SB Leak Checker^® is a newly developed device to quantitatively measure air leakage after thoracic surgery. SB Leak Checker^® is connected to the conventional drainage system, which enables visual evaluation of air leakage. We conducted a clinical trial to evaluate the effectiveness of SB Leak Checker^®.

SB Leak Checker^® was used in thoracic surgeries performed at our hospital for 12 patients. SB Leak Checker^® values and visual air leakage were observed. Drains were removed as before by the clamp test.

The amount of air leakage measured by SB Leak Checker^® was −76~9 mL/min for no air leakage, −7~84 mL/min for air leakage on coughing, 91~540 mL/min for air leakage on expiration, and 326~1327 mL/min for air leakage on both expiration and inspiration. There was no clear discrepancy between the visual confirmation of air leakage and SB Leak Checker^® value. No adverse events were observed.

SB Leak Checker^® can be used safely and is considered useful for judging whether a drain can be removed.

Congenital hemophilia is a congenital bleeding disease caused by a decrease in the activity of clotting factors. The two common types of hemophilia are: hemophilia A, characterized by decreased factor VIII activity, and hemophilia B, which results from decreased factor IX activity. In 2020, the total number of hemophilia B patients living in Japan was about 1,200; therefore, it is an extremely rare disease.

We report the case of a 17-year-old man diagnosed with an anterior mediastinum tumor of 10 cm in diameter. Imaging studies suggested that the tumor was a mature teratoma. A preoperative blood test revealed a slightly prolonged activated partial thromboplastin time (APTT) of 47 seconds. Although postoperative hemorrhage was observed after a tonsillectomy performed at the age of 12 years, there was no other history of bleeding disorders. The tumor was resected through hemi-clamshell thoracotomy. Bloody drainage fluid and dyspnea were observed on the second postoperative day. Chest CT revealed bloody pleural effusion, atelectasis in the left thoracic cavity, and a hematoma on the posterior of the sternum. A second operation was performed for postoperative bleeding, and bleeding from the posterior surface of the sternum was confirmed. Hemostasis was achieved using an electric scalpel, and no further bleeding was observed after the reoperation. He was diagnosed with congenital hemophilia B because factor IX activity decreased.

Here, we report a case of congenital hemophilia B diagnosed due to postoperative hemorrhage following the removal of a mediastinum teratoma.

A 76-year-old woman underwent radical hysterectomy with bilateral salpingo-oophorectoy and pelvic lymphadenectomy for cervical adenocarcinoma at the age of 58 at her previous hospital. She showed no recurrence during a regular follow-up after surgery at the hospital for 6.5 years. Twelve years later, she exhibited abnormal findings on a chest radiograph during an annual health checkup and was referred to our hospital. Closer examination revealed multiple pulmonary nodules suspected of being malignant, so we performed thoracoscopic biopsy. Histopathological examination initially led to a diagnosis of the tumor as lung adenocarcinoma. However, after immunostaining results: negative for TTF-1; negative for ER and PgR; and partially positive for p16, and comparison with previous pathological specimens, it was finally diagnosed as cervical adenocarcinoma. She is currently undergoing chemotherapy at the Department of Obstetrics and Gynecology of our hospital. It is extremely rare for cervical cancer to recur with pulmonary metastasis more than 10 years after surgery.

The patient was a 74-year-old female diagnosed with primary hyperparathyroidism, due to elevated serum levels of calcium and intact parathyroid hormone. CT and ^99mTc-MIBI SPECT indicated the presence of an ectopic mediastinal parathyroid adenoma, which prompted her referral to our department for its surgical resection. Based on CT, the nodule was buried within the mediastinal fat and would be difficult to identify during surgery. Therefore, radio-guidance with ^99mTc-MIBI and monitoring of intact-PTH were used as intraoperative guides. The operation was performed by hybrid video-assisted thoracic surgery with a 6-cm incision in the 3^rd intercostal space, and we resected the nodule buried in the superior mediastinal fat. The nodule showed high ^99mTc accumulation, and the intact-PTH level decreased after 10 minutes following resection. This led us to conclude that complete resection had been achieved. The final pathological diagnosis was ectopic mediastinal parathyroid adenoma, and there has been no recurrence to date. This outcome suggests that intraoperative guidance using a radioisotope technique along with intact-PTH monitoring may enable more precise excision of mediastinal ectopic parathyroid adenoma, and that accurate identification of the position of the nodule may reduce the rate of recurrence.

