[Pulmonary Amyloidosis Observed by Thoracoscopy:Report of a Case].

The case is an 80-year-old woman with Sjögren's syndrome. During the follow-up of multiple pulmonary nodules, an enlarged nodule was observed in the peripheral of the right S3 interlobar region. Fluorodeoxyglucose- positron emission tomography (FDG-PET) showed FDG accumulation only in the S3 nodule, which led to suspicion of primary lung cancer. Because of its difficult location to reach by bronchoscopy, a right lung S3 segmentectomy was performed. Intraoperative findings revealed a hard yellowish- white nodule just below the pleura. Pathological examination showed that the nodule consisted of an acidophilic structureless material, which was positive for Congo red staining and disappeared after permanganate treatment. Based on the above findings, we diagnosed amyloid A( AA)-type amyloidosis. In this case, the nodule was located just below the pleura and we could observe it by thoracoscopy. There have been few reports of thoracoscopic observation of pulmonary amyloidosis, and we report with intraoperative findings.

Effects of tumor-infiltrating CD8+ T cells, PD1/PD-L1 axis, and expression patterns of HLA class I on the prognosis of patients with malignant pleural mesothelioma who underwent extra-pleural pneumonectomy.

Programmed cell death protein-1 (PD1), PD1 ligand 1 (PD-L1), and human leukocyte antigen (HLA) class I molecule play pivotal roles in T cell-induced anti-tumor immunity; however, the clinical impact of these parameters in resected malignant pleural mesothelioma (MPM) cases is unknown. We immunohistochemically evaluated the tumor infiltrated lymphocytes (TILs), PD1/PD-L1 axis, and expression of HLA class I in resected specimens from 58 patients with MPM who underwent extra-pleural pneumonectomy (EPP). Higher infiltration of CD3-TIL, CD8-TIL, and PD1-TIL, loss of HLA class I, and overexpression of PD-L1 by tumor cells (PD-L1 TC) or immune cells (PD-L1 IC) were observed in 34 (58.6%), 27 (46.6%), 41 (70.7%), 45 (77.6%), 29 (50.0%), and 33 (56.4%) of 58 cases, respectively. Interestingly, the CD3-TIL score positively correlated with PD-L1 TC and PD1-TIL scores. HLA class I expression level was inversely correlated with the expression levels of PD-L1 TC and PD-L1 IC. Multivariate analysis showed that age, histology, and node metastasis were independent prognostic factors for 5-year overall survival (OS) and loss of HLA class I coincided with a positive prognosis (p = 0.011). The concomitant lack of infiltrating CD8+ T cells with no loss of HLA class I predicted worse 5-year OS (p = 0.007). Moreover, cluster classifications among multiple immunoparameters showed that categories among CD3/PD-L1 TC/HLA class I (p = 0.043), CD8/PD1/HLA class I (p = 0.032), CD8/PD-L1 TC/HLA class I (p = 0.011), and PD1/PD-L1 TC/HLA class I (p = 0.032) predicted 5-year OS in EPP cases for MPM. These immunoparameters could guide surgical indications for patients with MPM.

An investigation of the internal morphology of asbestos ferruginous bodies: constraining their role in the onset of malignant mesothelioma.

BACKGROUND: Asbestos is a fibrous mineral that was widely used in the past. However, asbestos inhalation is associated with an aggressive type of cancer known as malignant mesothelioma (MM). After inhalation, an iron-rich coat forms around the asbestos fibres, together the coat and fibre are termed an "asbestos ferruginous body" (AFB). AFBs are the main features associated with asbestos-induced MM. Whilst several studies have investigated the external morphology of AFBs, none have characterised the internal morphology. Here, cross-sections of multiple AFBs from two smokers and two non-smokers are compared to investigate the effects of smoking on the onset and growth of AFBs. Morphological and chemical observations of AFBs were undertaken by transmission electron microscopy, energy dispersive x-ray spectroscopy and selected area diffraction. RESULTS: The AFBs of all patients were composed of concentric layers of 2-line or 6-line ferrihydrite, with small spherical features being observed on the outside of the AFBs and within the cross-sections. The spherical components are of a similar size to Fe-rich inclusions found within macrophages from mice injected with asbestos fibres in a previous study. As such, the spherical components composing the AFBs may result from the deposition of Fe-rich inclusions during frustrated phagocytosis. The AFBs were also variable in terms of their Fe, P and Ca abundances, with some layers recording higher Fe concentrations (dense layers), whilst others lower Fe concentrations (porous layers). Furthermore, smokers were found to have smaller and overall denser AFBs than non-smokers. CONCLUSIONS: The AFBs of smokers and non-smokers show differences in their morphology, indicating they grew in lung environments that experienced disparate conditions. Both the asbestos fibres of smokers and non-smokers were likely subjected to frustrated phagocytosis and accreted mucopolysaccharides, resulting in Fe accumulation and AFB formation. However, smokers' AFBs experienced a more uniform Fe-supply within the lung environment compared to non-smokers, likely due to Fe complexation from cigarette smoke, yielding denser, smaller and more Fe-rich AFBs. Moreover, the lack of any non-ferrihydrite Fe phases in the AFBs may indicate that the ferritin shell was intact, and that ROS may not be the main driver for the onset of MM.

