Prediction of improvement after extended thymectomy in non-thymomatous myasthenia gravis patients.

BACKGROUND: It is popularly believed that myasthenia gravis (MG) patients show acetylcholine receptor antibody (AChRAb) production associated with the thymus (germinal centers, approximately 80%). It has been suggested that thymectomy can remove the area of autoantibody production. This study aimed to determine whether the solid volume of the thymus calculated using three-dimensional (3D) imaging could be used to predict the efficacy of thymectomy. Additionally, the study assessed the relationships of the solid volume with germinal centers, change in the serum AChRAb level, postoperative MG improvement, and prednisolone (PSL) dose reduction extent. METHODS: This retrospective study included 12 consecutive non-thymomatous MG patients (9 female and 3 male patients), who underwent extended thymectomy at our institution over the last 10 years. The mean patient age was 43.3 ± 14.2 years (range, 12-59 years). The study assessed the number of germinal centers per unit area, change in the serum AChRAb level, postoperative MG improvement, PSL dose reduction extent, and solid volume of the thymus. RESULTS: The number of germinal centers per unit area was significantly correlated with the solid volume of the thymus. The PSL dose reduction extent tended to be correlated with the solid volume. CONCLUSIONS: Our findings suggest that the solid volume of the thymus can possibly predict steroid dose reduction. Additionally, the solid volume of the thymus in 3D images is the most important indicator for predicting the efficacy of extended thymectomy.

[Pulmonary resection in renal cell carcinoma metastasis;the influence of histologic atypia of the metastatic focus on preoperative or perioperative diagnosis].

UNLABELLED: The diagnostic potential of histological atypia grades in distinguishing between primary lung tumors and renal pulmonary metastases. OBJECTIVE: In cases of pulmonary resection for renal cell carcinoma patients, both the preoperative and perioperative diagnosis of lung cancer may be complicated by the need to distinguish between a primary lung tumor and metastatic renal tumor. The degree of histological atypia (grade) of the suspected metastatic focus may indicate the source of the lesion. The aim of this study was to evaluate the preoperative and perioperative diagnostic potential of histological atypia in determining the origin of lung tumors. STUDY DESIGN: Five cases that involved surgery for suspected lung metastasis from renal cell carcinoma were investigated. RESULTS: In cases for which the precise diagnosis of the metastatic focus was uncertain, histological atypia of the metastatic focus was of grade 3, whereas that of the primary renal cancer was of grade 1 or 2. CONCLUSION: These findings suggest that lung metastases with grade 3 histological atypia are suspected to be primary lung tumors on the basis of preoperative imaging, and preoperative distinction between primary lung tumors and metastases from renal cell carcinoma is therefore difficult. In such cases, the choice of operative method needs to be very carefully considered.