic implications of prostaglandin E-major urinary metabolite in resected non-small-cell lung cancer.

OBJECTIVES: Cyclooxygenase-2-derived prostaglandin E2 (PGE2) is highly involved in the promotion of cancer progression. The end product of this pathway, PGE-major urinary metabolite (PGE-MUM), is a stable metabolite of PGE2 that can be assessed non-invasively and repeatedly in urine samples. The aim of this study was to assess the dynamic changes in perioperative PGE-MUM levels and their prognostic significance in non-small-cell lung cancer (NSCLC). METHODS: Between December 2012 and March 2017, 211 patients who underwent complete resection for NSCLC were analysed prospectively. PGE-MUM levels in 2 spot urine samples taken 1 or 2 days preoperatively and 3-6 weeks postoperatively were measured using a radioimmunoassay kit. RESULTS: Elevated preoperative PGE-MUM levels were associated with tumour size, pleural invasion and advanced stage. Multivariable analysis revealed that age, pleural invasion, lymph node metastasis and postoperative PGE-MUM levels were independent prognostic factors. In matched pre- and postoperative urine samples obtained from patients who are eligible for adjuvant chemotherapy, an increase in PGE-MUM levels following resection was an independent prognostic factor (hazard ratio 3.017, P = 0.005). Adjuvant chemotherapy improved survival in patients with increased PGE-MUM levels after resection (5-year overall survival, 79.0 vs 50.4%, P = 0.027), whereas survival benefit was not observed in those with decreased PGE-MUM levels (5-year overall survival, 82.1 vs 82.3%, P = 0.442). CONCLUSIONS: Increased preoperative PGE-MUM levels can reflect tumour progression and postoperative PGE-MUM levels are a promising biomarker for survival after complete resection in patients with NSCLC. Perioperative changes in PGE-MUM levels may aid in determining the optimal eligibility for adjuvant chemotherapy.

Examination of the effectiveness of local therapy for oligo-recurrence of EGFR-mutated NSCLC.

BACKGROUND: The effectiveness of local therapy has been reported in patients with oligo-recurrence of non-small cell lung cancer (NSCLC), a metachronous recurrence with a limited number of recurrences, which can be treated with local therapy. Conversely, remarkable progress has been made in systemic therapy for NSCLC with the advent of molecular targeted therapy. In particular, epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are very effective in the treatment of EGFR-mutated NSCLC. There is currently no consensus on treatment for oligo-recurrence of EGFR-mutated NSCLC. METHODS: From 2004 to 2014, 811 patients underwent complete resection for NSCLC at Kitasato University Hospital and, of these, 244 patients developed recurrence. Oligo-recurrence was defined as the presence of two or less recurrent lesions, and 34 patients presented with EGFR-mutated oligo-recurrence. RESULTS: We retrospectively examined and compared the effects of EGFR-TKIs with those of radical local therapy in patients with oligo-recurrent EGFR-mutated NSCLC. The five-year post-recurrence survival (PRS) rates of patients with EGFR-mutated oligo-recurrence who received radical local therapy (n = 23) and those who did not (n = 11) were 59.4 and 45.5%, respectively (p = 0.777). Multivariate analysis revealed no favorable prognostic factors associated with prolonged PRS, and radical local therapies did not improve PRS in patients with oligo-recurrence (p = 0.551). CONCLUSION: Radical local therapy did not affect PRS in patients with oligo-recurrent EGFR-mutated NSCLC. Even in cases of oligo-recurrence, the administration of local therapy in patients with EGFR-mutated NSCLC might be carefully considered.

Computer-based airway stenosis quantification from bronchoscopic images: preliminary results from a feasibility trial.