Tumor mutation burden as a biomarker for lung cancer patients treated with pemetrexed and cisplatin (the JIPANG-TR).

The JIPANG study is a randomized phase III study of pemetrexed/cisplatin (Pem/Cis) versus vinorelbine/cisplatin (Vnr/Cis) for completely resected stage II-IIIA non-squamous non-small cell lung cancer (Ns-NSCLC). This study did not meet the primary endpoint (recurrence-free survival, RFS) but Pem/Cis had a similar efficacy to Vnr/Cis with a better tolerability. Tumor mutation burden (TMB) is thought to have a predictive value of immune checkpoint inhibitors. However, the relevance of TMB to cytotoxic chemotherapy remains unknown. This exploratory study investigates the relationship between tumor mutation profiles and clinical outcome of Pem/Cis. Formalin-fixed, paraffin-embedded tumor tissues (n = 389) were obtained from the patients. Mutation status of tissue DNA was analyzed by targeted deep sequencing. Epidermal growth factor receptor (EGFR) mutations were detected frequently in Ns-NSCLC (139/374). Patients without any EGFR mutations experienced longer RFS in the Pem/Cis arm versus Vnr/Cis arms. Pem/Cis in patients with high TMB (≥12-16 mut/Mb) tended to have improved survival. In patients with wild-type EGFR, TMB ≥ 12 mut/Mb was significantly associated with improved RFS with Pem/Cis versus Vnr/Cis (not reached vs 52.5 months; hazard ratio (HR) 0.477). It could be proposed that TMB was predictive of RFS benefit with Pem/Cis versus Vnr/Cis in Ns-NSCLC. Further investigation is required to determine whether TMB combined with EGFR mutation status could be used as a predictive biomarker.

[Resection and Reconstruction of the Diaphragm and the Pericardium in Extrapleural Pneumonectomy].

The diaphragm dissection should be started from anterior, because the portion is just under the thoracotomy incision. The diaphragmatic muscle was cut by an electric knife along the line of 1 to 2 cm from the chest wall from anterior and lateral to posterior. The diaphragm including the tendon center is dissected from the peritoneum. The peritoneum should be preserved. If the peritoneum is opened, it should be repaired by sutures. The pericardium is opened at the apex. The pericardium incision is extended from the apex to cranial side. And then, it is cut from the apex to posterior with the diaphragm. And next, the incision of the cranial side edge is extended to posterior. The lower pulmonary vein, upper pulmonary vein, and pulmonary artery are exposed. They are encircled and divided in the pericardium by autosutures. A Goretex sheet with 1 mm thickness is used to reconstruct the diaphragm. Nine sutures were placed in advance for the Goretex, and pulled out from the chest cavity through upper and lower sides of the 10th or 9th rib. The sutures were tied outside the rib cage. For mediastinal side, the Goretex was sutured to the residual diaphragm. A Goretex sheet with 0.1 mm thickness is used to reconstruct the pericardium by interrupted sutures. Because the contralateral lung is overinflated, the reconstruction should not be tight. Slits for the Goretex are made to prevent regional tamponade.

What factors determine the survival of patients with an acute exacerbation of interstitial lung disease after lung cancer resection?

