A 75-year-old male was found to have an abnormal chest shadow on a radiograph during a medical examination. The patient underwent CT, which revealed a 29-mm nodule lesion in S3 of the right upper lobe. A bronchoscopic biopsy failed to facilitate a definitive diagnosis. In an undiagnosed state, the patient underwent thoracoscopic resection of the right upper lobe combined with resection of the right parietal pleura. Postoperative pathology revealed a diagnosis of pulmonary pleomorphic carcinoma (PPC) pT3 (parietal pleural invasion) N0M0 pStage IIB. The patient did not want to receive any adjuvant therapy and so was followed up. During follow-up, right chest wall relapse appeared 4 months after surgery. The first resection specimen showed high-level expression of PD-L1 (Programmed cell Death Ligand 1), so the patient was treated with Pembrolizumab, and the tumor decreased in size. After that, left pleural effusion appeared, and a diagnosis of relapse of PPC was made by cytology. The patient underwent chemotherapy and the left pleural effusion disappeared, but during the no-treatment follow-up, left pleural effusion appeared again. Thoracoscopic biopsy of the left pleura was performed, and a diagnosis of malignant pleural mesothelioma was made. Currently, the patient is being treated with anticancer drugs for mesothelioma. Pembrolizumab may be effective for PPC with high PD-L1 expression.

A 37-year-old woman visited the emergency department with sudden dyspnea and left thoracic back pain. Chest computed tomography revealed a mass shadow on the left side of the anterior mediastinum and left pleural effusion. Thoracentesis revealed bloody pleural effusion and chest drainage was initiated, but no active bleeding was detected. The mass compressed the left main pulmonary artery, and the potential for invasion could not be eliminated; therefore, hemiclamshell thoracotomy was performed to remove the thymic tumor. Based on the histological findings of the resected specimen, the tumor was diagnosed as type B thymoma. One year postoperatively, pleural dissemination occurred; thus, the lesion was excised. Currently, she is under observation. Reportedly, 4.2% of thymomas exhibit necrosis or hemorrhage. In this case, it is considered that bleeding due to tumor necrosis led to perforation and hemothorax. The long-term prognosis associated with thymoma with perforation is unclear, but pleural dissemination may occur relatively early, as in this case, and so close follow-up is necessary.

The patient was a 71-year-old man. He had noticed a prothoracic bulge for 7 years, was diagnosed with sternal hemangioma by contrast-enhanced MRI, and was followed up. The tumor had grown to the size of a golf ball, so a percutaneous biopsy was performed, but it was discontinued due to excessive bleeding. A needle biopsy was performed again, and although the diagnosis was a hemangioma, the possibility of malignancy could not be ruled out. Surgery was performed to remove the sternal tumor. By embolizing the feeding vessels with a catheter the day before surgery, we were able to reduce the amount of bleeding during the surgery. Although the chest wall defect was reconstructed using mesh, the patient developed a flail chest postoperatively. He required positive pressure ventilation for 5 days but was able to leave the hospital on his own on the 29th postoperative day. One year after surgery, there was no recurrence or abnormal thoracic movement. Sternal tumors are rare, accounting for 0.94% of all bone tumors, and most are malignant. The number of cases of sternal hemangioma that we have encountered is small, with only 10 cases including the present one, and it is considered an extremely rare case.

Extralobar sequestration is often discovered incidentally in asymptomatic patients but rarely in patients with clinical symptoms, owing to stem torsion. This report describes a case of extralobar pulmonary sequestration with torsion that was diagnosed and surgically treated using thoracoscopy. A 12-year-old male was admitted to the Department of Pediatrics after presenting to the Emergency Medicine Department with a complaint of left-sided abdominal pain. On admission, computed tomography (CT) of the thorax and abdomen showed a 3-cm mass in the left thoracic cavity immediately superior to the diaphragm and small pleural effusion in the left paraspinal region. On day 4 of hospitalization, dynamic CT revealed increased left pleural effusion with no contrast enhancement of the mass in the left paraspinal region. The patient was referred to our department because of suspected extralobar pulmonary sequestration with torsion. Thoracoscopic surgery revealed a mass near the descending aorta and a vessel caudal to the descending aorta, which was considered an extralobar sequestration. Although it was difficult to confirm the presence of torsion, the mass was congested and dark red. The surgery was terminated after the vessels were removed and the mass was excised. The histopathological diagnosis was extralobar pulmonary sequestration with hemorrhagic infarction. The patient followed a favorable postoperative course and was discharged from the hospital on postoperative day four.