PURPOSE: Airway Stenosis (AS) is a condition of airway narrowing in the expiration phase. Bronchoscopy is a minimally invasive pulmonary procedure used to diagnose and/or treat AS. The AS quantification in a form of the Stenosis Index (SI), whether subjective or digital, is necessary for the physician to decide on the most appropriate form of treatment. The literature reports that the subjective SI estimation is inaccurate. In this paper, we propose an approach to quantify the SI defining the level of airway narrowing, using depth estimation from a bronchoscopic image. METHODS: In this approach we combined a generative depth estimation technique combined with depth thresholding to provide Computer-based AS quantification. We performed an interim clinical analysis by comparing AS quantification performance of three expert bronchoscopists against the proposed Computer-based method on seven patient datasets. RESULTS: The Mean Absolute Error of the subjective Human-based and the proposed Computer-based SI estimation was [Formula: see text] [%] and [Formula: see text] [%], respectively. The correlation coefficients between the CT measurements were used as the gold standard, and the Human-based and Computer-based SI estimation were [Formula: see text] and 0.46, respectively. CONCLUSIONS: We presented a new computer method to quantify the severity of AS in bronchoscopy using depth estimation and compared the performance of the method against a human-based approach. The obtained results suggest that the proposed Computer-based AS quantification is a feasible tool that has the potential to provide significant assistance to physicians in bronchoscopy.

Predicting reachability to peripheral lesions in transbronchial biopsies using CT-derived geometrical attributes of the bronchial route.

PURPOSE: The bronchoscopist's ability to locate the lesion with the bronchoscope is critical for a transbronchial biopsy. However, much less study has been done on the transbronchial biopsy route. This study aims to determine whether the geometrical attributes of the bronchial route can predict the difficulty of reaching tumors in bronchoscopic intervention. METHODS: This study included patients who underwent bronchoscopic diagnosis of lung tumors using electromagnetic navigation. The biopsy instrument was considered "reached" and recorded as such if the tip of the tracked bronchoscope or extended working channel was in the tumors. Four geometrical indices were defined: Local curvature (LC), plane rotation (PR), radius, and global relative angle. A Mann-Whitney U test and logistic regression analysis were performed to analyze the difference in geometrical indices between the reachable and unreachable groups. Receiver operating characteristic analysis (ROC) was performed to evaluate the geometrical indices to predict reachability. RESULTS: Of the 41 patients enrolled in the study, 16 patients were assigned to the unreachable group and 25 patients to the reachable group. LC, PR, and radius have significantly higher values in unreachable cases than in reachable cases ([Formula: see text], [Formula: see text], [Formula: see text]). The logistic regression analysis showed that LC and PR were significantly associated with reachability ([Formula: see text], [Formula: see text]). The areas under the curve with ROC analysis of the LC and PR index were 0.903 and 0.618. The LC's cut-off value was 578.25. CONCLUSION: We investigated whether the geometrical attributes of the bronchial route to the lesion can predict the difficulty of reaching the lesions in the bronchoscopic biopsy. LC, PR, and radius have significantly higher values in unreachable cases than in reachable cases. LC and PR index can be potentially used to predict the navigational success of the bronchoscope.

Factors associated with lymph node metastasis upstage after resection for patients with micropapillary lung adenocarcinoma.

BACKGROUND: Micropapillary adenocarcinoma has a poor prognostic histological pattern. Additionally, preoperative detection of lymph node metastases by preoperative examination is difficult in some patients with micropapillary adenocarcinoma, and postoperative upstage may occur. However, clinicopathological features of patients with micropapillary adenocarcinoma with nodal upstage have not been established, therefore this study aimed to identify the factors associated with potential lymph node metastases during preoperative examination to ensure effective surgical procedures. METHODS: Between January 2011 and December 2020, 1029 patients received complete resection for primary non-small-cell lung cancer by lobectomy or more extensive resection with systematic lymph node dissection at this institution. One hundred and thirty-one patients diagnosed with adenocarcinoma with micropapillary component were included in this study. The clinicopathological features of patients with nodal upstage whose postoperative N stage was more advanced than the preoperative N stage were examined. RESULTS: Forty patients had nodal upstage after resection. 18 F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) revealed that a maximum standardized uptake value (SUVmax) ≥5 for the primary lesion was significantly associated with postoperative nodal upstage. There were no significant differences in terms of sex, age, smoking history, surgical procedure, and diabetes. Among 38 patients with nodal upstage, 23 patients had no significant preoperative lymphadenopathy and showed no abnormal FDG uptake in the lymph nodes on 18 F-FDG-PET-CT, respectively. CONCLUSIONS: Lymph node metastases were suspected in patients preoperatively diagnosed with micropapillary adenocarcinoma with FDG SUVmax ≥5 for the primary tumor. Therefore, standard surgical resection and careful lymph node dissection should be performed for such patients.