PURPOSES: Acute exacerbation of interstitial pneumonia (AEIP) is a leading cause of death after lung cancer resection in patients with interstitial lung disease. METHODS: We retrospectively analyzed 1763 patients with non-small cell lung cancer with a clinical diagnosis of interstitial lung disease (ILD) who underwent lung cancer resection between 2000 and 2009 at 61 hospitals in Japan. AEIP occurred in 164 of 1763 (9.3%) patients with a mortality rate of 43.9% (72/164). Univariate and multivariate analyses were carried out to identify possible risk factors of fatal AEIP. We then analyzed the 164 patients who developed postoperative AEIP and identified the preoperative and postoperative risk factors. RESULTS: A multivariate regression analysis identified that the sex, percent vital capacity, neoadjuvant radiation, preoperative history of AEIP, preoperative use of steroids, usual interstitial pneumonia pattern on CT, and surgical procedures were independent preoperative risk factors for death due to AEIP. ILD patients with emphysema somehow showed a lower risk of fatal AEIP than those without emphysema in this study. CONCLUSIONS: This study revealed eight risk factors for fatal AEIP.

[Assessment of Fat-free Diet for Postoperative Chylothorax].

BACKGROUND: Chylothorax after lung cancer surgery is relatively rare but must be considered as a complication of thoracic surgery. METHOD: Between January 2012 and June 2017, 818 patients underwent lung cancer surgery at our hospital. Among them, 14 (1.7%) patients with chylothorax were retrospectively reviewed. Three patients were treated with oral intake cessation except water and total parental nutrition( TPN)[TPN group], 11 patients were treated with a fat-free diet( fat-free diet group). RESULTS: The drainage period was similar in both group [group TPN;13 (12~14) days and group fat-free diet;15.7 (6~42) days]. In the TPN group, 3 patients underwent pleurodesis and no patient needed surgical intervention. In the fat-free diet group, 5 patients improved only with diet management. Pleurodesis was necessary in 5 of which 3 underwent surgical intervention. CONCLUSIONS: A fat-free diet is useful in treating chylothorax after lung cancer surgery.

Feasibility of adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent maintenance therapy with S-1 for completely resected non-small-cell lung cancer: results of the Setouchi Lung Cancer Group Study 1001.

BACKGROUND: This multicenter study evaluated the feasibility of novel adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent, long-term maintenance with S-1 in patients with completely resected stage II-IIIA non-small-cell lung cancer (NSCLC). METHODS: Patients received four cycles of S-1 (80 mg/m2/day for 2 weeks, followed by 2 weeks rest) plus carboplatin (area under the curve 5, day 1) followed by S-1 (80 mg/m2/day for 2 weeks, followed by a 1-week rest). Patients unable to continue S-1 plus carboplatin because of severe toxicity converted to single-agent S-1 maintenance. The duration of adjuvant chemotherapy was 10 months in both situations. The primary endpoint was feasibility, defined as the proportion of patients who completed four cycles of S-1 plus carboplatin and single-agent S-1 maintenance for 10 months. The treatment completion rate was determined; treatment was considered feasible if the lower 90% confidence interval (CI) was ≥50%. RESULTS: Eighty-nine patients were enrolled, of whom 87 were eligible and assessable. Seventy-eight patients (89.7%) completed four cycles of S-1 plus carboplatin and 55 (63.2%) completed the following S-1 maintenance therapy for a total of 10 months. The treatment completion rate was 63.2% (90% CI, 54.4-71.2%), indicating feasibility. There were no treatment-related deaths. Grade 3/4 toxicities included neutropenia (13.8%), thrombocytopenia (11.5%), and anorexia (4.6%). The 2-year relapse-free survival rate was 59.8%. CONCLUSIONS: We concluded that adjuvant chemotherapy with S-1 plus carboplatin followed by single-agent maintenance therapy with S-1 is feasible and tolerable in patients with completely resected NSCLC. CLINICAL REGISTRATION NUMBER: UMIN000005041.

[Air Bubble in the Left Ventricle due to Computed Tomography Guided Lung Needle Biopsy].

Computed tomography (CT) guided lung biopsy is a useful examination in diagnosing pulmonary diseases, but the complications such as pneumothorax or pulmonary hemorrhage can not be ignored. Among them, air embolization is a severe complication, although it is infrequently encountered. Forty two-year-old man admitted to our department for the examination of left lung tumor. CT guided lung biopsy was performed. After examination, the patient showed disturbance in cardiac function, which recovered in several minutes. Chest CT revealed air bubble in the left ventricle. After 2-hours head down position followed by bed rest, air bubble is confirmed to be dissappeared by CT.

Double polytetrafluoroethylene patch repair for diaphragmatic defect caused by diaphragmatic rupture following diaphragmatic resection with endostapler.

