Myasthenia gravis aggravated by steroid-induced isolated mediastinal tuberculous lymphadenitis

Background: Myasthenia gravis (MG) is occasionally aggravated by chronic infection, of which there are many kinds.

Case report: We report herein the case of a 56-year-old woman with MG aggravated by the activation of isolated mediastinal tuberculous lymphadenitis (MTL) during corticosteroid administration. The possibility of MTL had been disregarded in the differential diagnosis of aggravation of MG weakness, because MTL without pulmonary manifestations is uncommon even in areas where tuberculosis is endemic.

Conclusions: This case suggests that chronic infections such as tuberculosis should be considered in myasthenic patients with progressive exacerbation if definite evidence for aggravating factors of MG is not obtained.