Background: This study aimed to compare the surgical results of thymomectomy with those of thymothymectomy in nonmyasthenic patients with Masaoka stage I and II thymomas.

Methods: We investigated 65 patients who had no clinical evidence of myasthenia gravis and underwent thoracoscopic resection for stage I and II thymomas between 2005 and 2018.

Results: The operative time was shorter in the thymomectomy group than in the thymectomy group. The amount of bleeding, length of postoperative hospital stay, and morbidity rates were equivalent between the two groups. There was neither recurrence of thymoma nor postoperative development of myasthenia gravis in either group over the median follow-up of 4 years. The distance between the tumor and left brachiocephalic vein was significantly longer in the thymomectomy group.

Conclusions: The result of thoracoscopic thymomectomy was equivalent to that of thymectomy for stage I and II thymomas. Thoracoscopic thymomectomy may be a choice of treatment when the distance of the tumor to left brachiocephalic vein is more than 20 mm.

Background: Pulmonary pleomorphic carcinoma is a rare tumor associated with a poor prognosis. In this study, we assessed the clinical features of patients with surgically resected pleomorphic carcinoma.

Methods: Twenty-eight patients who underwent surgical resection of pulmonary pleomorphic carcinoma between August 2002 and January 2020 were retrospectively analyzed.

Results: The patient population consisted of 25 men and 3 women between the ages of 46 and 87 years (median, 73 years), of whom 25 (89%) were smokers. The mean diameter of the tumor was 44.6 mm (range, 17-92 mm). With regard to lymph node metastasis, 22 cases were pN0, 5 were pN1, and one was pN2. The median survival time was 32.0 months, the 5-year overall survival (OS) rate was 39.5%, and the 3-year relapse-free survival (RFS) rate was 31% in all patients. An immunohistochemical study of the resected tumor revealed expression of programmed death-ligand 1 (PD-L1) in 6 patients. An immune checkpoint inhibitor (ICI) was used in all 6 of these cases, and was successful in 5.

Conclusion: In this study, the prognosis of patients with pleomorphic carcinoma was poor. No specific prognostic factors were found, but ICI treatment is likely to be effective.

Mucormycosis tends to develop in patients with underlying diseases, as an opportunistic disease. Pulmonary mucormycosis rarely shows bone invasion. Herein, we report a case of pulmonary mucormycosis with chest wall invasion that was successfully treated with lung resection and chest wall removal. A 66-year-old female, who had received chemotherapy for acute myeloid leukemia, complained of chest pain. Chest CT showed left upper lobe pneumonia. The diagnosis could not be confirmed even with various inspections including several cultures. As she was a compromised host, invasive pulmonary aspergilloma was suspected, and she was treated with amphotericin B. However, pneumonia progressed to a 90 mm lung abscess and showed bone invasion. Hence, surgical treatment was considered, and we performed left lung upper segmentectomy and chest wall resection with posterior parts of 3^rd-5^th ribs. The histopathological diagnosis of pulmonary mucormycosis was confirmed. The postoperative course was good, and chemotherapy for acute myeloid leukemia was restarted with no recurrence of pulmonary mucormycosis. Complete resection was achieved with extensive chest wall resection. In addition, early restart of chemotherapy was possible due to a preserved respiratory function and less extensive lung resection by segmentectomy.

An 84-year-old male, who underwent thoracoscopic biopsy of the pleura due to pleural effusion and pleural callosity of the right chest and was consequently diagnosed with pleural plaques, developed pleural empyema after the biopsy. The empyema was refractory to thoracoscopic pleural curettage; therefore, open window thoracostomy was performed. After a total of 5 curettements of the calcified pleural plaques and the management of comorbidities such as diabetes and congestive heart failure, the thoracostomy was successfully closed with a pedicled omental flap transposition while a large cavity remained unfilled. The principle of a successful thoracostomy closure is considered to be achieving asepsis in the thoracic cavity and subsequent filling of the cavity by completely closing the dead space. We will discuss the possible reasons why the empyema was cured without the complete obliteration of the dead space in the present case.

Pyogenic arthritis of the sternoclavicular joint is rare. Although various case reports of this condition during the period from the acute phase through the subacute phase have been reported, there are no reports about the chronic phase. Here, we describe such a case. A 49-year-old man had recurrent fever and swelling in the right chest wall lasting for 4 months. He was previously diagnosed with arthritis by clinical presentation and physical findings and prescribed an oral corticosteroid, but showed no symptom improvement.

