Takayuki Ibi

Diaphragmatic repair of two cases of hepatic hydrothorax using video-assisted thoracoscopic surgery

Hepatic hydrothorax is defined as the presence of a significant pleural effusion that develops in a patient with cirrhosis of the liver who does not have underlying cardiac or pulmonary disease. There are few published case reports dealing with hepatic hydrothorax treated surgically because patients with hepatic hydrothorax have end-stage liver disease. Recently, we treated two patients with refractory hepatic hydrothorax by directly suturing the diaphragmatic defects during video-assisted thoracoscopic surgery (VATS). During surgery, the diaphragmatic defects were identified using abdominal insufflation of saline with indocyanine green or carbon dioxide. After suture closure using fibrin glue, both right pleural effusions were improved. The patients’ postoperative courses were uneventful, and they did not require a drainage tube when they were discharged.

Choriocarcinoma of the lung: report of a case

In this report, a 27-year-old woman with a solitary pulmonary nodule is described. Because computed tomography-guided biopsy could not confirm the diagnosis, surgical treatment was performed by video-assisted thoracic surgery. Histological findings showed cytotrophoblasts and syncytiotrophoblasts, suggesting choriocarcinoma. However, there were no abnormal findings on gynecological examination, including ultrasonography, magnetic resonance imaging, and positron-emission tomography. Choriocarcinoma is a malignant neoplasm and can arise after a pregnancy, as a component of germ cell tumors, or in association with a poorly differentiated somatic carcinoma. Our patient, a young female with an antecedent gestation, has no recurrence after surgery. There were tumor emboli in pulmonary arteries and no component of primary lung carcinoma on histological examination. These findings indicate that the lesion was a metastasis of gestational choriocarcinoma. A rare case of a patient with metastatic gestational choriocarcinoma of a solitary pulmonary nodule without any uterine abnormality is presented.

Prognostic significance of PIK3CA and SOX2 in Asian patients with lung squamous cell carcinoma.

The recent development of human genome studies has demonstrated the possibility of alteration of several genes as oncogenic driver mutations of lung squamous cell carcinoma (SQCC). FGFR1, PIK3CA and SOX2 genes have been recognized as candidate driver genes of SQCC. The aim of the present study was to evaluate FGFR1, PIK3CA and SOX2 protein expression in SQCC and determine whether the expression of these can be used as prognostic biomarkers. We evaluated the relationships between FGFR1, PIK3CA and SOX2 expression by immunohistochemical analysis and overall survival in lung SQCC patients with stage I–III that originated from China, United States and Japan. FGFR1-positive, PIK3CA-negative and SOX2-positive staining each showed trends toward better survival, although the differences were not statistically significant in a Chinese cohort of 57 patients. Patients with PIK3CA-negative and SOX2-positive staining (PIK3CA−/SOX2+) showed better prognosis compared with those with PIK3CA-positive or SOX2-negative staining in the Chinese cohort (P=0.04). The robustness of PIK3CA−/SOX2+ classification as having prognostic significance was validated in an independent set of 66 Japanese cohort patients (P=0.007). Japanese SQCC patients with stage I were evaluated separately and PIK3CA−/SOX2+ cases had significantly better survival than the group with PIK3CA-positive or SOX2-negative status (P=0.03). In univariate and multivariable Cox proportional hazards models of Asian stage I patients, the PIK3CA−/SOX2+ classification was statistically significantly associated with survival and was an independent prognostic factor. Classification by PIK3CA and SOX2 protein expression is useful for predicting the prognosis of Asian patients with lung SQCC with stage I.

Use of the “Secrea (Hogy™)” sponge spacer in thoracoscopic surgery for lung cancer

We report a new technique involving the ‘‘Secrea (HOGY)’’ sponge spacer for right superior mediastinal node dissection for the treatment of lung cancer. This technique allows the surgeon to make space within the operative field. The ‘‘Secrea’’ makes the operation safer and reduces some of the technical difficulties associated with thoracoscopic surgery. Video-assisted thoracic surgery (VATS) has become much more common over the last decade. VATS results in less postoperative pain and a shorter period of hospitalization. We introduce the ‘‘Secrea’’ sponge spacer, which is elliptic-cylindrical in shape and is made of polyurethanic material (Fig. 1A). The Secrea comes in three sizes, which measure 60mm along the major axis 35mm along the minor axis 20mm in height, 50mm 30mm 15mm, and 40mm 25mm 15mm, respectively. The Secrea can be held with forceps and introduced into the thoracic cavity through a 12-mm trocar. It contains a non-X-ray penetrative string and a radiopaque marker, and it also remains heat-resistant at temperatures above 4008C. Its function is (1) to absorb fluid, (2) to allow fluid to be sucked through the moist Secrea, (3) to allow the adjacent fragile tissue to be pressed softly without adhering to it, and (4) to prevent electric scalpels and ultrasonic coagulating shears inflicting secondary injuries on organs and tissues. The Secrea endoscopic surgical spacer, which was codeveloped with Hogy Medical Co. Ltd, has already been used for laparoscopic surgery [1]. Before its present clinical application to thoracoscopic surgery, we performed several preliminary experiments using swine. The effectiveness of the Secrea was confirmed, as it allowed us to expose the great vessels and trachea easily via its placement under the vessels. In addition, we have subsequently found that it is also applicable to thoracoscopic surgery. The Secrea enabled us to make space in the operative field without the aid of an assistant during the dissection of the right superior mediastinal nodes. Below, we introduce a new thoracoscopic surgical technique involving the ‘‘Secrea’’ sponge spacer.