A 41-year-old man developed phrenic nerve palsy after the resection of anterior mediastinal tumor, who underwent diaphragmatic resection with an endostapler. After the surgery, the surgical stump ruptured, resulting in a large diaphragmatic defect with the liver prolapsing into the thoracic cavity. Then, the diaphragmatic defect was closed with a polytetrafluoroethylene (PTFE) patch. The diaphragm was reconstructed using a second PTFE patch overlaying the diaphragmatic defect that had been closed by the first PTFE patch, because solely patching the diaphragmatic defect had a risk of recurrence of diaphragmatic elevation due to remaining original diaphragm and the presence of phrenic nerve palsy. The second PTFE patch was fixed to the lower ribs by non-absorbable suture. The postoperative course was favorable. After 3 months, his symptoms and pulmonary function improved. We underwent double PTFE patch repair in a patient with both huge diaphragmatic defect and phrenic nerve palsy.

Microscopic thymoma with a thymic cyst that enlarged over a 2-year period.

An 81-year-old woman was referred to our hospital because of right lung cancer. She underwent right upper lobectomy. Pathological examination revealed stage 1A adenocarcinoma. Four months postoperatively, chest computed tomography showed a small nodule with a diameter of 6 mm at the anterior mediastinum. After 2 years, the nodule had increased to 13 mm. To confirm the diagnosis and treat the mediastinal tumor, we resected the tumor and surrounding thymic tissue by a left robotic thoracic approach, considering the adhesion in the right thoracic cavity after right pulmonary resection. The operating time was 43 min. The patient had a favorable postoperative course and was discharged 3 days after surgery. Pathological examination revealed microscopic thymoma with a diameter of 400 µm very close to a thymic cyst. Microscopic thymoma can occur around a thymic cyst without myasthenia gravis, and the thymic tissue around the anterior mediastinal cyst should be resected.

Combined resection of lung cancer and thoracic aortic wall with simultaneous thoracic aortic endografting: a case report.

BACKGROUND: Combined resection of lung cancer and the thoracic aortic wall with thoracic aortic endografting has been reported. However, whether the resection and endografting should be performed simultaneously or in two steps remains controversial. CASE PRESENTATION: A 68-year-old man was referred to our hospital because of left chest pain. Chest contrast-enhanced computed tomography revealed a huge tumor of the left lower lung lobe, and invasion to the aortic wall was suspected. Bronchoscopic examination was performed, revealing squamous cell carcinoma with a programmed death ligand 1 expression level of 90%. The clinical stage was T4N0M0 stage 3A. After neoadjuvant chemotherapy and radiotherapy, we performed one-stage surgery with the patient in the right lateral decubitus position and the left inguinal region exposed for femoral vessel isolation. Posterolateral thoracotomy was performed with making a latissimus dorsi muscle flap. The pulmonary artery, vein, and left lower bronchus were cut with a stapler. After hilar isolation, we evaluated the involvement of the descending aorta and marked the area of the involved aortic wall by a surgical clip. Using the left femoral artery approach, a GORE TAG conformable thoracic stent graft was delivered to the descending aorta. After thoracic aortic endografting, the involved aortic wall was resected and the left lower lobe of the lung and resected aortic wall were resected en bloc. The adventitial defect was covered by the latissimus dorsi muscle flap. The operating time was 474 min, and the blood loss volume was 330 mL. The postoperative pathological diagnosis was adenocarcinoma with an epidermal growth factor receptor mutation of exon 19 deletion. The residual viable tumor was 7 mm in diameter and close to the resected aortic wall. The patient's postoperative course was uneventful. Five days after surgery, chest contrast-enhanced computed tomography revealed no endoleak or stent migration. Three months after surgery, he was alive with neither recurrence nor stent graft-related complications. CONCLUSIONS: One-stage surgery involving combined resection of lung cancer and the thoracic aortic wall with simultaneous thoracic aortic endografting in the right lateral decubitus position with the left inguinal region exposed is safe and acceptable.

Prognostic impact of lymphovascular invasion compared with that of visceral pleural invasion in patients with pN0 non-small-cell lung cancer and a tumor diameter of 2 cm or smaller.