A 17-year-old male patient visited his local doctor in January X year with bronchitis, when a chest radiograph revealed an enlarged mediastinal shadow in the right pulmonary hilum, but this was not further investigated as he was asymptomatic. A medical examination the following year revealed a similar finding, and the patient was referred to our hospital. Chest computed tomography (CT) revealed a 10-cm tumor with irregular anterior mediastinum margins, which was suspected of infiltrating the bilateral brachiocephalic veins, superior vena cava, and right atrium. A thoracoscopic tumor needle biopsy was performed in April X+1 for histological diagnosis. The tissue demonstrated a two-cell pattern consisting of small mature lymphocytes and large tumor cells, and immunostaining was strongly positive for c-kit and weakly positive for placental alkaline phosphatase, leading to a diagnosis of seminoma. Chemotherapy (three courses of bleomycin, etoposide, and platinum [BEP]) was administered, causing a significant tumor size reduction. The residual tumor was resected via median sternotomy in August of the same year. CT revealed invasions of the lungs, phrenic nerve, and superior vena cava, and combined resection of the tumor, thymus, and invasive tumor was performed. The pathological diagnosis was reviewed together with a prechemotherapy needle biopsy specimen, which revealed Epstein-Barr virus-Epstein-Barr encoding region positive tumor cells that were positive for epithelial markers, and thymic lymphoepithelial carcinoma (LEC), which is a rare histological type of thymic carcinoma, was diagnosed. The patient is alive and remains relapse-free 3 years after resection. Caution must be exercised in the preoperative needle biopsy diagnosis, especially with small specimen sizes, because seminomas and LEC may show similarities in the site of origin, age at presentation, and pathology. This article reports a review of the literature.

A 68-year-old woman with liver and lung metastases from colon cancer underwent radiofrequency ablation with infusion of intrapleural fluid for liver metastasis. After treatment, transient right chest pain, cough, and bloody sputum were present. Twenty-two days later, whole-body contrast-enhanced computed tomography for evaluation of metastases revealed torsion of the right middle lobe. Since there were no signs of infection or necrosis, video-assisted thoracic surgery was performed 3 days later. As the upper and lower lobes were adherent to the chest wall and diaphragm, respectively, and the interlobar fissure was completely separated, only the right middle lobe without adhesions was considered to have been collapsed by the artificial pleural fluid. Furthermore, the presence of a metastatic lung tumor in the right middle lobe was suspected to have caused the right middle lobe torsion due to buoyancy that inverted the right middle lobe. Although the twisted right middle lobe was adherent to the lower lobe and the visceral pleura was thickened due to inflammation, the right middle lobe was resected safely, and the postoperative course was uneventful. Since it is difficult to predict and prevent lung torsion caused by artificial pleural effusion, it may be possible to preserve the lung with detorsion if the lung torsion is detected by radiological examination early enough.

The blastomatoid variant of pulmonary carcinosarcoma is a rare variant among carcinosarcomas, with only a few cases reported. Here, we describe the case of a 72-year-old man diagnosed with the blastomatoid variant of pulmonary carcinosarcoma. The patient had undergone surgery for hepatocellular carcinoma, and computed tomography (CT) performed during follow-up for postoperative recurrence of hepatocellular carcinoma and postoperative bronchobiliary fistula formation revealed a 28-mm nodule in the lower lobe of the right lung. CT-guided biopsy led to a suspected diagnosis of pleomorphic carcinoma or carcinosarcoma, and surgery was performed for the primary lung cancer. Intraoperative examination revealed that the right lower lobe and diaphragm were tightly adherent to each other due to the bronchobiliary fistula formation, and partial resection of lung was performed. Postoperative histopathology revealed the lung tumor to be a pulmonary blastomatoid carcinosarcoma with a rhabdomyosarcoma component and an epithelial component of H-FLAC (high-grade fetal lung adenocarcinoma). Nine months after pulmonary resection, local recurrence was diagnosed, and the patient received radiotherapy. Thereafter, while the tumor did not increase in size, the general condition of the patient deteriorated rapidly due to progression of the hepatocellular carcinoma, and the patient died 16 months after pulmonary surgery. The prognosis of patients with blastomatoid carcinosarcoma is poor, and there are no established treatments other than complete resection. Since the reported number of cases of pulmonary blastomatoid carcinosarcoma is small, it would be desirable to develop and establish treatment for patients with lung carcinosarcoma.