Klotho expression is correlated to molecules associated with epithelial‑mesenchymal transition in lung squamous cell carcinoma

Klotho is known as an anti-aging gene. We previously reported that the expression of Klotho is a postoperative prognostic factor for patients with lung large cell neuroendocrine carcinoma and lung small cell carcinoma. Recently, Klotho was shown to suppress the epithelial-mesenchymal transition (EMT). In the present study, we examined the association between the expression of Klotho and the regulation of EMT in lung squamous cell carcinoma. We immunohistochemically examined the expression of Klotho in patients with lung squamous cell carcinoma who had undergone surgical resection or photodynamic therapy. The immunohistochemical analysis showed that Klotho expression was observed not only in normal bronchial epithelial cells, but also in centrally located early lung cancers, which were all carcinomas in situ and were treated using PDT. However, in lung cancer patients with invasive and or advanced squamous cell carcinoma who had undergone a complete surgical resection, Klotho expression was observed in only 4 patients (13%). To elucidate the associations between the expression of Klotho and the expressions of EMT-related proteins, such as E-cadherin, N-cadherin, vimentin, and Snail, we transiently transfected GFP-Klotho plasmid DNA into the human squamous lung cancer cell line SQ5 and examined the expressions of these proteins of GFP-positive cells after sorting using flow cytometry. In SQ5 cells overexpressing GFP-Klotho, the expression of N-cadherin, which is a mesenchymal marker, was completely inhibited, compared with that in SQ5 cells transfected with the GFP vector. The overexpression of Klotho did not affect the regulation of either other mesenchymal markers (such as vimentin and Snail) or the regulation of an epithelial marker (E-cadherin). We concluded that the expression of Klotho was related to the degree of cancer invasiveness and that Klotho inhibits the expression of N-cadherin and regulates the EMT in lung cancer.

Mature teratoma of the posterior mediastinum: report of a case.

Mediastinal teratoma generally arises in the anterior mediastinum. Posterior mediastinal teratomas have been rarely reported to date, especially in adults. We report a case of posterior mediastinal teratoma in a 57-year-old woman. The pre-operative diagnostic work-up revealed a posterior mediastinal tumor with calcification and fluid components. The tumor, adhering to the descending aorta, was radically removed through video-assisted thoracic surgery. Histological examination was concluded for a mature teratoma with cystic change. The imaging features of posterior mediastinal teratomas are identical to those in the anterior mediastinum, except for their location. To be different from anterior mediastinal teratomas, benign teratomas in the posterior mediastinum are often involved with a major surrounding structure, including aorta, chest wall, and esophagus. When a posterior mediastinal tumor has the typical features of a mature teratoma in the pre-operative findings, the adhesion to the surrounding structure should be considered.

Atypical carcinoid localized at the bronchus accompanied by diffuse idiopathic pulmonary neuroendocrine cell hyperplasia in the distal lung: a rare case report

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is hyperplasia of noninvasive neuroendocrine cells originating from Kultchitsky cells. This is a rare pathological condition, suspected to be a precursor lesion of carcinoid, together with tumorlet. In the WHO histological classification (4th edition) revised in 2015, DIPNECH was added to the category that includes neuroendocrine tumors. Our patient was a 77-year-old woman who initially visited another doctor because of coughing. Chest CT revealed a mass occluding the right intermediate bronchial trunk, and bronchial carcinoid was suspected from biopsy findings, leading to referral of this patient to our department. The tumor was excised under a rigid bronchoscope for the purpose of making a definitive histological diagnosis and determining the extent of spread. The stalk portion of the tumor extended from the bifurcation of the middle and lower lobe bronchi in the membranous part of the intermediate trunk to the central side. The airway appeared to be almost completely occluded under bronchoscopy, but aeration from the periphery was maintained. Histopathologically, there was hyperplasia of oval atypical cells with relatively poor cytoplasm beneath the bronchial mucosa on HE staining, suggesting neuroendocrine tumor. Immunostaining revealed that these cells were positive for CD56, chromogranin A, and synaptophysin, and that there was moderate mitosis, leading to a diagnosis of atypical carcinoid. At a later date, radical surgery comprised of right pulmonary middle and lower lobectomy and lymph node dissection was performed. The final histopathological diagnosis was atypical carcinoid of the bronchus (pT1aN0M0, stage IA). There were multiple aggregations of atypical cells, measuring approximately 1-3 mm, along the airway around the bronchioles in the excised lung, indicating concomitant DIPNECH. The patient currently has no evidence of either recurrence or metastasis at 12 months after surgery, but we will continue meticulous follow-up.