Usefulness of the Global Leadership Initiative on malnutrition (GLIM) criteria in preoperative nutritional assessment of patients with primary lung cancer.

BACKGROUND AND AIMS: The Global Leadership Initiative on Malnutrition (GLIM) developed a new method for evaluating malnutrition; however, no consensus has been reached regarding the use of these criteria. Therefore, this study aimed to investigate the association between nutritional status assessed using the GLIM criteria and outcomes of lung cancer after surgery. METHODS: Patients with non-small cell lung cancer who underwent lung resection and bioelectrical impedance analysis to estimate muscle mass before surgery were included. Their background, pathological stage, recurrence, and prognosis were investigated. Patients were divided into two groups according to the GLIM criteria: normal nutrition and malnutrition groups. RESULTS: The normal and malnutrition groups comprised 110 and 88 patients, respectively. Malnutrition was significantly associated with poor overall survival after surgery (P = 0.025) but not with disease-free survival. Multivariate analysis showed that malnutrition (hazard ratio [HR]:2.374, P = 0.020), advanced pathological stage of lung cancer (HR: 1.919, P = 0.002), and the presence of postoperative complications (HR: 2.035, P = 0.047) were significantly associated with poor overall survival. CONCLUSION: Malnutrition assessed using the GLIM criteria was associated with the prognosis of patients with postoperative non-small cell lung cancer. Preoperative assessment using the GLIM criteria would allow for effective nutritional and rehabilitative interventions to improve prognosis.

Pulmonary Artery Aneurysm in a Patient with Nontuberculous Mycobacteria Infection.

Nontuberculous mycobacterial (NTM) infection sometimes leads to the development of pulmonary artery aneurysm (PAA), a rare but life-threatening complication. We herein report a 64-year-old woman with a history of NTM infection who presented with severe hemoptysis. Computed tomography revealed a ruptured PAA, which was treated successfully with pulmonary artery embolization. Subsequent right total pneumonectomy was performed to control infection. This case emphasizes the need to consider PAA in patients with NTM infection who present with hemoptysis. Early detection and appropriate management are critical for preventing this fatal complication.

The possibility of mutations of RAS signaling genes and/or TP53 in combination as a negative prognostic impact on pathological stage I non-small cell lung cancer.

BACKGROUND: The recurrence rate of non-small cell lung cancer (NSCLC) is as high as 30%, even in the cancer with pathological stage I disease. Therefore, identifying factors predictive of high-risk pathological recurrence is important. However, few studies have examined the genetic status of these tumors and its relationship to prognosis. MATERIALS AND METHODS: A cohort of 328 cases of primary lung cancer that underwent complete resection at Tokyo Medical and Dental University (TMDU) was screened for 440 cancer-associated genes using panel testing. Further analyses included 92 cases of pathological stage I NSCLC who did not receive adjuvant chemotherapy. Ridge regression was performed to identify association studies mutational status and postoperative recurrence. These data were then validated using clinical and genetic data from 56 patients in The Cancer Genome Atlas (TCGA). RESULTS: Mutations in TP53, RAS signaling genes KRAS and HRAS, and EGFR were recurrently detected. Ridge regression analysis relevant to recurrence, as well as survival analysis, performed using data from the TMDU cohort revealed significantly shorter relapse-free survival (RFS) for patients with RAS signaling or TP53 gene mutations than for those without (log-rank test, p = 0.00090). This statistical trend was also suggested in the TCGA cohort (log-rank test, p = 0.10). CONCLUSION: Mutations in RAS signaling genes and/or TP53 could be useful for the prediction of shorter RFS of patients with stage I NSCLC.

[Minimally Invasive Surgery for Mediastinal Tumor].

We have been performing multiport thoracoscopic surgery as a minimally invasive procedure for mediastinal tumors. The criteria for thoracoscopic surgery are as follow;tumor under 6 cm without invasion of great vessels, chest wall, or lung. We started one port surgery since 2017 and robot-assisted thoracoscopic surgery since 2018. We retrospectively reviewed these three approaches for mediastinal tumor for 12 years. 269 patients underwent surgery for mediastinal tumor, 141 patients by multiport surgery, 21 patients by one port surgery, and 38 patients by robot-assisted thoracoscopic surgery. Of 203 patients with anterior mediastinal tumors, 141 patients underwent thymectomy for thymic tumors (72 patients by multiport surgery, 9 patients by one port surgery, 17 patients by robot-assisted thoracoscopic surgery, and 43 patients by open surgery). There was no difference in tumor size, but the operating time and blood loss were significantly less in one port surgery than in multiport surgery or robot-assisted thoracoscopic surgery. The approaches have become more diverse, with a wider choice of surgical techniques, allowing us to offer more radical minimally invasive surgeries.