Hence, he was admitted to our hospital. Computed tomography showed erosion of the medial end of the right clavicle and manubrium, along with abscess formation around the sternoclavicular joint, which extended into the pectoralis major muscle, based on which we diagnosed him with pyogenic arthritis of the sternoclavicular joint. We performed thoracic drainage and debridement, together with resection of the sternoclavicular joint and partial excision of the manubrium, clavicle, right first rib, and pectoralis major muscle. The patient was discharged on the 18th postoperative day. He is currently doing well without relapse of infection at 12 months postoperatively.

A 78-year-old woman was diagnosed with an abnormal shadow on a chest radiograph taken in December 2012. The patient underwent resection of the left upper lobe for lung cancer and nontuberculous mycobacteriosis, and received postoperative chemotherapy for nontuberculous mycobacteriosis. She developed pneumothorax 33 months postoperatively. Six months after an operation for pneumothorax, she presented with a bronchopleural fistula. We performed fenestration of the bronchopleural fistula and empyema, and histopathological evaluation of specimens obtained from the empyema cavity revealed Aspergillus infection. We ensured that the empyema cavity was clean for 6 months. We transposed a free omental flap to the empyema cavity, sealed the fistula with the flap, and performed thoracoplasty. The patient's postoperative clinical course was uneventful, without recurrent empyema during a follow-up period of 55 months. We consider transposition of a free omental flap and thoracoplasty as one of the effective therapeutic strategies for the management of bronchopleural fistulas and chronic empyema.

A 67-year-old man had undergone subtotal gastrectomy and low anterior resection because of gastric and rectal cancer. A solid nodule was detected in the right upper lobe on CT after the surgery and he was referred to our hospital. Although transbronchial lung biopsies were performed, the histological diagnosis could not be confirmed. Evaluation of the intraoperative frozen sections revealed low-grade primary lung adenocarcinoma, and so right upper lobectomy and lymph node dissection were performed. The pathological diagnosis was pulmonary adenocarcinoma with choriocarcinomatous features. The patient remains alive with no recurrence without adjuvant chemotherapy.

A tracheal tumor can be resected through a median sternotamy or a right thoracotomy. Tracheal cancer located in the lower part of the trachea was resected through a median sternotamy, which provided good exposure. A 43-year-old woman was referred to our hospital due to wheezing. Chest computed tomography (CT) revealed a 16-mm nodular mass originating from the left side of the trachea with a 20-mm nodular mass connected outside the trachea near the aortic arch. Bronchofiberscopy showed a tracheal tumor, which occluded 80% of the tracheal lumen. Biopsy showed adenoid cystic carcinoma with cribriform features, which was reported to be more invasive. She underwent circumferential resection and end-to-end anastomosis of the trachea through a median sternotomy. Pathological diagnosis during surgery was not performed. Because of the positive margin, she received adjuvant radiation therapy 2 months after surgery, and has survived for 2 years without any signs of recurrence.

A 67-year-old man was scheduled to undergo catheter ablation for paroxysmal supraventricular tachycardia (PSVT), but was referred to our department because a mediastinal cyst was found. The cyst was 44 mm in size and under the tracheal bifurcation. It was compressing the esophagus, left upper pulmonary vein, and left atrium. Operative findings revealed the cyst to be benign without a solid component, but close adhesion was observed to the esophagus, superior pulmonary vein, and left atrium. The adhesion was not peeled off, the cyst wall was partially removed, and the mucosa was cauterized. Histologically, columnar epithelium and cartilage were observed, and it was considered to be a bronchial cyst. The arrhythmia disappeared postoperatively. Bronchial cysts with arrhythmia are rare, and only 11 cases have been reported globally.

The Japanese national health insurance program has covered robot-assisted lung resection since April 2018. The number of these resections has increased markedly, but there are few reports of complications. We report the case of a patient who developed postoperative bleeding related to robot-assisted lung resection. The patient was a 54-year-old male. We performed robot-assisted right-lower lobectomy and lobe-specific lymph-node dissection. The operation was completed as planned. However, hemorrhagic shock with massive bleeding occurred 6 hours after the surgery. We performed an emergent re-operation and found a massive hematoma. Bleeding from the artery in front of the vertebral body was observed and was stopped by suturing. We considered that this hemorrhage was caused by contact with the robot instrument-vertebral body outside of the video monitor display area. CO₂ insufflation caused exclusion of the posterior mediastinum, and the angle of the robot forceps became steep. In the near field of view, we did not visually detect instrument-vertebral body contact. We also could not recognize vertebral compression by the robot instrument because of a lack of tactile feedback, and the CO₂ insufflation had suppressed the bleeding temporarily. This case illustrates the importance of understanding the differences in characteristics between conventional surgery and robot-assisted surgery and of anticipating potential problems.