An 18-year-old woman had been treated for infectious mononucleosis by the Department of Otorhinolaryngology in our hospital. Because a deep cervical abscess formed due to secondary infection, cervical drainage under local anesthesia was performed. Three days after the cervical drainage, enhanced contrast CT showed descending necrotizing mediastinitis. Subsequently, she was referred to us. Emergency mediastinotomy and left intrathoracic drainage with VATS were performed. At the same time, follow-up open drainage of the deep cervical abscess was conducted. After surgery, intrathoracic irrigation by 1 L of saline per day and continuous drainage were performed for ten days. She was discharged on postoperative day 29 with no adverse event. We report the case of a young woman with infectious mononucleosis complicated by descending necrotizing mediastinitis.

Micronodular thymic carcinoma with lymphoid hyperplasia (MNCLH) is a rare disease similar to micronodular thymoma with lymphoid stroma (MNT). MNCLH can be clearly distinguished from MNT by the atypicality of tumor cells, and is tentatively considered a subtype of thymic squamous cell carcinoma in the WHO classification (5th edition). A 48-year-old man was referred to our department for further treatment of a well-defined nodule of 13 mm in diameter in the anterior mediastinum on chest CT. He had no myasthenic symptoms, and serum levels of CEA, SCC, and anti-acetylcholine receptor antibody titers were within normal limits. Thymoma was suspected; thus, a robot-assisted extended thymectomy was performed and the patient was discharged on the fourth day. Pathological examination revealed nodular lesions similar to MNT, but a diagnosis of MNCLH was made based on the findings of strong atypia, CD5, and c-KIT positivity. Since the disease was in the Masaoka I stage, no further treatment was given and the patient has been alive for one year without recurrence.

The patient was a 66-year-old man who visited the hospital with hemoptysis and left anterior chest pain. Chest CT revealed a mass shadow with uneven internal absorption between the upper and lower lobes of the left lung. The left bronchial artery was identified as the feeding vessel of suspected left interlobar hematoma and was embolized, but bloody pleural effusion and progression of left lower lobe atelectasis increased; therefore, medical treatment was determined to be difficult and thoracoscopic hematoma removal was conducted. Solid lesions suggestive of a tumor were unclear, and a large volume of blood clots was observed between the lobes. A portion of the hematoma was submitted for pathological examination, and sarcomatoid carcinoma was diagnosed. There have not been any reports of lung cancer presenting with interlobar hematoma without clear lesions suspected of being a solid tumor. Thus, we report the present case.

A 57-year-old woman was admitted because of bloody septum persisting for 2 weeks. Computed tomography (CT) revealed a 25-mm, well-demarcated, solid nodule in the left lower lobe (S6). She was transferred to our department for surgery and underwent thoracoscopic S6 segmentectomy. Rapid intraoperative cytological diagnosis revealed spindle-shaped cell proliferation. A malignant disease such as a carcinoid, small cell carcinoma, or sarcoma was suspected. In addition, we performed left lower lobectomy and lymph node dissection. Hematoxylin and eosin (HE) staining revealed small, round, neoplastic cells and localized areas of spindle-cell-type tumor cells around the small cells. Therefore, histopathologically undifferentiated carcinoma and high-grade sarcoma needed to be differentiated. Immunohistochemistry indicated that these tumor cells were negative for epithelial markers; therefore, cancer was ruled out. The SYT-SSXI fusion gene was expressed; thus, the definite diagnosis was poorly differentiated type synovial sarcoma. Pneumonia and pulmonary embolism occurred postoperatively, but she recovered well. She was discharged on the 14th postoperative day. Magnetic resonance imaging and positron emission tomography-CT were conducted to detect the primary lesion, but no tumor lesion was found. Therefore, primary pulmonary synovial sarcoma was considered. She has experienced no recurrence for 2 years and 6 months since surgery.

The patient was an 80-year-old man. He was brought to our hospital with a diagnosis of left traumatic hemopneumothorax and fracture of the left 8th-11th ribs due to a fall on the stairs at home. On the day after admission, anemia progressed and chest CT showed increased fluid retention in the left thoracic cavity, so the patient was judged to have persistent intra-thoracic hemorrhage and underwent emergency surgery. Contrary to our expectation, the amount of intra-thoracic hemorrhage was minimal, and no active bleeding was observed at site of rib fracture. Re-examination of the thoracic cavity revealed a tense cystic lesion with a broad-base connection in the anterior mediastinum, and the cyst was resected because of blood retention in it, which was judged to be the cause of the anemia. Pathological diagnosis revealed thymic cyst and microscopic thymoma in a part of the lesion.