Analysis of 25 surgical cases of thymic neuroendocrine tumors and thymic carcinoma.

BACKGROUND: The purpose of this study was to evaluate the clinicopathological characteristics of patients who underwent surgical resection for thymic neuroendocrine tumors (TNET) or thymic carcinoma. METHODS: In this study, we retrospectively evaluated the clinicopathological characteristics of our surgical patients at Fukuoka University Hospital from January 1995 to December 2018. RESULTS: There were nine cases of TNET and 16 cases of thymic carcinoma. Regarding the pathological type, the TNET group included three atypical carcinoid cases, two large cell neuroendocrine tumor cases, two small cell carcinoma cases, and two other cases. The thymic carcinoma group included 15 squamous carcinoma cases and one case of adenosquamous carcinoma. Based on the Masaoka-Koga staging system, six TNET cases and 11 thymic carcinoma cases were stage III or IV. The complete resection rate was 77% in the TNET group and 81% in the thymic carcinoma group. Additional chemotherapy and/or radiotherapy was performed in five cases of TNET and 11 cases of thymic carcinoma. The five-year survival rate and five-year disease-free survival rate were 87.5% and 75.0% in the TNET group and 58.9% and 57.1% in the thymic carcinoma group, respectively, with no significant difference between the two groups (P = 0.248 and P = 0.894, respectively). In the univariate analysis, complete resection was a statistically significant prognostic factor (P = 0.017). CONCLUSION: In this study, no difference in prognosis was observed between TNET and thymic carcinomas. To understand the characteristics of these tumors, further case accumulation and multicenter clinical studies are needed. (243words).

The history of Japanese lung transplantation: the unique pathway to establishing the program and its initial success.

Japan is a unique country in terms of organ transplantation. Despite the impressive progress in transplant medicine achieved during the late 20th century in many Western countries, Japan was unable to implement a program for organ transplants from brain-dead donors due to persistent public distrust regarding the ethical understanding of "brain death as human death". In 1997, the Japanese Organ Transplant Law was enacted, and organ transplantation from brain-dead donors was finally legalized. However, this law was strongly opposed by religious leaders, philosophers, politicians, and even medical personnel who did not accept the idea that brain death is human death, so transplant physicians had to start performing transplants in the face of strong social resistance. The Japanese National Lung Transplant System was established based on the following three philosophies: (I) an institutional certification system based on strict standards; (II) a rigorous central monitoring system for transplant results; and (III) a third-party review system to determine eligibility for patient registration. The purpose of these policies was to avoid ethical issues at lung transplant institutes, and to achieve high-quality transplant results. The actual progress of Japanese lung transplantation has been quite unusual compared to other countries. The number of brain-dead organ donations was extremely limited at first, so more than 60% of lung transplants were performed as living-donor transplants during the first 9 years [1998-2006]. The number of brain-dead donations subsequently increased, particularly after the revision of the Organ Transplant Law in 2010 such that the majority of lung transplants are now performed as brain-dead transplantations. Regarding the results of lung transplants, the most recent national registry report indicated that a total of 668 lung transplants including 447 from brain-dead donors and 221 from living donors, had been performed as of 2018. The 5- and 10-year survival rates for brain-dead donor lung transplantation were 71.9% and 57.8%, respectively, with no significant difference between the living-donor and brain-dead-donor groups. These results are comparable with the outcome of preceding programs in the US and European countries.

Use of a radiofrequency identification system for precise sublobar resection of small lung cancers.

BACKGROUND: The incidence of sublobar resection is increasing because of the rise in the detection of small lung cancers. However, local recurrence needs to be addressed, and several methods are needed for the resection with secure margins of non-visible and non-palpable tumors. METHODS: We retrospectively reviewed the use of a radiofrequency identification (RFID) system in sublobar resection of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) at our institute. RESULTS: From June 2020 to June 2022, 39 patients underwent sublobar resection for AIS or MIA. The median age was 69 years (interquartile range, 64-76). Among the 39 patients, 24 were diagnosed with AIS and 15 with MIA. Segmentectomy, subsegmentectomy, and wedge resection were performed in nine, six, and 24 patients, respectively. The median size of the target tumor was 9.0 mm (8.1-12.9) and the median distance between the tag and the tumor was 2.9 mm (0-7.5). The median pathological surgical margin was 15.0 mm (10-17.5). Complete resection of all lesions was performed with a secure surgical margin. The median follow-up duration was 6 months, during which no local recurrence was detected in any of the patients. CONCLUSIONS: The RFID marking system accurately informed the surgeons of the tumor location and helped them to perform precise sublobar resection.