A 78-year-old female underwent right upper lobe resection and ND2a-2 lymph node dissection for cancer (cT1aN2M0 Stage IIIA). On the first postoperative day, a chest radiograph showed decreased opacity in the right upper lung field, and CT showed consolidation of the middle lobe S⁵, which appeared to be atelectasis, and stenosis of the peripheral bronchi in the middle lobe, but there was no obvious evidence of middle lobe torsion, so the patient was treated conservatively. However, on the third postoperative day, the patient developed a fever in the 38°C range, and CT of the chest showed increased consolidation, so we decided to perform an extra surgery. Intraoperative findings showed that most of the right middle lobe was congested, but there was no evidence of tortuosity of the middle lobe and no problematic veins in the middle lobe. The remaining middle lobe was resected because of the possibility of pulmonary necrosis, and the middle lobe was judged to be nonpreservable. After reoperation, both clinical symptoms and blood tests improved promptly. Although pulmonary torsion is a known postoperative complication that can cause pulmonary congestion, it should be noted that pulmonary congestion can occur without torsion.

Percutaneous needle biopsy for thymic epithelial tumors has been reported to cause bleeding, pneumothorax, and tumor seeding as complications; thus, it is not recommended if the tumor is deemed resectable. Here, we describe a case in which percutaneous needle biopsy was performed, not for the primary tumor, but for pulmonary metastases after thymectomy, resulting in needle tract implantation. The patient was a 74-year-old woman. Computed tomography (CT) showed an enlarging nodule in the lower lobe of the right lung after surgery for type B3 thymoma (WHO classification). It was diagnosed as a recurrent thymoma by CT-guided biopsy and resected. Subsequently, a pleural nodule appeared consistent with the needle biopsy pathway. Clinical suspicion of thymoma recurrence prompted surgical resection, which confirmed the diagnosis. No recurrence was observed 1 year after the surgery. Needle tract implantation of thymic epithelial tumor by percutaneous needle biopsy can occur not only by biopsy for primary tumors but also by biopsy for metastatic sites. Pulmonary nodules appearing in patients with thymic epithelial tumors such as type B3 thymoma or thymic carcinoma, which show a relatively high rate of pulmonary metastasis, should be carefully evaluated for percutaneous needle biopsy, as with primary mediastinal lesions.

Bronchial adenoid cystic carcinoma may require multidisciplinary treatment due to its pathological features. It is difficult to determine preoperatively whether complete resection can be solely achieved by surgery. Furthermore, with the recent increase in the number of elderly patients with lung cancer, it is important to evaluate the outcome of each patient and control the disease by multidisciplinary treatment without compromising the patient's quality of life.

The patient was an 83-year-old man. During a medical checkup, an abnormal chest shadow was noted, and bronchoscopy revealed a polypoid tumor in the bronchus of the right upper lobe. He was diagnosed with class IV adenoid cystic carcinoma by biopsy and referred to our department. At the time of surgery, there was a microscopically suspicious positive bronchial stump that was additionally resected for intraoperative rapid diagnosis, but it was difficult to perform additional proximal bronchial resection because the hilar lymph node was inflammatory and adherent to the main trunk of the right pulmonary artery. Based on the overall judgment, the surgery was terminated with upper lobectomy, the patient was discharged from the hospital, and received a total of 50 Gy of radiotherapy. Postoperative follow-up CT showed no recurrence.

A 69-year-old man presented with a 28-mm solid tumor, showing partial calcification in the anterior mediastinum, detected by chest computed tomography. We considered thymoma with cystic degeneration and performed an operation without preoperative biopsy. Since the tumor was in close proximity to the upper mediastinal vessels, the patient underwent thymothymectomy. The tumor was located in the left upper pole of the thymus. There was marked adhesion between the tumor and vein, but no obvious invasion was detected. Microscopically, the tumor showed multi-lobulated cysts. The cyst wall was comprised of both atypical and normal cells and showed papillary areas protruding into the lumen. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7, focally positive for CK20 and homeobox protein (CDX2), and negative for thyroid transcription factor-1 and CD5. [¹⁸F]-fluorodeoxyglucose positron emission tomography revealed that there was no tumor in any other part of the body, and the patient had no prior medical history of cancer. The tumor was diagnosed as a primary thymic mucinous adenocarcinoma (pT1N0M0 pStage I and Masaoka stage I).

A 25-year-old man with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome presented with an abnormal shadow in the right middle lung area on a chest radiograph. Chest computed tomography images revealed a 30-mm partially solid tumor in segment 4 of the right middle lung. There were no signs of lymph node nor distant metastases. The tumor was suspected to be lung adenocarcinoma based on bronchoscopy. We performed a right middle lobectomy with dissection of the hilar and mediastinal lymph nodes (ND2a-2). We were concerned about lactic acidosis due to mitochondrial abnormalities. Therefore, we used a bicarbonate Ringer solution and normal saline not containing lactate. No signs of convulsions, myopathy, or acute respiratory failure were noted during the perioperative period, and the patient was discharged from the hospital 6 days after surgery. The postoperative diagnosis was primary pulmonary mucinous adenocarcinoma (pT1cN0M0, p-StageIA3). Even in young patients presenting with pulmonary nodules, the differential diagnosis should include lung cancer. In addition, it is necessary to pay close attention to the prevention of complications when performing operative management of MELAS patients.

