Background: Cholesterol granuloma in the mediastinum is rarely observed, accounting for 1% of all mediastinum tumors. There have been only a few reports of multifocal cholesterol granulomas of the thymus. We herein report a rare case of multifocal cholesterol granuloma in the thymus that was incidentally detected during follow-up of an aortic aneurysm. Case presentation: The patient was a 70-year-old man with dyslipidemia and hypertension who was referred to our hospital to undergo an operation for chest aortic aneurysm. Preoperative computed tomography (CT) showed 4 lesions in the anterior mediastinum measuring up to 4 cm in size with slight contrast enhancement and spotty calcification. Therefore, a thymoma, bronchogenic cyst, or lymphangioma were considered as the preoperative diagnosis. The patient underwent total thymectomy under thoracotomy followed by aortic arch replacement for the aortic aneurysm. The pathological diagnosis was multifocal cholesterol granulomas in the thymus. Conclusions: Cholesterol granulomas should be included in the differential diagnosis of cystic tumor in the mediastinum, especially in patients with basal disease such as dyslipidemia and hypertension, which may lead to aortic aneurysm. Furthermore, complete surgical resection and a detailed histological evaluation are important for the accurate diagnosis and treatment.

Background: Pleuroperitoneal communication (PPC) is rarely observed, accounting for 1.6% of all patients who undergo continuous ambulatory peritoneal dialysis (CAPD). Although there have been several reports concerning the management of this condition, we have encountered several cases in which control failed. We herein report a valuable case of PPC in which laparoscopic pneumoperitoneum with video-assisted thoracic surgery (VATS) was useful for supporting the diagnosis and treatment. Case presentation: The patient was a 58-year-old woman with chronic renal failure due to chronic renal inflammation who was referred to a nephrologist in our hospital to undergo an operation for the induction of CAPD. Post-operatively, she had respiratory failure, and chest X-ray and computed tomography (CT) showed right-sided hydrothorax that decreased when the injection of peritoneal dialysate was interrupted. Therefore, PPC was suspected, and she was referred to our department for surgical repair. We planned surgical treatment via video-assisted thoracic surgery. During the surgery, we failed to detect any lesions with thoracoscopy alone; we therefore added a laparoscopic port at her right-sided abdomen near the navel and infused CO₂ gas into the abdominal cavity. On thoracoscopy, bubbles were observed emanating from a small pore at the central tendon of the diaphragm, which was considered to be the lesion responsible for the PPC. We closed it by suturing directly. Conclusions: VATS with laparoscopic pneumoperitoneum should be considered as an effective method for inspecting tiny pores of the diaphragm, especially when the lesions responsible for PPC are difficult to detect.

Background: Intrathoracic mesothelial cysts are congenital lesions induced by the abnormal development of the pericardial coelom. There have been a few reports of giant mesothelial cyst of the superior mediastinum, but the preferred treatment remains a controversial topic. We herein report a rare case of successful removal of giant mesothelial cyst that was incidentally detected during a medical checkup. Case presentation: A 53-year-old man with a feeling of mild chest tightness was referred to our hospital for the evaluation of an abnormal shadow of the mediastinum on chest X-ray. Computed tomography showed a multilocular, homogenous, large cyst in the superior mediastinum measuring 18 cm in size without contrast enhancement and with spotty calcification, and magnetic resonance imaging showed a low intensity on T1-weighted images and high intensity on T2-weighted images. Therefore, a cystic thymoma, thymic cyst, lymphangioma, cystic teratoma or pericardial cyst was suspected as the preoperative diagnosis. Despite mild symptoms, the patient underwent total thymectomy under median sternotomy for an appropriate diagnosis and treatment. The pathological diagnosis was giant multilocular mesothelial cyst. Conclusions: Intrathoracic mesothelial cyst is a benign cyst and generally asymptomatic, but can sometimes induce critical chest clinical symptoms if untreated, depending on its size. In our case, complete surgical resection and a detailed pathological evaluation was effective for making the appropriate diagnosis and delivering treatment. In addition, an immunohistological evaluation is effective for diagnosing mesothelial cysts when it is difficult to distinguish the cyst from other cystic lesions.