Micronodular thymoma with lymphoid stroma (MNTLS) is rare, accounting for 1.4% of the total cases of thymoma. We report two surgical cases of MNTLS. Case 1: The patient was a 60-year-old woman who had a 17-mm nodule in the anterior mediastinum that was revealed by chest computed tomography during a medical checkup. We performed video-assisted thoracoscopic thymectomy. Case 2: The patient was a 70-year-old woman who had an 18-mm nodule in the anterior mediastinum that was also revealed by chest computed tomography during a medical checkup. We performed video-assisted thoracoscopic thymectomy. Both resected tumors were well-defined and homogenously white in color. Histopathological findings of the tumors revealed separation by an abundant lymphoid stroma with a field of tumor cells. Immunohistochemical staining showed that the tumors were positive for pankeratin in the field of tumor cells. The histopathological diagnosis was MNTLS. The long-term outcomes after the resection of MNTLS were good in previous reports. Case 1 has survived without recurrence for four years, and Case 2 has survived without recurrence for one year and six months.

Broncho-pulmonary artery fistula is often caused by pulmonary artery inflammation due to bronchial anastomotic site leakage. Here, we report a case of broncho-pulmonary artery fistula caused by contact with a bronchial stent stud, which was placed for anastomotic site stenosis after sleeve lobectomy. A 74-year-old man underwent right upper sleeve lobectomy and mediastinal lymph node dissection for squamous cell carcinoma that had invaded his right 2^nd carina. Six months later, he began to develop anastomotic site stenosis. We performed balloon dilatation 10 months after lobectomy. Since stenosis recurred after this procedure, we placed a bronchial silicone stent at the anastomotic site 11 months after the lobectomy. Eight days after placing the stent, he suffered massive hemoptysis. Because chest-enhanced computed tomography showed that a distal stent stud had pushed through the bronchial wall and was next to the right pulmonary artery, we diagnosed the patient with a broncho-pulmonary artery fistula. After intubating with a double-lumen endotracheal tube, we performed temporary unilateral occlusion of the right main pulmonary artery, which both facilitated hemostasis and helped us evaluate tolerance to pneumonectomy. We performed a completion pneumonectomy, and he was eventually discharged to home.

A 62-year-old man was referred to our hospital because of an abnormal shadow in the right upper lung field. CT revealed the tumor measuring 18 mm in diameter in the right S1. 3D-CT on preoperative examination suggested that the right superior lobar bronchus was formed by B1a and B2a, and B1b+B2b and B3 arising from the middle lobe bronchus. Furthermore, 3D-CT showed a displaced anomalous B1b arising from the middle lobe bronchus and incomplete lobulation. He received an intraoperative rapid diagnosis of adenocarcinoma; thoracoscopic right upper and middle bilobectomy and lymphadenectomy were performed. In lung cancer surgery, we rarely encounter patients with a bronchial anomaly and the standard surgery for lung cancer with a displaced anomalous bronchus has not yet been established. 3D-CT was useful for safe operation in the case of a displaced anomalous bronchus.

The common complications after preoperative computed tomography-guided localization are pneumothorax and intrapulmonary hemorrhage. Air embolism is known as a rare but potentially fatal complication. We report two cases of short hook wire with nylon thread (marker) migration into the digestive tract through the bronchus. Case 1: The marker was placed on the day before surgery for a nodule in the left upper lobe. A chest radiograph taken after marking showed a slight pneumothorax. Although we could not find the marker in the thoracic cavity during surgery, we performed partial resection, because the nodule was palpable. Computed tomography revealed the marker in the descending colon. On the third postoperative day, it was found in the stool. Case 2: The marker was placed on the day before surgery for a nodule in the right middle lobe. A chest radiograph taken after the procedure showed no marker. We performed emergent computed tomography and located the marker in the small intestine. On the next day, surgery was performed as scheduled. The nodule was palpable; therefore, we initially performed partial resection. As the intraoperative pathological diagnosis was adenocarcinoma, we performed middle lobectomy. On the third postoperative day, an abdominal radiograph could not detect the marker. Because computed tomography could not reveal the marker in the colorectum on the fourth postoperative day, we considered that it had been discharged from body. In the two cases, the markers were expectorated through the bronchus and migrated into the digestive tract by unconscious swallowing. When performing computed tomography-guided localization, we should avoid peripheral bronchus and fix a nylon thread attached to a marker to the skin.

