Introduction: A causal relationship between the thymus gland and myasthenia gravis (MG) has been assumed for decades. However, this relationship is still a matter of conjecture and speculations and awaits definitive proof. Recently, myoid cells have been considered as effectors in the pathogenesis of MG as well as thymic enlargement (thymolipoma, true thymic hyperplasia). Material and methods: we report a retrospective study about 6 cases of thymic enlargement with 4 cases of true thymic hyperplasia (TTH) and 2 cases of thymolipoma (TL). Aim: Our objective is to discuss the role of myoid cells in the pathogenesis of MG associated with thymic enlargement. Results: The majority of our patients were men with a sex ratio of 4/2. Only 2 patients had a past medical history consistent for MG. Myoid cells were found in all cases. Conclusion: Through our small study, the implication of myoid cells in the pathogenesis of the association MG-TL or TTH remains unproved.
This study contributes in the existing literature by enriching our knowledge about the pathogenesis of myasthenia gravis.
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