Development of a Novel Material to Promote Wound Healing at Bronchial Defects.

BACKGROUND: Bronchopleural fistula (BPF) is a critical complication that may progress to pneumonia and empyema, but optimal treatment remains uncertain. Our purpose was to develop a novel material for bronchial occlusion that can be used to treat BPF by blocking airflow and promoting wound healing. METHODS: Sponges were prepared in concentrations of 25, 40, and 50 mg/dL of silk-elastin by hydrophobic processing. Five adult Beagle dogs underwent right anterior lobectomy, and 5 underwent left posterior lobectomy. Silk-elastin sponges were placed at bronchial stumps of 8 dogs, and silicone plugs were placed at the stumps of 2 dogs as a control. RESULTS: Postoperative complications were not observed, except in 1 dog in which the silicone plug had been placed and which had massive subcutaneous emphysema at 4 weeks after operation. Histologic examination revealed that stumps were covered with connective tissue and that there was more regeneration of airway epithelium in the silk-elastin sponge group than in the silicone plug group. There were increased numbers of myofibroblasts around the bronchial stump occluded by silk-elastin sponges at 2 weeks after placement, which completely disappeared after 2 months, during which abundant neovascularization occurred. CONCLUSIONS: We showed that silk-elastin sponges can manage and promote regeneration of bronchial epithelium. Our results demonstrate that bronchial occlusion with a silk-elastin sponge is a promising option for treatment of BPF.

CDX2 Expression and Prognostic Factors of Resectable Pulmonary Large Cell Neuroendocrine Carcinoma.

BACKGROUND AND AIM: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare neoplasm, and its clinical features and management are still limited. We evaluated the clinicopathological factors, including CDX2 immunohistochemical expression, to predict survival in patients with LCNEC. PATIENTS AND METHODS: In all, 50 patients with LCNEC who underwent surgery at 4 institutes between 2001 and 2017 were included. Clinicopathological characteristics were evaluated for prognostic factors and statistically analyzed by Kaplan-Meier curve with a log-rank test or Cox regression models. We used immunohistochemical (IHC) analysis to determine the expressions of CDX2 and compared them with clinicopathological factors and survival. RESULTS: Sixteen of the 50 cases (32%) were CDX2 positive. No correlation was found between the CDX2 expression by IHC and clinicopathological factors. Multivariate analysis identified adjuvant chemotherapy (hazard ratio [HR] =2.86, 95% confidence interval [CI] = 1.04-8.16, P = .04) and vascular invasion (HR = 4.35, 95% CI = 1.21-15.63, P = .03) as being associated with a significantly worse rate of recurrence-free survival. CONCLUSION: CDX2 was expressed in 1/3 of LCNEC but not associated with prognostic factor. Adjuvant chemotherapy and vascular invasion were associated with a negative prognostic factor of LCNEC.

Adenoid cystic carcinoma with high-grade transformation forming spindle cell component of the submandibular gland.

Adenoid cystic carcinoma (AdCC) with high-grade transformation (AdCC-HGT) is rare, and AdCC-HGT with spindle cell component is particularly rare. The patient was a 65-year-old man with a 5 cm sized swelling of the right submandibular gland. Submandibular sialoadenectomy was performed. Histopathological findings mainly showed conventional AdCC, and minorly showed two other components: (1) the pleomorphic component, a proliferation of atypical pleomorphic epithelial cells forming solid or small clusters and accompanied by necrosis; (2) the spindle cell component, containing atypical spindle cells invading the stroma. Postoperative chemoradiotherapy was performed. Multiple right lung nodular lesions were found on the contrast-enhanced chest CT one month after the surgery. Thoracoscopic pulmonary resection was performed. The lung tumors exhibited a proliferation of atypical spindle cells, accompanied by necrosis. We considered that the spindle cell component of the AdCC-HGT of the submandibular gland developed lung metastases. The patient died seven months after submandibular sialoadenectomy due to respiratory failure. Although rare, our case highlights the importance of recognising spindle cell components in conventional AdCC; even if the area is small, these high-grade transformation areas can metastasise and become prognostic factors.