High density and proximity of CD8+ T cells to tumor cells are correlated with better response to nivolumab treatment in metastatic pleural mesothelioma.

BACKGROUND: The efficacy of immune checkpoint inhibitors (ICIs) in pleural mesothelioma has recently been established. The response to ICIs can be predicted by quantitative analysis of cells and their spatial distribution in the tumor microenvironment (TME). However, the detailed composition of the TME in pleural mesothelioma has not been reported. We evaluated the association between the TME and response to ICIs in this cancer. METHODS: A retrospective analysis of 22 pleural mesothelioma patients treated with nivolumab in different centers was performed using surgical specimens. Four patients had a partial response to nivolumab (response group) and 18 patients had stable or progressive disease (nonresponse group). The number of CD4, CD8, FoxP3, CK, and PD-L1 positive cells, cell density, and cell-to-cell distance were analyzed by multiplex immunofluorescence. RESULTS: PD-L1 expression did not differ significantly between the response and nonresponse groups. The density of total T cells and of CD8+ T cells was significantly higher in the response than in the nonresponse group. CD8+ T cells were more clustered and located closer to tumor cells, whereas regulatory T cells were located further from tumor cells in the response than in the nonresponse group. CONCLUSIONS: High density and spatial proximity of CD8+ T cells to tumor cells were associated with better response to nivolumab, whereas the proximity of regulatory T cells to tumor cells was associated with worse response, suggesting that the distinct landscape of the TME could be a potential predictor of ICI efficacy in pleural mesothelioma.

Extubation by supraglottic airway after lobectomy prevents cough-associated air leaks and prolonged coughing or sore throat.

OBJECTIVES: Double-lumen endobronchial tubes (DLTs) are essential for differential lung ventilation during pulmonary lobectomy, but they are more rigid, longer, larger in diameter and irritable. Coughing at extubation sometimes causes airway and lung injury, which causes severe air leaks, prolonged cough and sore throat. We examined the prevalence of cough-associated air leaks at extubation and postoperative cough or sore throat after lobectomy and evaluated the efficacy of supraglottic airway (SGA) in preventing these complications. METHODS: Patient characteristics and operative and postoperative factors data were collected from patients who underwent pulmonary lobectomy between January 2013 and March 2022. After propensity score matching, these data were compared between the SGA and DLT groups. RESULTS: A total of 1069 patients with lung cancer (SGA, 641; DLTs, 428) were enrolled and coughing at extubation occurred in 100 (23.4%) patients in the DLT group, 65 (65.0%) showed increased cough-associated air leaks at extubation and 20 (30.8%) showed prolonged air leaks. Coughing at extubation occurred in 6 (0.9%) in the SGA group. In 193 patients from each group after propensity score matching, coughing at extubation and the associated air leak increase were significantly lower in the SGA group. Visual analogue scale of postoperative cough and sore throat on postoperative days 2, 7 and 30 were significantly lower in the SGA group. CONCLUSIONS: SGA is effective and safe for preventing cough-associated air leaks and prolonged postoperative cough or sore throat at extubation following pulmonary lobectomy.

Association between socioeconomic status and net survival after primary lung cancer surgery: a tertiary university hospital retrospective observational study in Japan.

BACKGROUND: Inequalities in opportunities for primary lung cancer surgery due to socioeconomic status exist. We investigated whether socioeconomic inequalities exist in net survival after curative intent surgery at a tertiary university hospital, in Japan. METHODS: Data from the hospital-based cancer registry on primary lung cancer patients who received lung resection between 2010 and 2018 were linked to the surgical dataset. An area deprivation index, calculated from small area statistics and ranked into tertiles based on Japan-wide distribution, was linked with the patient's address as a proxy measure for individual socioeconomic status. We estimated net survival of up to 5 years by deprivation tertiles. Socioeconomic inequalities in cancer survival were analyzed using an excess hazard model. RESULTS: Of the 1039 patient-sample, advanced stage (Stage IIIA+) was more prevalent in the most deprived group (28.1%) than the least deprived group (18.0%). The 5-year net survival rates (95% confidence interval) from the least to the most deprived tertiles were 82.1% (76.2-86.6), 77.6% (70.8-83.0) and 71.4% (62.7-78.4), respectively. The sex- and age-adjusted excess hazard ratio of 5-year death was significantly higher in the most deprived group than the least deprived (excess hazard ratio = 1.64, 95% confidence interval: 1.09-2.47). The hazard ratio reduced toward null after additionally accounting for disease stage, suggesting that the advanced stage may explain the poor prognosis among the deprived group. CONCLUSION: There was socioeconomic inequality in the net survival of patients who received curative intent surgery for primary lung cancer. The lower socioeconomic status group might be less likely to receive early curative surgery.