Selection of preoperative stress electrocardiography test for appropriate patients with non-small cell lung cancer.

OBJECTIVE: Lobectomy is an established surgical procedure for treating non-small cell lung cancer; however, it significantly impacts postoperative cardiac function. The stress electrocardiography test is relatively easy to perform and is used to confirm the presence of coronary artery stenotic lesions. However, it has a low pre-test probability and may yield many false positives. We examined the factors that would enable the appropriate selection of patients for stress electrocardiography as a preoperative cardiovascular examination preceding lobectomy for non-small cell lung cancer. METHODS: From June 2016 to July 2018, 240 patients at our institution who underwent stress electrocardiography before lobectomy for primary lung cancer were included in this study. Clinical information was extracted from electronic medical records and evaluated retrospectively. Smoking history, diabetes, hypertension, dyslipidemia, and ischemic heart disease were considered risk factors for coronary artery stenosis. We determined the coronary risk factors that were applicable to each participant and calculated the total number of coronary risk factors as a risk score. RESULTS: Patients with coronary risk factor scores of ≥ 3 were significantly more likely to have abnormal stress electrocardiography results. In addition, these patients also underwent more comprehensive examinations to identify coronary diseases. There were no patients with complications that could be attributed to ischemic heart disease. CONCLUSION: Stress electrocardiography may be more useful before lobectomy in non-small cell lung cancer patients if the patients are appropriately selected, with the test utilized mainly in patients with coronary risk factor scores of ≥ 3.

Subxiphoid dual-port thymectomy for thymoma in a patient with post-aortic left brachiocephalic vein.

Post-aortic left brachiocephalic vein (PALBV) is one of the rare congenital vessel abnormalities associated with congenital heart disease. As only a few reports of surgical treatment for thymic tumor in patients with PALBV are available, this study reports the case of a patient with PALBV who underwent surgical treatment for thymoma. In a 60-year old woman, a nodule in the anterior mediastinum was detected on chest computed tomography (CT) during examination for arrhythmia. Thymoma was suspected, and surgical resection was considered. PALBV was detected on a contrast CT scan before surgery. Video-assisted thoracoscopic surgery was used to perform thymectomy using the subxiphoid dual-port approach. This method provided an appropriate view of the operative field and made it easy to confirm the presence of PALBV and identify the thymic veins branching off from the internal thoracic vein.

[Thoracic Surgery and Perioperative Management for Hemodialysis Patients].

The number of patients receiving hemodialysis has increased, and a proportionate increase of such patients with malignant tumor is expected. Hemodialysis patients are associated with a special condition, which is an obstacle during surgery. Surgery for dialysis patients is associated with high risk due to heart failure, respiratory failure, bleeding tendency, and immunosuppression. Therefore, dialysis patients should undergo sufficient preoperative evaluation and course of dialysis before surgery. In addition, minimally invasive surgery are required to reduce a risk of postoperative complication, and recently video-assisted thoracic surgery is performed. To reduce bleeding, using nafamostat mesilate on hemodialysis is also important management method. Careful infusion is necessary because volume overload causes the most dangerous complications, heart failure and pulmonary edema. Because dialysis patients are easily infected, sufficient care must be taken for wound infection, pneumonia, and empyema. Dialysis patients require careful perioperative management, but standard surgery is possible. However, prognosis for lung cancer with hemodialysis patient is not satisfactory. Future research on postoperative therapy including anticancer drugs is expected.

[Introduction of Minimally Invasive Thoracoscopic Surgery for the Anterior Mediastinum;Subxiphoid Video-assisted Thoracoscopic Thymectomy and Robot-assisted Thymectomy].