Background: Teratoma is the second most common mediastinal neoplasm, but malignant transformation in mature teratomas is uncommon, and cases of carcinoid tumor with teratoma are described in only a few studies. In addition, multilocular thymic cyst associated with mature mediastinal teratoma is also a rare entity. There have been no reports of case with the coexistence of these three pathological lesions. Case presentation: The patient was a 24-year-old man who was referred to our hospital due to a 2-day history of left shoulder pain, a feeling of severe chest tightness and high fever. Pre-operative computed tomography (CT) showed a large, fluid-filled and well-demarcated multilocular cyst in the anterior to superior mediastinum measuring up to 12 cm in size. Contrast-enhanced CT also revealed that the tumor contained a solid component with slight contrast enhancement and spotty wall-thickening septation. Therefore, cystic thymoma, thymic cyst, cystic teratoma, or germ cell tumor with an inflammatory reaction were considered as differential diagnoses. The patient underwent tumor extirpation under median sternotomy. The pathological diagnosis was multilocular thymic cyst with mature teratoma including carcinoid tumor (Grade 2) in the mediastinum. Conclusions: The relationship between thymic cyst, teratoma and carcinoid tumor is unclear at present; therefore, further research is needed to clarify the relationship between these entities. In this report, we present a case of multilocular thymic cyst with mature teratoma including a carcinoid component in the mediastinum that was detected by complete surgical resection.

Background: Solitary fibrous tumor of the pleura is rarely observed, accounting for 1% of all mediastinum tumors. There have been only a few reports of preoperative embolization for hypervascular tumors around the artery of Adamkiewicz (AKA). We report a rare case of solitary fibrous tumor for which transcatheter embolization was successfully performed before surgical resection. Case presentation: A 66-year-old woman with sudden-onset back pain was referred to our hospital for the evaluation of a left intrathoracic abnormal shadow on chest X-ray. Preoperative computed tomography (CT) showed a large, posterior mediastinal, paravertebral, and well-demarcated mass with high contrast enhancement and significant vascularization fed by the intercostal artery (ICA), measuring 8.1 × 7.6 × 6.4 cm. Therefore, solitary fibrous tumor, unicentric Castleman disease, or paraganglioma was included in the differential diagnosis. The patient underwent preoperative transcatheter arterial embolization followed by surgical extirpation. Thanks to the appropriate assessment of the anatomy, we could resect the tumor safely. The pathological diagnosis was solitary fibrous tumor of pleura. Conclusions: We recommend preoperative transcatheter arterial embolization (TAE) for hypervascular tumors close to the AKA that may require surgical removal; to reduce intraoperative hemorrhage, the AKA should be accurately detected during surgery.

Thin-slice high-resolution computed tomography (CT) has improved the detection of small pulmonary nodules, increasing the demand for minimally invasive diagnostic and therapeutic resection. While lobectomy with lymph node dissection remains the standard surgical approach for many patients with resectable non-small cell lung cancer, accumulating evidence supports sublobar resection for selected small, peripheral, and ground-glass-dominant lesions when sufficient margins are achievable. In thoracoscopic and robotic surgery, localization of nodules ≤10 mm or lesions located >5 mm from the pleural surface can be challenging, and failure to identify the target may lead to conversion, larger resection than intended, or prolonged operative time. Several localization strategies have been developed, including CT-guided percutaneous wire/coil/dye marking, bronchoscopic dye mapping, and virtual-assisted lung mapping (VAL-MAP), robotic-assisted bronchoscopic dye or fiducial localization, radiofrequency identification microtag systems (Surgical Real-Time FInger Navigation and Detection) that provide real-time depth information, and single-stage intraoperative CT-guided marking and resection in hybrid operating rooms. This review synthesizes representative evidence and published outcome ranges, and compares workflows, marker-to-lesion precision metrics, complication profiles, operational burden, and cost structures. We emphasize the practical contrast between two-stage and single-stage workflows, the access-route differences between transthoracic and transbronchial techniques, and the need to report localization-to-incision “time at risk”. We also present an expert-consensus decision algorithm aimed at facilitating tailored selection of localization strategies for modern minimally invasive thoracic surgery.