A Study Of The Relationship Between Thymoma And Myasthenia Gravis

Objective To investigate the relationship between the latist WHO criteria, other classifications of thymic epithelial tumours(TET), the Masaoka pathological stages, and postoperative prognosis of myasthenia gravis(MG). ②To analyse the relavence between the image and the pathological changing of thymus. ③To analyse the clinical diferences between myasthenia gravis associated with thymic epithelial tumours(MGT) and myasthenia gravis associated with thymic hypersia (MGH) and myasthenia gravis associated with normal thymus (MGN). ④To study the indication of thymeetomy for patients with purely ocular myasthenia gravis(POMG). Methods To analyse the pathological sections and clinical manifestations of 105 cases with thymoma and 38 cases with thymic hypersia who, and clinical manifestations of 113 cases with myasthenia gravis from 178 cases with thymoma or/and MG from 1974 to 2000. Results ①With the -.7- analyzation of 32 cases of MGT among the 105 cases with thymoma, we found that WHO types, Masaoka clinical stagings, and Osserman clinical classification had a strong correlation with postoperative crisis, wbile Levine-Rosai's clinicopathological classification and traditional histological classification did not have any obvious relevance with Osserman clinical classification, the incidence rate of MG, and postoperative crisis. ②In 77cases with the clinical pathological results of thymus, The sensitivity, specificity,and veracity rates of X-ray onMGH and MGT are 4/31 (12.90%) 4/4 (100%) ,4/31 (12.90%) , and 28/36 (77.78%) , 28/28 ( 100% ) , 28/36 ( 77.78% ) respectively. The sensitivity, specificity,and veracity rates of CT onMGH and MOT are 25/30 ( 83.33%), 25126 ( 96.15%) , 25/31 ( 80.65%) and 32/34 ( 94.12%) , 32/33 ( 96.97%) , 32/35 (91.43%) respectively. ￤e had compared 40 cases of MGT, 32 cases of MGH, and 28 cases of MON on the constituent ratio of sex, age, first symptom, and clinical classification, the postoperative crisis, -8- and operation prognosis. @There was a striking discrepancybetween the operation group and nonoperation group(MGT:P<0.05, MGH:P<0.l0 ) on the effective rate, and nosignificant difference on the recovery rate. Conclusion OWHO types, Masaoka clinical stagings, and Ossermanclinical classification are three important prognostic factors forpostoperative crisis. @ The sensitivity of X-ray or CT onthymic disorders is not very high, especially on thymichypersia. It is not necessary for thymectomy in myastheniagravis to have a positive result of images from X-ray or CT.@There are a lot of differences between MGT and MGH onthe constituent ratio of sex, age, the postoperative crisis, andoperation prognosis. We infer that their pathogenesis may bedifferent. @The indication of thymectomy for purely ocularMG should be strictly controlled.