Extended pleurectomy/decortication and hyperthermic intraoperative intrapleural cisplatin perfusion for malignant pleural mesothelioma.

Objective: To evaluate the efficacy of multimodality treatment including extended pleurectomy/decortication (P/D) and hyperthermic intraoperative chemotherapy (HIOC) with cisplatin for malignant pleural mesothelioma (MPM), we investigated the pharmacokinetics of platinum, adverse events after HIOC, and survival outcome. Methods: Fifty-three patients with pathologically diagnosed MPM (cT1-3N0-1M0, excluding sarcomatoid) underwent an extended P/D and HIOC (cisplatin 80 mg/m2 in saline 2 L, 42°C, 60 minutes) since 2011. The protocol includes postoperative 4 cycles of cisplatin and pemetrexed. Platinum concentrations in the perfusate (before and after) and the serum (1, 2, 4, 8, 24, 48, 72 hours after perfusion) were measured in 10 patients. Mortality and morbidity, especially adverse events of renal function, were investigated, and survival and affecting factors were examined. Results: All patients obtained macroscopic complete resection and pathologic staging revealed as follows: T1/2/3/4: 12/8/23/10, N0/1: 36/17, stage 1A/1B-3A/3B: 12/31/10, respectively. Platinum concentrations in the perfusate indicated that 28% of the dose remained in the pleural cavity, and the maximum concentration in the serum was 0.91 µg/mL. Six patients (11%) showed elevated max-creatinine (>2 mg/dL) postoperatively. Two patients (4%) received renal-replacement therapy, and one was weaned before discharge. There was no 30-day mortality and one in-hospital death (1.9%). Forty-six patients (87%) received multiple cycles of perioperative systemic chemotherapy. Median overall survival (OS) and disease-free survival (DFS) were 52.4 months and 18.7 months. Patents with stage 1A demonstrated a 5-year OS of 67.3% and a median DFS of 67.1 months, and patients with stage 1B-3A demonstrated a 5-year OS of 50.1% and a median DFS of 20.4 months. Univariate analysis showed histological subtype, p-T, p-stage, and multimodality treatment as significant factors affecting OS. Multivariate analysis revealed histology, p-stage, and multimodality as independent. Conclusions: Extended P/D and HIOC with cisplatin for MPM is acceptable with limited acute kidney injury. This multimodality protocol provides promising favorable survival for stage 1A-3A disease.

Reconstruction of the Bifurcation of Right Upper Bronchus Using Miyamoto's Technique for Typical Carcinoid.

A 41-year-old woman presented with productive cough and exertional dyspnea. Bronchoscopy revealed an endobronchial tumor arising from the membrane proximal to the bifurcation of right upper bronchus, and the tumor was a typical carcinoid. The right main bronchus, right upper lobe bronchus, and intermediate bronchus were resected along with the tumor. Intraoperative pathological diagnosis of the bronchial stumps was negative, and bronchial reconstruction was subsequently performed. Two-thirds of the circumference of the right main bronchus and the right intermediate bronchus were anastomosed. The right upper lobe bronchus was anastomosed in an end-to-side fashion. The anastomotic site was covered by the intercostal muscles.

PHOX2B is a Sensitive and Specific Marker for the Histopathological Diagnosis of Pheochromocytoma and Paraganglioma.