We report a case of undifferentiated pleomorphic sarcoma of the thoracic wall that was diagnosed preoperatively as local recurrence of primary lung cancer. Based on pathological examination findings, the lesion was an undifferentiated pleomorphic sarcoma.

The patient was an 80-year-old man. Nine years previously, he had undergone thoracoscopic resection of the upper right lung lobe for lung adenocarcinoma. pT3N1M0 stage IIIA cancer was treated with postoperative adjuvant therapy, and the patient had no recurrence. Computed tomography obtained for another disease showed a nodule shadow on the pleural side of the right middle lung field. Local recurrence was suspected as the shadow was located proximal to the previous surgical wound. We initiated surgery following treatment of the intra-atrial thrombus identified preoperatively. Two months into the surgical standby period, the mass enlarged with no distant metastasis, and the patient underwent combined resection of the chest wall and part of the adherent lower right lung lobe. Undifferentiated pleomorphic sarcoma was diagnosed by postoperative pathology. Because of the patient's age and systemic complications, no adjuvant therapy was prescribed. Six months postoperatively, multiple bone metastases appeared, and the patient was transferred to a hospice after palliative irradiation.

Bronchopleural fistula is one of the most serious complications after lung cancer surgery and often requires surgical management. Herein, we present a case of successful conservative management of complete dehiscence of the bronchial stump with localized pyothorax. A 70-year-old otherwise healthy woman underwent thoracoscopic right lower lobectomy with lymph node dissection for lung adenocarcinoma (cT1bN0M0). Pleurodesis was performed for persistent air leak, and she was discharged 11 days after surgery. She developed a bronchopulmonary fistula with complete dehiscence of the bronchial stump 15 days after surgery, but the pyothorax cavity was confined to the mediastinal side due to pleural adhesion. Inflammation reduced after CT-guided drainage and initiation of antibiotic therapy. Although spontaneous closure of the transection did not occur, purification of the lumen was maintained and the drain was removed on the 75th postoperative day. The presence of bronchial epithelium within the organizing lumen of the blind end indicated that the patient was cured. Conservative treatment may obviate the need for open surgery if drainage of the localized pyothorax can control the infection, while also taking into consideration the indications for open surgery.

Needles that penetrate the human body may migrate, causing late complications leading to organ injury. Penetrating chest injury with a needle is rare. Here, we report a case of late-onset post-traumatic pneumothorax caused by a foreign metallic body (a metal wire from a brush) that occasionally penetrated the skin. A 31-year-old man presented to our hospital with chest discomfort. He sometimes felt pain due to a broken piece of wire brush piercing the skin of the anterior chest through his clothing while removing surface paint. Chest computed tomography revealed a right pneumothorax with a foreign body embedded in the first intercostal space of the right thoracic cavity, piercing the chest wall. Traumatic pneumothorax was diagnosed, suggestive of a metallic needle as the cause. Thoracoscopy revealed a metallic needle penetrating the right anterior chest wall. Under chest fluoroscopy guidance, the 2-cm metallic needle was completely removed. Air leakage was not observed on damaged pleural surfaces. Thoracoscopic surgery with chest fluoroscopic assistance was useful for the detection and complete removal of the foreign body. Considering the potential lethality such as greater vessel injury in the anterior mediastinum, early surgical intervention is necessary once a foreign metallic body penetrates the anterior chest wall.

The patient was a 76-year-old man. Six months ago, upon noticing a slight fever and enlarged lymph nodes throughout his body, he visited his regular physician. Thoracoabdominal CT showed a 25-mm nodule in his right lung apex, and an inguinal lymph node biopsy was conducted for diagnosis. He was subsequently diagnosed with mantle cell lymphoma (MCL). Primary lung cancer could not be ruled out for the lung lesion based on its imaging characteristics, so the patient was referred to our department for diagnosis and treatment. Thoracoscopic wedge resection of the right lung was conducted to facilitate biopsy. He was subsequently diagnosed with a tumor composed of coincident adenocarcinoma and MCL. The inguinal lymph node biopsy yielded a diagnosis of MCL, which was considered to be more advanced than the adenocarcinoma. The patient's postoperative course was uneventful. For these reasons, treatment for MCL was promptly started with the involvement of the patient's regular physician. This treatment was effective. Although recurrence was observed after achieving complete remission, the disease stabilized upon restarting treatment. No recurrence of lung cancer has been observed in the 7-year span since his surgery.