In Japan, robot-assisted surgery for malignant lung tumors, benign mediastinal tumors, and malignant mediastinal tumors has been covered by the national health insurance since 2018. Hence, the number of domestic robotic surgical procedures is increasing. Recently, we introduced endoscopic surgery such as video-assisted thoracoscopic surgery (VATS) via a subxiphoidal approach for thymectomy. Here, we compared VATS and robotic surgery via a subxiphoidal approach in terms of clinical factors. During the study period, 5 consecutive patients who underwent robotic thymectomy and 24 patients who underwent VATS were analyzed. Although the operative time was longer in the robotic group, the intraoperative blood loss, postoperative length of stay, and postoperative complications were favorable in the robotic group. The disadvantage of robotic surgery is the necessity for a reduction in operative time including console duration time. However, future developments in the field of robotic engineering will lead to the creation of systems that allow for more advanced surgical techniques. We must chose procedures in consideration of the best method for each patient, and it is necessary to perform robotic surgery based on the expense and therapeutic effect, social environment, and way of life of each patient.

EGFR mutation genotyping and ALK status determination in liquid-based cytology samples of non-small cell lung cancer.

Personalised medicine for primary lung cancers (PLCs) requires molecular analysis of cancer tissue or cells. The primary objective of the present prospective study was to assess the concordance between epidermal growth factor receptor (EGFR) gene mutation detection and echinoderm microtubule-associated protein-like (EML) 4-anaplastic lymphoma kinase protein (ALK) expression using liquid-based cytology (LBC) samples and matched histology samples of PLC patients. A total of 117 patients who underwent surgical resection of non-small cell PLC were enrolled. Cytological specimens scratched from the resected PLC lesion were fixed in CytoRich Red. DNA extracted from LBC samples was examined for EGFR gene mutations. Anaplastic lymphoma kinase arrangement was analysed by immunostaining and fluorescence in situ hybridisation. Our patient cohort comprised 93 cases of adenocarcinoma, 16 squamous cell carcinoma, three adenosquamous carcinoma, two large cell neuroendocrine carcinoma, one pleomorphic carcinoma and two other cases. Sixty-six (58.4%) LBC samples harboured EGFR gene mutations. The overall concordance rate in EGFR gene mutation status, including minor mutations, between histologic and paired LBC specimens (N = 105) was 100%. The overall concordance rate of EGFR gene mutation status, including minor mutations and ALK status according to immunostains between histologic and paired LBC specimens, was 100% (105/105) and 100% (48/48), respectively. Genotyping and protein expression studies can be reliably performed using LBC samples prepared with CytoRich Red. Analysis of such samples may guide individual therapy in PLC patients.

[Challenges Faced by the Palliative Care Team in Treating Breast Cancer Outpatients with Chemotherapy].

In this study, we examined 239 outpatients receiving chemotherapy for breast cancer for a period of 6 months from July 2016 to December 2016. Using a questionnaire, we investigated the patients' symptom score and uneasiness. A symptom score of 2 and over was found in 24.7%(59)of the cases. Twenty-seven of the 59 cases experienced adverse effects of chemotherapy. Peripheral neuropathy was observed in 20 cases, of which only 2 cases improved after providing palliative care. Palliative care was effective against nausea, constipation, malaise, and sleeping disorders. Thirty-two cases(13.4%)had 5 or more painful feeling score. Among these, 10 cases resulted from the adverse effects of treatment, 10 cases from the aggravation of existing cancer, and 6 cases showed anxiety for the illness, family, and future. In 15 of the 32 cases, the pain score improved by providing palliative care, conversation with the nursing staff, reduction in the quantity of drug intake, etc.

Increase in Carbohydrate Antigen 19-9 Levels without Tumor Progression after Polaprezinc Administration that Induced Deep Vein Thrombosis in a Colon Cancer Patient.

Carbohydrate antigen 19-9 (CA 19-9) is a well-known tumor marker of adenocarcinoma (reference range, 37 U/mL). It can also be used, together with computed tomography, to monitor responses and resistance to chemotherapy in cancer patients. False elevation of CA 19-9 levels is often seen in conditions such as biliary tract obstruction and cholangitis. However, whether medication might induce false elevation of CA 19-9 levels has not yet been reported. A 74-year-old man was treated with third-line CPT-11 (irinotecan) plus panitumumab for stage IV cancer of the ascending colon. The patient developed chemotherapy-induced dysgeusia and was treated with polaprezinc. After polaprezinc administration, his CA 19-9 levels gradually increased from 18.9 to 1,699.4 U/mL. He developed deep vein thrombosis (DVT), although it was not associated with progressive disease or metastasis. Upon discontinuation of polaprezinc, CA 19-9 levels gradually decreased. This case demonstrates that polaprezinc may not only induce false elevation of CA 19-9 levels but also cause development of DVT induced by increased CA 19-9 levels, both of which are very rare events.