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are non-epithelial neuroendocrine neoplasms originating from the adrenal medulla and paraganglion of the sympathetic and parasympathetic nervous system, respectively. PCCs and PGLs show histological similarities with other epithelial neuroendocrine neoplasms and olfactory neuroblastomas (ONBs), and the differential diagnosis of PGLs is particularly difficult. Therefore, we compared the sensitivity of PHOX2A, PHOX2B, and tyrosine hydroxylase (TH) in the histopathological diagnosis of PCCs and PGLs immunohistochemically using the tissue microarrays of 297 neoplasms including PCCs, PGLs, neuroblastomas, ganglioneuromas, epithelial neuroendocrine neoplasms, and ONBs. Using cutoff values of 25%, 5%, and 5% of tumor cells expressing PHOX2A, PHOX2B, and TH, respectively, as positive, 40 of 51 PCCs, 32 of 33 parasympathetic/head and neck PGLs (HNPGLs), 17 of 19 sympathetic/thoracoabdominal PGLs (TAPGLs), and 12 of 152 epithelial neuroendocrine neoplasms, including 123 well-differentiated and 29 poorly differentiated neuroendocrine neoplasms, were PHOX2A-positive. All 51 PCCs, 33 HNPGLs, and 19 TAPGLs were PHOX2B-positive, while all 152 epithelial neuroendocrine neoplasms were PHOX2B-negative. Moreover, 50 of 51 PCCs, 13 of 33 HNPGLs, all TAPGLs, and 12 of 152 epithelial neuroendocrine neoplasms were TH-positive. All ONBs were negative for PHOX2A, PHOX2B, and TH. PHOX2B was the most sensitive and specific diagnostic marker for PCCs and PGLs among PHOX2A, PHOX2B, and TH. PHOX2B can facilitate identification of PCCs and PGLs from epithelial neuroendocrine neoplasms and ONBs, especially in the case of HNPGLs, in which TH is often negative.

Endovascular Treatment for Acute Ischemic Stroke After Video-Assisted Thoracoscopic Pulmonary Lobectomy in Patients With Lung Cancer: A Report of Four Cases and Literature Review.

BACKGROUND: Postoperative cerebral embolic stroke is a serious complication of pulmonary lobectomy, occurring in 1.1% of patients undergoing lobectomy through video-assisted thoracoscopic surgery (VATS). The mechanism of this complication is thought to be embolic stroke caused by thrombus formed due to stagnation in the pulmonary vein stump after VATS lobectomy. There have been few reports demonstrating the utility of endovascular treatment (EVT) for cerebral embolic stroke after VATS lobectomy. CASE DESCRIPTION: In our case series, cerebral embolic stroke occurred after VATS pulmonary lobectomy for lung cancer, including the left upper lobe in three cases and the right lobe in one. The median duration of ischemic stroke after VATS was 4.5 days (interquartile range, 2-9 days). The median time from stroke onset to puncture was 130 min. Successful recanalization was achieved in all cases, and two patients achieved favorable clinical outcomes (modified Rankin scale, 0-2). CONCLUSION: We report a case series of four patients who underwent EVT for acute embolic stroke after VATS lobectomy for lung cancer. EVT is considered a reasonable and feasible therapeutic option for this condition.

Pulmonary Mucormycosis Involving the Left Main Bronchus and the Pulmonary Artery.

Pulmonary mucormycosis is an extremely rare disease. It often occurs in immunocompromised patients, such as patients with diabetes and those on long-term steroid use. The prognosis of the disease is poor despite the administration of antifungal agents and removal of the necrotic tissue. Herein, we present a successfully treated case of pulmonary mucormycosis in a patient with type 2 diabetes who underwent left pneumonectomy because of the involvement of the left main pulmonary artery and the left main bronchus. Irrespective of the infected organ, complete debridement of the infected tissue and treatment with antifungal agents are essential for treating mucormycosis.

Stratification of lung squamous cell carcinoma based on ferroptosis regulators: Potential for new therapeutic strategies involving ferroptosis induction.

