A very rare case of spontaneous regression of basaloid squamous cell carcinoma of the lung.

Spontaneous regression of non-small cell lung cancer is relatively rare. Here, we present a very rare case of spontaneous regression of lung cancer which occurred in a patient with basaloid squamous cell lung cancer. To the best of our knowledge, this is the first report of such a case. A 76-year old man was referred to our hospital with nodules in the right upper lobe determined by chest computed tomography. The nodules spontaneously regressed during follow-up. Two years later, the tumor had regrown and the patient subsequently underwent surgery. The pathological findings showed basaloid squamous cell carcinoma. Stimulation of the immune system was considered to be the cause of the spontaneous regression and CD-8 positive and CD-4 positive lymphocytes might play an important role.

Rapid progressive spontaneous hemothorax caused by carcinoma of unknown primary: A very rare case.

We present a very rare case of spontaneous hemothorax which was caused by carcinoma of unknown primary. To the best of our knowledge, there are no other such cases reported worldwide. The patient was 72-year-old male who was referred to our department for massive hemothorax. We undertook surgical treatment for haemostasis, and found multiple tumours which led to the diagnosis of carcinoma of unknown primary as the cause of haemorrhage. The tumours increased and grew rapidly after surgery and hemothorax progressed despite our treatment. The patient died from disseminated intravascular coagulation caused by continuous bleeding on postoperative day 19.

Intraoperative control of air leak using a sutureless free pericardial fat pad covering method in lung cancer resection.

Here, we introduce a new method for intraoperative control of air leak using a free pericardial fat pad covering to lung damage with sutureless fixation. We covered the damaged lung tissue with a free pericardial fat pad with a polyglycol acid sheet and fibrin glue fixation. This method provides a good air leak controlling effect with the use of a free pericardial fat pad and relatively short operative time with sutureless fixation.

Intrathoracic lipoma of chest wall misdiagnosed as liposarcoma with malignant features based on radiological image and intraoperative findings.

Lipomas are common benign tumors, which are usually located in the subcutaneous tissue. It is relatively rare for lipoma to occur in the intrathoracic cavity, and it is clinically difficult to distinguish it from liposarcoma. We present the case of a 72-year-old man with a chest wall tumor preoperatively diagnosed as liposarcoma, with tumor enlargement with radiological image change to heterogenous and 18F-fluorodeoxyglucose positron emission tomography uptake. The tumor was resected along the chest wall, lung and diaphragm because of dense adhesions. The tumor was diagnosed as lipoma with fat necrosis and inflammatory changes.

Significance of the evaluation of tracheal length using a three-dimensional imaging workstation.

Background: Limited information is available on the total tracheal length and its other characteristics for tracheal surgery. This study aimed to investigate the reference value of tracheal length and assess its relationship with physiological variables. Methods: We measured the tracheal length of 215 patients (107 men and 108 women) who underwent contrast-enhanced computed tomography before thoracic surgery using a three-dimensional imaging workstation. Pearson correlation analysis and multiple linear regression analysis were performed to investigate the relationship between the total tracheal length (cervical and thoracic) and common physiological parameters. Results: The mean total tracheal length was 11.5±1 cm (range, 8.8-14.4 cm); 8% of the patients had a total tracheal length <10 cm. The cervical trachea was significantly shorter in men than in women (2.9±1.3 vs. 3.8±1.3 cm, P<0.001), whereas the thoracic trachea was significantly longer in men than in women (8.9±1.1 vs. 7.4±1.1 cm, P<0.001). Correlation analysis showed that the total tracheal length was positively associated with height in both sexes, while the height was positively associated with only cervical tracheal length. In the multiple linear regression analysis, the total tracheal length was influenced most by height, while cervical and thoracic tracheal lengths were influenced most by sex. Older age was also an independent contributor to a shorter cervical trachea and longer thoracic trachea in both sexes. Conclusions: The total tracheal length ranged from short to long in individuals, and characteristics of tracheal length varied with height, age, sex, and part of the trachea. We should thus be aware of the tracheal length of each patient for appropriate tracheal management.

Is using a consolidation tumor ratio 0.5 as criterion feasible in daily practice? Evaluation of interobserver measurement variability of consolidation tumor ratio of lung cancer less than 3 cm in size.

