Microscopic Thymoma and Myasthenia Gravis
The term “microscopic thymoma” (MT) was first used by Rosai and Levine1 to describe an occasionally discovered microscopically sized thymic lesion with the histological features of a thymoma. Since then, to the best of our knowledge, other 5 cases of MT were described in patients suffering from myasthenia gravis (MG).2–4 Approximately 30–60% of patients with thymomas develop MG but probably this percentage is underestimated because of the possible presence of thymomas with very small dimensions in some myasthenic patients. In a previous paper we suggested the importance of establishing the unequivocal presence of a thymoma in myasthenic patients by obtaining histological samples of the entire gland, especially in those cases without macroscopical evidence of thymoma.3 In the current paper we describe the histopathological and immunohistochemical features of two cases of MT detected after sampling of the surgically removed thymuses from myasthenie patients.
KeywordsMicrowave Acetylcholine Prednisone Eosin Diaminobenzidine
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- 1.Rosai J, Levine GD. Tumors of the thymus. Atlas of tumors pathology, second series. Washington DC: Armed Forced Institute of Pathology, 1976.Google Scholar