OBJECTIVES: Lung squamous cell carcinoma (LSCC) exhibits poor response to treatment compared with other lung cancer subtypes, resulting in worse prognosis. Therefore, new therapeutic strategies are required for advanced LSCC. Ferroptosis is a recently discovered nonapoptotic cell death caused by intracellular lipid peroxidation that can bring about effective cell death in cancer cells resistant to apoptosis. Hence, ferroptosis is a potential therapeutic strategy for refractory cancer. MATERIALS AND METHODS: In this study, we performed clinicopathological and molecular analyses on tumor specimens from 270 patients with squamous cell lung cancer, focusing on the expression of glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1), which are known to be key regulators of ferroptosis, and the accumulation of 4-hydroxynoneral (4-HNE), a lipid peroxidation marker. RESULTS: Immunohistochemistry revealed that patients with low 4-HNE accumulation and low levels of GPX4 or FSP1 had significantly worse prognoses than other patients (P = 0.001). This stratification was an independent prognostic predictor (P = 0.003). A dramatic cell death synergistic effect was observed on LSCC-derived LK-2 and EBC1 cells treated with GPX4 and FSP1 inhibitors. This effect was completely inhibited by treatment with the ferroptosis inhibitor. Notably, this was not the case in LK-2 cells treated with the apoptosis inhibitor, and in these cells, ferroptosis was induced. CONCLUSION: Ferroptosis regulators GPX4 and FSP1 are associated with lung squamous cell cancer cancer's prognosis. We present the clinicopathological and molecular basis of novel therapeutic strategies for refractory LSCC.

Postoperative Delirium in Lung Cancer Anatomical Resection-Analysis of Risk Factors and Prognosis.

BACKGROUND: The incidence of postoperative delirium after anatomical lung resection ranges from 5 to 16%. This study aimed to analyze the risk factors and prognosis of postoperative delirium in anatomical lung resection for lung cancer. METHODS: This study included 1351 patients undergoing anatomical lung resection between April 2010 and October 2020. We analyzed the perioperative risk factors of postoperative delirium. We also compared postoperative complications and survival between the delirium and non-delirium groups. RESULTS: Postoperative delirium was identified in 44 (3.3%) of 1351 patients who underwent anatomical lung resection for lung cancer. Age, peripheral vascular disease, depression, and current smoking status were independent risk factors for postoperative delirium in the multivariate analysis. The percentage of postoperative delirium was 0.6% in never smokers and 6.0% in current smokers. The delirium and non-delirium groups showed significant differences in overall survival (p = 0.0144) and non-disease-specific survival (p = 0.0080). After propensity score matching, the two groups did not significantly differ in overall survival (p = 0.9136), non-disease-specific survival (p = 0.8146), or disease-specific survival (p = 0.6804). CONCLUSIONS: Age, peripheral vascular disease, depression, and current smoking status were considered independent risk factors for postoperative delirium in anatomical lung resection for lung cancer. Smoking cessation for at least four weeks before surgery is recommended for reducing incidence of post-operative delirium.

Successful excision of a giant subcarinal bronchogenic cyst by video-assisted thoracoscopic surgery.

Mediastinal bronchogenic cysts, regarded as congenital foregut abnormalities, are uncommon. These cysts can compress adjacent structures, causing obstructive symptoms and complications. A 57-year-old man was admitted to our hospital with complaints of tachycardia, dyspnea, and chest pain. Enhanced computed tomography revealed a 90 × 90 mm, well-defined subcarinal cystic mass causing significant compression and stenosis of the right main bronchus, right pulmonary artery, and right inferior pulmonary vein. The mass was successfully excised using one window and two-port video-assisted thoracoscopic surgery with partial resection and repair of pulmonary artery, and the postoperative course was good with no recurrence.

Use of carbon nanotube sensor for detecting postoperative abnormal respiratory waveforms.

BACKGROUND: This feasibility study aimed to detect respiratory waveforms from thoracic movements and evaluate if postoperative complications could be predicted using a carbon nanotube sensor. METHODS: Fifty patients who underwent lung resection for lung tumors were enrolled. The lung monitoring system of the carbon nanotube sensor was placed on bilateral chest walls across the 6th-9th ribs to measure chest wall motion. We examined the respiratory waveform in relation to surgical findings, postoperative course, and complications using Hilbert transform and Fast Fourier Transform (FFT). RESULTS: Of 50 patients (37 males, 13 females), 22 were included in the normal lung function group and 28 were included in the low lung function group. The respiratory rate and waveform indicated a regular pattern in the normal lung function group and the respiratory rate could be detected. Conversely, irregular respiratory pattern was detected in 70% of patients in the low lung function group. There was no significant different overall envelope peak value between operated side and non-operated side (0.195±0.05 and 0.18±0.06). In contrast, there was significantly high peak value in the presence of postoperative complications (P<0.05). And there was a significantly higher peak value in air leakage presence than air leakage absence in operated side (P=0.045). CONCLUSIONS: The present study confirmed the feasibility of the sensor. It is promising in visualizing the respiratory state and detecting respiratory changes postoperatively.

Preoperative nutritional status is associated with the prognosis for lung cancer.

