Yousuke Yamakawa

Thymectomy and malignancy

Three hundred ninety patients who underwent thymectomy for myasthenia gravis (MG) were followed up to investigate the development of associated malignancies. There were 102 patients with thymoma and 288 without thymoma. Malignant neoplasms were detected in ten patients, four of whom already had the tumor at the time MG was diagnosed. Thus, malignancy developed after thymectomy in six patients. Malignant fibrous histiocytoma (MFH) developed in three patients, as well as gastric cancer, gastric leiomyosarcoma, rectal cancer, liver cancer, lung cancer, breast cancer, and thymic carcinoid in one patient each. Nine of the ten malignancies developed in the thymoma group, and only one in the non-thymoma group. The predicted number of patients with malignancy was 2.63 in the thymoma group and 2.65 in the non-thymoma group. Our findings suggest that the presence of thymoma facilitates the occurrence of extrathymic malignancy, and that thymectomy never enhances the occurrence of malignancy but possibly inhibits it.

Pediatric and adult tracheobronchomalacia.

Twelve cases of tracheobronchomalacia (TBM) cases were reviewed: five were pediatric, and seven were adult, two of which were due to relapsing polychondritis (RPC). In pediatric TBM, the malacic segments were short. Resection of the malacic segment in one case and laryngotracheoplasty with autologous costal cartilage in one case were unsuccessful. However, aortopexy gained good results. Two cases managed conservatively experienced gradual improvement of their symptoms. In adult TBM, plication of pars membranacea was not effective in one case. The insertion of a stent was minimally effective in one case, and distinctly in one polychondritic case. The other four cases managed conservatively have deteriorated gradually. From these findings, a new classification system is proposed.

Pathogenesis of thymolipoma: report of three cases.

Three case reports of thymolipoma are herein presented. One patient presented with myasthenia gravis, while the other patients were asymptomatic. The tumors in our cases all had histopathologically different features: case 1, lipoma of the thymus; case 2, involuted thymic hyperplasia; and case 3, typical thymolipoma. The histopathological findings of thymolipoma are discussed in the context of the pathogenesis of thymolipoma.

Esophageal tracheobronchoplasty for membranous laceration caused by insertion of a dumon stent--maintenance of oxygenation by percutaneous cardiopulmonary support.

A 39-year-old man, whose airway was narrowed due to relapsing polychondritis, sustained a tracheobronchial injury during intubation with an internal stent. In the posterior membranous trachea and left main stem bronchus, a 5-cm longitudinal tear extended across the carina. Oxygenation was maintained by percutaneous cardiopulmonary support (PCPS) before and during the operation. An original esophageal tracheobronchoplasty for repair of the membranous laceration is described. Currently, the patient is asymptomatic 16 months after the surgery.

Elevated plasma thymosin-α1 levels in lung cancer patients

Objective: Prothymosin-a, the precursor of thymosin-a1, may play a role in cell proliferation, and the plasma level of thymosin-a1 may reflect the degree of proliferation of the tumor cells. Methods: Recently, a new sandwich immunoradiometric assay for thymosin-a1 was developed using monoclonal and polyclonal antibodies. In this investigation, we used this assay to measure plasma and tissue level of thymosin-a1 in 131 lung cancer patients. Results: We found that the mean plasma thymosin-a1 levels in lung cancer patients were higher than in normal individuals (PB 0.001). However, half of the patients showed normal levels. Thymosin-a1 levels correlated neither with the stage nor pathological subtype of the lung cancer, and did not decrease significantly in the 4 weeks after the resection of the tumor. Thymosin-a1 levels of lung cancer patients with another cancer were higher than those without evidence of other cancers (P0.03). Survival of patients with normal levels of plasma thymosin-a1 was significantly better than that with higher levels (P0.04). Conclusions: The plasma level of thymosin-a1 may be used as a marker for the prognosis of lung cancer patients. Further investigations are warranted to determine its role in the lung cancer.

Surgical Treatment for Hilar Type Multiple Squamous Cell Carcinoma.

肺門部多発扁平上皮癌5例を対象とし, 外科的治療の意義にっいて検討した.1例が3カ所, 4例が2カ所に病巣を有していたが, 全例少なくとも1病巣は早期癌であった.また同時性は4例, 異時性は1例であった.同時同側性では全病巣の切除が可能であった.同時両側性では進行癌を切除し早期癌に対し非観血的治療を施行することにより, 予後の向上を図れた.3例中2例で早期癌の再発を認めなかった.異時性多発癌の1例は気管支形成術を用いた術式により切除可能であった.