Displaced anomalous bronchi are rare bronchial abnormalities that may be accompanied by an abnormal branching of pulmonary vessels and abnormal lobulation, and therefore, should be sufficiently examined before surgery. We report our experience of a patient who underwent thoracoscopic left S³ segmentectomy for lung cancer with a left B¹⁺² displaced anomalous bronchus. The patient was a 71-year-old man in whom CT revealed a 1.3 cm part-solid nodule in the left S³. This nodule was suspected to be primary lung cancer, and thoracoscopic left S³ segmentectomy was planned. Preoperative three-dimensional computed tomography (3D-CT) revealed a left B¹⁺² anomalous bronchus displaced through the dorsal side of the pulmonary artery. We carefully examined the anatomical relationship between the bronchus and pulmonary vessels based on preoperative 3D-CT. Finally, thoracoscopic left S³ segmentectomy was successfully completed.

In 200X, we diagnosed a man in his 70s with Cushing syndrome, due to ectopic adrenocorticotropic hormone (ACTH) secretion. Abdominal computed tomography (CT) revealed a duodenal lesion that was suspected to be ATCH-producing based on adrenal venous sampling. He underwent a pancreatoduodenectomy; however, the lesion was histopathologically diagnosed as an inflammatory nodule. While the cause of ectopic ACTH production remained unknown, an adrenocortical steroid synthesis inhibitor was prescribed to control the adrenal cortical function.

Twelve years later, chest CT showed a 20-mm nodule in the lower lobe of his left lung. A thoracoscopic left lower lobe wedge resection was performed, and postoperative histological diagnosis revealed that it was an ACTH-producing typical carcinoid tumor. After the operation, he presented with hypoadrenocorticism with elevated ACTH levels, likely due to the long-term use of adrenocortical steroid synthesis inhibitors. Supplemental steroids normalized his serum ACTH levels. Neither the carcinoid tumor nor Cushing syndrome showed any signs of recurrence five years after the tumor was resected. This patient's ACTH-producing lesion was identified > 10 years after a diagnosis of ectopic ACTH syndrome was made, he was placed on steroid synthesis inhibitors and this resulted in adrenal insufficiency after the carcinoid tumor was resected. The treatment of ectopic ACTH syndrome primarily involves removal of the ACTH-producing lesion. Radiological workup, including somatostatin receptor scintigraphy, is essential for lesion detection. In particular, thoracic evaluation should be emphasized because carcinoid tumors and small cell carcinomas of the lung are the causes of approximately 50% of cases of ectopic ACTH production.

Malignant mesothelioma is classified as diffuse and localized malignant mesothelioma according to the mode of extension. Localized malignant mesothelioma is similar to diffuse malignant mesothelioma histologically and immunologically, but has different characteristics. The patient was a 63-year-old male. He was diagnosed with a malignant tumor and underwent surgery for diagnosis and treatment. A tumor was found in the hyperlobulation between the superior division and lingular segments, and there was no invasion or adhesion to the chest wall. We report the diagnosis of a localized biphasic mesothelioma of the visceral pleura because we encountered a rare case.

A 19-year-old male visited a nearby hospital because he had difficulty breathing, and a chest radiograph revealed a mediastinal mass. He was referred to our hospital for further examination and treatment. Contrast-enhanced chest computed tomography revealed a giant mass located in the anterior mediastinum and excluding the right atrium. MRI identified a high signal intensity mass in both T1- and T2-weighted images, and a low signal intensity mass in a fat suppression image. We diagnosed the tumor radiologically as a thymolipoma or thymoliposarcoma. We resected the giant mediastinal tumor completely via a hemi-clamshell approach. The resected specimen was 175×100 mm and weighted 800 g. Histologically, the tumor consisted of mature fatty tissue. There were no findings suggesting liposarcoma; therefore, the tumor was pathologically diagnosed as thymolipoma. The postoperative course was uneventful and the preoperative symptom of dyspnea also improved. We report this case with reference to the literature.