BACKGROUND: Both visceral pleural invasion (VPI) and lymphovascular invasion (LVI) have been shown to be adverse prognostic factors for early-stage non-small-cell lung cancer (NSCLC). Positive VPI upstages the T category of tumors ≤ 2 cm (T1a) to T2a, whereas LVI is not adapted as a descriptor for the Tumor, Node, Metastasis classification system. This study was conducted to evaluate the prognostic impacts of VPI and LVI in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm. METHODS: We reviewed records of a total of 142 patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm, who underwent lobectomy with hilar and mediastinal lymph node dissection between January 2001 and December 2009. We conducted univariate and multivariate analyses to evaluate the impact of VPI, LVI, and other clinicopathologic factors on survival. RESULTS: Visceral pleural invasion and LVI were diagnosed as positive in 18 (12.7%) and 22 (15.5%) patients, respectively. Male sex, squamous cell carcinoma, positive VPI, and positive LVI were risk factors for overall survival. Squamous cell carcinoma, positive VPI, and positive LVI were risk factors for relapse-free survival. In multivariate analysis, squamous cell carcinoma and positive LVI were independent risk factors for overall survival, and positive LVI was an independent risk factor for relapse-free survival. CONCLUSIONS: Positive LVI was more important than VPI as a prognostic factor in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm. Adjuvant chemotherapy should be considered for such patients, to improve the treatment outcomes.

[Pulmonary abscess caused by fish bone].

We describe an extremely rare case of pulmonary abscess caused by fish bone which stabbed the lung from transesophageal route. A 60-year-old woman referred to our hospital complaining of fever. Three days before, she had swallowing pain while eating the bony parts of a fish. An examination on admission showed that C-reactive protein (CRP) is 9.70 mg/dl. Chest computed tomography (CT)revealed, 4 cm mass shadow in the right upper lobe and fish bone material in the mass shadow. Esophagography showed no abnormal findings. Right upper lobectomy was performed under the diagnosis of pulmonary abscess by fish bone. Post operative course was uneventful. The cause was suspected of migration of a fish bone into the right upper lobe via mediasinum and thoracic cavity from esophagus.

Successful use of left ventricular support device (Impella 5.0) and extracorporeal membrane oxygenation (ECMO) for postoperative cardiac arrest after lung cancer surgery: a case report.

Postoperative hemodynamic support with an Impella 5.0 was effective in a man who underwent lung lobectomy for lung cancer and cardiogenic shock. A 75-year-old man presented to hospital with an abnormal chest shadow on radiography. After thorough examination, the patient was diagnosed with lung cancer, and left lower lobectomy was performed. On the 2nd postoperative day, the patient experienced cardiac arrest because of a sudden drop in saturation of percutaneous oxygen. After a third defibrillation, his heartbeat resumed, and he was intubated and placed on a ventilator. Coronary angiography revealed acute coronary syndrome and the patient fell into a state of shock, which required venoarterial extracorporeal membrane oxygenation (VA-ECMO) support. Nevertheless, the circulatory dynamics are unstable, and Impella 5.0 was introduced. VA-ECMO and the Impella 5.0 were discontinued on the 6th and 8th postoperative days, respectively. The patient was eventually transferred to a nearby facility for further rehabilitation 109 days later.

Right upper lobectomy for lung cancer with a displaced right bronchus: Two case reports.

Case 1 describe a 73-year-old man with an abnormal opacity in the upper lobe of the right lung on chest computed tomography (CT), which was done during the postoperative follow-up for bile duct cancer. The chest CT scan showed a ground glass nodule (GGN) measuring 1.0 cm and another one measuring 0.6 cm of the right lung. Case 2 involved a 79-year-old woman with an abnormal opacity in the upper lobe of the right lung on a chest CT that was obtained after she fell down the stairs. The CT scan showed a solid mass measuring 3.0 cm in the right upper lung. Both the patients underwent bronchoscopy before surgery and showed bronchial branching abnormalities. The surgical procedures could be performed accurately since sufficient information had been acquired pre-operatively and they diagnosed lung cancer. Both the patients were able to undergo radical surgery for lung cancer and are currently doing well with no postoperative complications or recurrence of lung cancer.

Identification of cancer stem cell markers in human malignant mesothelioma cells.