BACKGROUND: We investigated whether preoperative nutritional indicators predicted the prognosis for patients with early-stage non-small cell lung cancer. METHODS: Data for stage I or stage IIA non-small cell lung cancer without lymph node metastasis patients who received anatomical lung resection and were followed-up at least five years after surgery (n = 286) were analyzed. We calculated geriatric nutritional risk index, prognostic nutritional index, controlling nutritional status score, and modified Glasgow prognostic score. Multivariate Cox proportional hazard model adjusting for age, BMI, complication, pathological stage, histology of squamous cell carcinoma, T factor, diffusing capacity for carbon monoxide, surgery and smoking status was fitted to evaluate the association between these nutritional indicators and mortality and recurrence within five years. RESULTS: After adjusted for covariates other than type of surgery and diffusing capacity for carbon monoxide, controlling nutritional status of ≥3 was significantly associated with mortality (hazard ratio (HR) = 2.68, 95% confidence interval (CI) = 1.02, 7.01). The association remained marginally significant by adjusting for type of surgery and diffusing capacity for carbon monoxide (HR = 2.44, 95% CI = 0.92, 6.45). controlling nutritional status of ≥3 was significantly associated with recurrence (HR = 2.60; 95% CI: 1.20, 5.61) after adjusting for all covariates. Other nutritional indices did not predict the prognosis in multivariate analysis. CONCLUSION: Preoperative high controlling nutritional status score was marginally and significantly associated with mortality and recurrence of non-small cell lung cancer patients after lung resection.

A rare case of thymoma with entire-tumor calcification.

A 49-year-old woman presented with cough, and chest X-rays showed an abnormal shadow. Chest computed tomography showed an anterior mediastinal 40-mm mass with massive calcification. The patient underwent mediastinal tumor excision performed using video-assisted thoracoscopic surgery. Pathological findings revealed the tumor to be a type B3 thymoma, with massive calcification occupying almost all of the thymoma. Due to high risk of recurrence, we performed completion thymectomy. Pathological findings revealed no remaining thymoma tissue in the residual thymus. Mediastinal tumor with entire calcification could be a candidate for surgical excision.

Intrathoracic omental herniation mimics posterior mediastinal lipomatous tumor.

Intrathoracic omental herniation is an esophageal hiatal hernia that does not involve the stomach and has been previously misdiagnosed as a lipomatous tumor. We report the case of a 72-year-old man who was referred to our hospital for investigation of a chest abnormal shadow. The large mediastinal mass with fat density was not recognized 5 years ago. Although it mimicked a mediastinal lipomatous tumor, we could preoperatively diagnose it as intrathoracic omental herniation. Contrast-enhanced computed tomography was effective in making an accurate diagnosis, showing the mass and vessels passing through the esophageal hiatus from the abdominal cavity. Laparoscopic surgery was performed, and the hiatus was repaired. To diagnose the mediastinal lipidic mass as intrathoracic omental herniation preoperatively can provide less invasive procedure.

Homeobox transcription factor engrailed homeobox 1 is a possible diagnostic marker for adenoid cystic carcinoma and polymorphous adenocarcinoma.

Diagnostic utility of a homeobox transcription factor, engrailed homeobox 1 (En1) in the histopathology of salivary gland neoplasms was studied. The expression of En1 was immunohistochemically examined in 51 cases of adenoid cystic carcinoma (AdCC) and 143 cases of other salivary gland neoplasms. In all 51 AdCCs, En1 was expressed in 30-100% of tumor cells. In eight of nine polymorphous adenocarcinomas (PACs), En1 was expressed in 40-100% of tumor cells. Less than 5% of tumor cells expressed En1 in three of 12 epithelial-myoepithelial carcinomas, one of 17 basal cell adenomas (BCAs), and one of 34 pleomorphic adenomas (PAs). Among 55 other carcinoma cases, 1-30% of tumor cells expressed En1 in three salivary duct carcinomas (SDCs) ex PA. None of the myoepitheliomas and Warthin tumors expressed En1. When the cut-off value of the percentage of En1-expressing cells was set to 25%, all 51 AdCCs, eight of nine PACs and one SDC ex PA were En1-positive and the others were En1-negative. En1 is expressed consistently in AdCCs, frequently in PACs, but rarely in other salivary gland neoplasms. En1 is a possible diagnostic marker for AdCC and PAC in the histopathology of salivary gland neoplasms.