HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Masanori Tsuchida Jun-ichi Hayashi Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tsuchida, M. Articles by Hayashi, J.-i. Search for Related Content PubMed Articles by Tsuchida, M. Articles by Hayashi, J.-i.

Ann Thorac Surg 2000;69:314
© 2000 The Society of Thoracic Surgeons

---

Correspondence

Reply

^a Department of Thoracic and Cardiovascular Surgery, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata City 951-8510, Japan

e-mail: mtsuchi{at}med.niigata-u.ac.jp

To the Editor

We appreciate the opportunity to reply to the comments by Dr Kirschner concerning our article [1].

As pointed out by Dr Kirschner, myasthenia gravis (MG) patients comprise a wide and heterogeneous population, even with respect to the pathology of thymus. Thus, the patients’ background should be considered when comparing the efficacy of treatment.

When we compared the young and elderly groups in our series, there were no statistically significant differences with respect to several parameters, including gender, Osserman classification, and pathology of the thymus. Furthermore, according to gender, 6 of the 10 males (60%) and 4 of the 15 females (27%) in the elderly group had thymoma, which is comparable with the young group, in which thymoma was present in 10 of the 18 males (56%) and 12 of the 51 females (24%). Thus, we did not encounter the same demographic distribution of thymomatous and nonthymomatous MG patients as reported by Compston and associates [2]. Recent reports have also indicated an increase in late-onset MG with no evidence of a relationship between thymoma and age [3, 4]. However, we did note gender differences with respect to Osserman classification between nonthymoma and thymoma elderly patients, such that there were more women who tended to have a lower Osserman classification (IIA) among nonthymomatous patients. On the other hand, thymomatous patients tended to comprise more men, with a more severe Osserman classification (IIB). It is also of note that the surgical results did not differ remarkably between nonthymomatous and thymomatous patients; 14 improved (including 2 delayed deaths) and 1 worsened among the 15 nonthymomatous patients. Among the 10 thymomatous patients, 2 went into remission and 6 showed improvement. Extended thymectomy in thymomatous patients refers to excision of the entire anterior mediastinal fatty tissue including the thymus and thymoma. In our series, thymoma is defined as a tumor composed of neoplastic epithelial cells and lymphocytes, and does not include thymic carcinoma, thymic carcinoid, or thymolipoma. In addition, we did not observe a rise in the titers of acetylcholine receptor antibodies after extended thymectomy for thymomatous myasthenia gravis. In summary, we reexamined our results from a different point of view based on Kirschner’s comments by dividing elderly patients into thymomatous and nonthymomatous myasthenia gravis patients. Despite these modifications, we still came to the conclusion that surgery is indicated for both nonthymomatous and thymomatous elderly patients. We thank Dr Kirschner for his comments.

References

1. Tsuchida M., Yamato Y., Souma T., et al. Efficacy and safety of extended thymectomy for elderly patients with myasthenia gravis. Ann Thorac Surg 1999;67:1563-1567.[Abstract/Free Full Text]
2. Compston D.A.S., Vincent A., Newsom-Davis J., et al. Clinical, pathological, HLA antigen and immunological evidence for disease heterogeneity in myasthenia gravis. Brain 1980;103:579-601.[Free Full Text]
3. Aarli J.A. Late-onset myasthenia gravis. Arch Neurol 1999;56:25-27.[Abstract/Free Full Text]
4. Phillips L.D., 2nd The epidemiology of myasthenia gravis. Neurol Clin 1994;12:263-271.[Medline]

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Masanori Tsuchida Jun-ichi Hayashi Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tsuchida, M. Articles by Hayashi, J.-i. Search for Related Content PubMed Articles by Tsuchida, M. Articles by Hayashi, J.-i.