Malignant mesothelioma (MM) is an aggressive and therapy-resistant neoplasm arising from the pleural mesothelial cells and usually associated with long-term asbestos exposure. Recent studies suggest that tumors contain cancer stem cells (CSCs) and their stem cell characteristics are thought to confer therapy-resistance. However, whether MM cell has any stem cell characteristics is not known. To understand the molecular basis of MM, we first performed serial transplantation of surgical samples into NOD/SCID mice and established new cell lines. Next, we performed marker analysis of the MM cell lines and found that many of them contain SP cells and expressed several putative CSC markers such as CD9, CD24, and CD26. Interestingly, expression of CD26 closely correlated with that of CD24 in some cases. Sorting and culture assay revealed that SP and CD24(+) cells proliferated by asymmetric cell division-like manner. In addition, CD9(+) and CD24(+) cells have higher potential to generate spheroid colony than negative cells in the stem cell medium. Moreover, these marker-positive cells have clear tendency to generate larger tumors in mouse transplantation assay. Taken together, our data suggest that SP, CD9, CD24, and CD26 are CSC markers of MM and could be used as novel therapeutic targets.

[Clinical assessment of granulocyte colony-stimulating factor producing lung cancer].

OBJECTIVE: The aim of this study was to reveal the clinicopathological feature of granulocyte colony-stimulating factor (G-CSF) producing lung cancer. METHOD: Nine cases of G-CSF producing lung cancer from July 2003 to July 2008 were retrospectively evaluated. RESULTS: All cases were male, 8 cases were poorly differentiated carcinoma. Average of leucocyte and serum G-CSF were 23,378/microl and 128.6 pg/ml respectively. Five cases had febrile symptom, average of serum C-reactive protein (CRP) was 13.37 mg/dl. Immunohistological examination showed positive staining for G-CSF in 6 cases. Serum interleukin-6 (IL-6) level was elevated in 3 cases. Clinical stages were IB in 2, IIB in 2, IIIA in 3 and IIIB in 2 patients. Chemotherapy was performed for patients with stage IIIB. Operation was performed for the other cases. Five cases were died within 12 months, whereas 4 cases are surviving for 6 to 16 months. CONCLUSION: Generally, the prognosis of G-CSF producing lung cancer seems to be poor, but in our institute there were 2 cases who lived over 1 year without disease. It is important to establish more effective adjuvant therapy for G-CSF producing tumor.

Malignant pleural mesothelioma with heterologous elements.

AIMS: Malignant pleural mesothelioma with heterologous elements (such as osseous, cartilaginous or rhabdomyoblastic differentiation) is very rare. We tried to differentiate such mesothelioma cases from extraskeletal pleural osteosarcoma, which is very challenging. METHODS: We compared 10 malignant pleural mesotheliomas (three biphasic and seven sarcomatoid types) with two pleural osteosarcomas using clinicopathological and immunohistochemical methods, and also fluorescence in situ hybridisation (FISH) to examine for homozygous deletion of p16. RESULTS: The median age was 72 years for mesotheliomas, and 69 years for osteosarcoma. For mesothelioma, eight cases were male and two were female. Growth was diffuse in all mesothelioma cases except case 10, where it was localised, as it was for the two osteosarcomas. Among mesothelioma cases, 80% displayed osteosarcomatous and 60% chondromatous elements, while 10% exhibited rhabdomyoblastic ones. Immunohistochemical labelling for calretinin and AE1/AE3 was present in 8/10 and 7/10 mesotheliomas, respectively, but in only one osteosarcoma. Loss of methylthioadenosine phosphorylase was seen in 5/7 mesotheliomas. FISH analysis revealed homozygous deletion of p16 in 5/8 mesothelioma and 2/2 osteosarcoma. Median survival was 6.5 months after biopsy or surgical operation in mesothelioma, and 12 months after operation in osteosarcoma. CONCLUSIONS: Although median survival was longer for osteosarcoma than for malignant mesothelioma, we could not differentiate mesothelioma from pleural osteosarcoma on the combined basis of clinicopathological and immunohistochemical data, and FISH analysis. However, diffuse growth was more frequent in mesothelioma than in osteosarcoma.

[Pericardial cyst that involved thoracic duct].

A 79-year-old man was admitted to our hospital because of swallowing disturbance. Chest X-ray and computed tomography (CT) scan revealed 7 x 6 cm cystic shadow in posterior mediastinum. We diagnosed that swallowing disturbance caused by pericardial cyst. Cysticotmy was performed. Three days after operation, chylothorax occurred. Conservative therapy was not effective, we performed re-operation 28 days later from the 1st operation. There was aperture of thoracic duct inside of cyst, and thoracic duct was ligated. After the 2nd operation, chylothorax was cured.