BACKGROUND: Consolidation tumor ratio (CTR) calculated as the ratio of the tumor consolidation diameter to the tumor maximum diameter on thin-section computed tomography (CT) of lung cancer has been reported as an important prognostic factor. It has also been used for treatment decision-making. This study aimed to investigate the interobserver variability of CTR measurements on preoperative CT and propose a clinically useful CTR-based classification criterion. METHODS: We enrolled 119 patients who underwent surgery for suspected or diagnosed small-sized lung cancer (≤3.0 cm in diameter). Nine doctors reviewed preoperative CT scans to measure CTR. Interobserver variability of CTR measurements was evaluated using the coefficient of variation (CV) and Fleiss' κ. The prognostic effect of the CTR-based classification was assessed using the Kaplan-Meier method. RESULTS: Interobserver variability of CTR measurement was the highest for tumors with the lowest CTR (CTR = 0); it decreased as CTR increased and reached a plateaued level of low variability (CV <0.5) at CTR of 0.5. We proposed a three-group classification based on the findings of CTR interobserver variability (CTR < 0.5, 0.5 ≤ CTR < 1, and CTR = 1). Interobserver agreement of the judgment of the CTR-based classification was excellent (Fleiss' κ = 0.81). The classification significantly stratified patient prognosis (p < 0.001, 5-year overall survival rates with CTR < 0.5, 0.5 ≤ CTR < 1, and CTR = 1 were 100, 88, and 73.8%, respectively). CONCLUSIONS: CTR 0.5 is a clinically relevant and helpful cutoff for treatment decision-making in patients with early-stage lung cancer based on high interobserver agreement and good prognostic stratification.

Thoracoscopic resection of pulmonary sequestration with carbon dioxide insufflation and indocyanine green.

We encountered a rare case of pulmonary sequestration supplied from the right renal artery, which was resected by video-assisted thoracic surgery with carbon dioxide insufflation and indocyanine green-guided technique. A 41-year-old woman with intralobar pulmonary sequestration supplied from the right renal artery was referred to our department. At the time of surgery, we used carbon dioxide insufflation to improve the manoeuvrable workspace for shutting off aberrant arteries and indocyanine green fluorescence guidance to differentiate the boundary of the sequestered lung from the normal lung. These procedures helped in the efficient resection of the lesion.

Preemptive Intercostal Nerve Block as an Alternative to Epidural Analgesia.

BACKGROUND: The necessity of thoracic epidural analgesia (TEA) during minimally invasive surgery (MIS) remains unclear. We investigated TEA efficacy in MIS versus thoracotomy and the noninferiority of a preemptive intercostal nerve block (ICNB) to TEA in MIS. METHODS: We investigated 393 patients who underwent lung resection, with and without TEA, between 2014 and 2019 (242 MIS, 151 thoracotomy) and 93 patients who underwent MIS with ICNB between 2019 and 2020. To address selection bias 70 TEA and 70 ICNB patients were propensity score matched. Endpoints were pain score during hospitalization, postoperative complications, duration of operating room use, analgesia-related adverse effects, and use of supplemental pain medication. RESULTS: One-third of patients with MIS discontinued TEA on postoperative day 1 or earlier; those with early TEA discontinuation reported worse pain the next day. TEA was associated with lower pain scores compared with non-TEA, regardless of surgical invasiveness, and a lower complication risk in patients with thoracotomy but not MIS. For MIS, ICNB was associated with an equivalent pain score on postoperative day 1, lower average pain score during hospitalization, shorter duration of operation room use, less frequent use of supplemental pain medication, and similar risk of postoperative complication and analgesia-related adverse effects compared with TEA after matching. CONCLUSIONS: Given early TEA discontinuation after MIS and ICNB's noninferior pain relief, preemptive ICNB can be an alternative for TEA in patients undergoing MIS.

Non-incisional pleurectomy/decortication for malignant mesothelioma after cardiac surgery.

A 70-year-old man diagnosed with right-sided malignant epithelial pleural mesothelioma, underwent pleurectomy/decortication after three courses of neoadjuvant chemotherapy. He had a history of mitral valve replacement and maze procedure with median sternotomy, and the procedures resulted in strong adhesion from the apex to the mediastinal side. In particular, the peeling of the area where the tumor invaded the pericardium required the most attention; however, the involved pericardium could be partially resected without damaging the right atrium. Finally, en bloc macroscopic complete resection with the entire pleura was successfully performed without conversion to extrapleural pneumonectomy.

Impact of counterclockwise rotation of the right middle lobe following right upper lobectomy.

OBJECTIVES: Following right upper lobectomy, the right middle lobe may shift towards the apex and rotate in a counterclockwise direction with respect to the hilum. This study aimed to investigate the incidence and clinical impact of middle lobe rotation in patients undergoing right upper lobectomy. METHODS: From January 2014 to November 2018, 82 patients underwent right upper lobectomy at our institution for lung cancer using a surgical stapler to divide the minor fissure. Postoperative computed tomography scans evaluated the counterclockwise rotation of the middle lobe, in which the staple lines placed on the minor fissure were in contact with the major fissure of the right lower lobe (120° counterclockwise rotation). Clinicoradiological factors were evaluated and compared between patients with and without middle lobe rotation. We also reviewed surgical videos in patients with middle lobe rotation to evaluate the position of the middle lobe at the end of surgery. RESULTS: Nine patients had a middle lobe rotation (11%), where 1 patient required surgical derotation. Patients with middle lobe rotation were significantly associated with more frequent right middle lobe atelectasis and severe postoperative complications compared with those without rotation. A surgical video review detected potential middle lobe rotation at the end of the surgery. CONCLUSIONS: Middle lobe rotation without torsion following right upper lobectomy is not rare, and it is associated with adverse postoperative courses. Careful positioning of the right middle lobe at the end of surgery is warranted to improve postoperative outcomes.