Relevance of Intraoperative Pleural Lavage Cytology and Histologic Subtype in Lung Adenocarcinoma.

BACKGROUND: The association between pleural lavage cytology (PLC) and histologic subtype remains unknown. In this study, we evaluated the effect of a micropapillary pattern (MPP) in lung adenocarcinomas on results of PLC. METHODS: We retrospectively reviewed 600 consecutive patients with surgically resected pulmonary adenocarcinomas and investigated the relationship between PLC status and clinicopathologic factors, including a histologically identified MPP component. RESULTS: PLC was positive in 25 patients (4.2%). Positive PLC was significantly associated with MPP (p = 0.0001), lymph node metastasis (p = 0.01), and pleural invasion (p < 0.0001) according to multivariate analysis. Furthermore, the presence of MPP reinforced the effect of some established predictive factors, such as large tumor size, lymph node metastasis, pleural invasion, and lymphovascular invasion, on positive PLC. Two factors-MPP and positive PLC-were associated with a higher incidence of occult N2 lymph node metastases. The prognosis of adenocarcinomas in patients with MPP or positive PLC was significantly worse than that of patients without these features. Furthermore, the survival of MPP and positive PLC group (MPP+ PLC+) was significantly worse than that of MPP and negative PLC group (MPP+ PLC-, p = 0.03). CONCLUSIONS: The presence of MPP in lung adenocarcinoma can be an independent predictor of positive PLC. These two factors have complementary and synergistic roles as prognostic factors. Detailed preoperative or intraoperative examination of histologic subtype and PLC findings may provide important information for prediction of tumor progression and decisions regarding the surgical procedure.

Feasible and promising modified trans-subxiphoid thoracoscopic extended thymectomy for patients with myasthenia gravis.

BACKGROUND: We have used a promising, minimally invasive thoracoscopic technique of extended thymectomy for patients with myasthenia gravis (MG). The aim of this study was to report our promising technique, a modified single-port trans-subxiphoid approach (MTXA) and to compare perioperative outcomes and effects on MG between our approach and sternotomy. METHODS: We retrospectively reviewed records of all patients undergoing extended thymectomy for MG and/or thymoma between January 1, 2010 and December 31, 2016. The patients were divided into the MTXA group and Sternotomy group. RESULTS: Of the 50 consecutive patients undergoing extended thymectomy for MG, finally, 13 patients undergoing our MTXA extended thymectomy technique were compared with 20 patients undergoing extended thymectomy via sternotomy. Intraoperative blood loss, postoperative length of stay, and C-reactive protein value on postoperative day 1 were significantly more favorable in the MTXA group than the Sternotomy group (P<0.0001, P=0.0040 and P=0.0073, respectively). Furthermore, no significant differences in the frequency of patients with improvement of their Quantitative Myasthenia Gravis score and/or MG-Activities of Daily Living scale, decrease in the serum level of acetylcholine receptor antibody, and dose reduction of oral prednisone were seen between the two groups. CONCLUSIONS: Our approach to extended thymectomy might be more favorable than sternotomy in patients with MG.

Lung metastases of a uterine tumor resembling ovarian sex-cord tumor: Report of a rare case.

Uterine tumor resembling an ovarian sex-cord tumor (UTROSCT) is a rare type of uterine neoplasm. We present an extremely rare case of lung metastases from a UTROSCT focusing on the cytologic features. A 69-year-old Japanese woman was admitted to our hospital for further examination and treatment for abnormal shadows in the right lung field. She had a history of total hysterectomy for UTROSCT. Moreover, she underwent wedge resection of the right middle lobe for lung metastasis of UTROSCT in 2011. Enhanced chest computed tomography scan revealed a solid nodule 8 mm in diameter in the right upper lobe and a well-demarcated 33-mm mass or nodule in the lower lobe. Under the diagnosis of metastatic tumors from UTROSCT, she underwent wedge resection of the right upper lobe and segmentectomy of the right S8. Cytologically, the stump smear from the resected tumors revealed round to short spindle-shaped neoplastic small cells arranged in sheets with poor cohesion and no cluster formation. The nuclei were irregular in shape, and the chromatin was finely granular, uniform, and increased. Mitotic figures were not observed. Necrosis was absent in the background. Histologically, the final diagnosis was UTROSCT group II. This is an unusual case of metastatic UTROSCT to the lung in which the cytologic features are described.