Postoperative chylothorax following lung cancer surgery with an aberrant course of thoracic duct: a case report.

Postoperative chylothorax occurs relatively rarely after pulmonary resections, often caused intraoperatively by injury to the thoracic duct. We describe a case of postoperative chylothorax after lung cancer surgery with an aberrant thoracic duct course. A 66-year-old man showed abnormal findings on chest computed tomography (CT) during health screening and was suspected with primary lung cancer. Then, he underwent a right upper lobectomy with mediastinal lymph-node dissection. The histopathological findings confirmed lung adenocarcinoma. However, the patient developed a postoperative chylothorax and underwent revision surgery. An abnormally running thoracic duct, which was expected to flow into the right venous angle, was found at the cranial side of the right superior mediastinal dissection area and was clipped. Considering the many variations in the route of the thoracic duct, thoracic surgeons should remain alert for postoperative chylothorax when performing lung cancer surgery with mediastinal lymph-node dissection and prepare treatment strategies accordingly.

Usefulness of SS18-SSX antibody as a diagnostic marker for pulmonary metastatic synovial sarcoma.

BACKGROUND: The novel SS18-SSX fusion-specific antibody is reported to have high sensitivity and specificity for the diagnosis of primary synovial sarcoma (SS), which often metastasizes to the lung. Thus far, no study has validated the diagnostic efficacy of SS18-SSX antibody for pulmonary metastatic SS. Therefore, we aimed to investigate the usefulness of the SS18-SSX antibody in the diagnosis of pulmonary metastatic SS. METHODS: We evaluated the immunohistochemistry of SS18-SSX fusion-specific antibody (E9X9V) in 10 pulmonary metastatic SS cases and the corresponding five primary sites (four limbs and one mediastinum) in five patients, for whom SS was already diagnosed and confirmed by fluorescence in-situ hybridization in the metastatic and primary sites, and in 93 clinical and histologic mimics including 49 non-SS, pulmonary metastatic sarcomas, 39 primary lung cancers, and five intrathoracic solitary fibrotic tumors. All specimens were surgically resected at Shinshu University Hospital during 2001-2019. For primary and metastatic SS, we also evaluated SS18-SSX immunohistochemistry using needle biopsy and touch imprint cytology specimens from the primary site. RESULTS: SS18-SSX staining was diffusely-strongly positive in all 10 pulmonary metastatic SS cases and the corresponding five primary sites; whereas, it was negative in all 93 clinical and histologic mimics (100% sensitivity and 100% specificity). Further, SS18-SSX staining was also sufficiently positive in the biopsy and cytology specimens. CONCLUSIONS: Immunohistochemistry of the SS18-SSX fusion-specific antibody is useful for the differential diagnosis of pulmonary metastatic SS in clinical practice. This simple and reliable method has the potential to replace traditional genomic tests. However, further studies are warranted in this regard.

Growing thymic granuloma adjacent to a thymic cyst mimicking malignancy: a case report.

An association between thymic cyst and thymic epithelial malignancy has been previously reported. However, several case studies have reported granulomas in the thymus with high metabolic activity, mimicking thymic malignancy. Additionally, an inflammatory response provoked by the rupture of cyst walls has been proposed as a pathogenesis of cholesterol granuloma in the thymus. However, the natural growth history of thymic granuloma remains unclear. We herein report the first case demonstrating the natural growth history of a thymic granuloma adjacent to a thymic cyst. Ten-year follow-up of the thymic cyst revealed a growing nodular lesion with high metabolic activity adjacent to the cyst. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) showed a maximum standardized uptake value of 12.1 in a 2.5-cm solid mass. We performed total thymectomy given a high suspicion of a malignant thymic epithelial tumor. Histopathologic examination revealed a cholesterol granuloma in the thymus, which was directly connected to the thickened region of the cystic wall through a rupture of the wall. This case highlights the importance of considering thymic granuloma as a differential diagnosis for a growing anterior mediastinal nodule with high metabolic activity. Further, the clinical course and histopathologic findings of this case provide supporting evidence for the proposed pathogenesis of thymic granuloma.