Postoperative pulmonary function changes according to the resected lobe: a 1-year follow-up study of lobectomized patients.

BACKGROUND: Pulmonary function and patient complaints appear to improve up to 12 months after lobectomy but long-term prospective studies based on clinical data are scarce. Improvement in pulmonary function may depend on the area and extent of the resection and the time from the operation. This prospective study aimed to determine pulmonary function changes according to the resected lobe. METHODS: This prospective study included 59 patients requiring single lobectomy. Total volume and low-attenuation volume (LAV) for each lobe and the entire lungs were calculated based on helical computed tomography images. Vital capacity (VC), forced expiratory volume in one second (FEV1), percent FEV1 (%FEV1), percent lung diffusion capacity for carbon monoxide (%DLco), %DLco divided by the alveolar volume (%DLco/VA), modified Medical Research Council (mMRC) grades, and COPD Assessment Test (CAT) scores were compared at 3, 6, and 12 months after surgery. RESULTS: VC was higher at 12 months than at 3 months after right upper lobectomy (RUL) or right lower lobectomy (RLL). FEV1 and %FEV1 were higher at 12 months than at 6 months after left lower lobectomy (LLL). %DLco was higher at 12 months than at 3 months after RUL or left upper lobectomy (LUL). DLco/VA, mMRC grades, and CAT scores did not change significantly in the period from 3 to 12 months after any lobectomy procedure. Compared to the predicted postoperative values, the observed values of VC for RUL, RLL, and LUL; FEV1 for RLL; %FEV1 for RLL and LUL; %DLco for LUL; and %DLco/VA for all lobectomy procedures were higher at 12 months. CONCLUSIONS: Improvements in pulmonary function and symptoms varied according to the resected lobe. Some of the observed pulmonary function values were higher than the predicted postoperative values. Pulmonary function changes may be related to the location, volume, and extent of emphysematous changes.

Molecular alterations in a new cell line (KU-Lu-MPPt3) established from a human lung adenocarcinoma with a micropapillary pattern.

PURPOSE: Lung adenocarcinomas with a micropapillary pattern (MPP) are characterized by more frequent and pronounced vascular invasion, higher incidence and more advanced lymph node involvement and poorer prognosis than papillary adenocarcinomas without an MPP. Here we established a new lung cancer cell line featuring micropapillary structure. METHODS: A 73-year-old never-smoker Japanese female, presenting with an abnormal chest shadow, was diagnosed with a clinical T2aN0M0 Stage IB lung adenocarcinoma and underwent left upper lobectomy with mediastinal lymph node dissection. Pathological study demonstrated a T2aN2M0 Stage IIIA micropapillary adenocarcinoma. Tumor cells were obtained from freshly resected lung material and used to establish the KU-Lu-MPPt3 cell line. RESULTS: The KU-Lu-MPPt3 cells featured adherent monolayers, adherent tufts, and suspended tufts without adhesion under the same culture conditions. The cells were positive for cytokeratin, epithelial cell-adhesion molecules, E-cadherin, mucin-1, thyroid transcription factor-1, vimentin, and anti-programmed death ligand 1. Xenograft tumors clearly demonstrated micropapillary structures. Sequencing and fragment analysis of the epidermal growth factor receptor in the primary tumor tissue and KU-Lu-MPPt3 cells revealed an in-frame deletion E746-A750 in exon 19. CONCLUSIONS: This cell line represents a new model system for molecular studies of lung adenocarcinoma which may be suitable for investigation of cancer spread and also for development of molecular-targeting and immunotherapies, both in vitro and in vivo.