Case Report of Subclinical Myasthenia Gravis Associated with Castleman Disease.

Background: Castleman disease is a lymphoproliferative disorder of uncertain origin that is most commonly found in the mediastinum. It is classified based on pathological features into hyaline-vascular, plasma cell, and mixed variants. An association between Castleman disease and myasthenia gravis very rarely has been reported, except of the hyaline variant type, because it is associated with various clinical abnormalities. Castleman disease typically is diagnosed based on an incidental radiology finding of enlarged local lymph nodes, which result in compression symptoms. Case Report: Here, we report the case of a 31-year-old Saudi woman who presented with a 2-year history of exertional dyspnea associated with mouth and eye ulcers. She had no other associated symptoms, such as muscular weakness, rapid fatigue, or drooping eyelids. She was referred to our institution for further investigation and management and was diagnosed with myasthenia gravis after testing positive for acetylcholinesterase antibodies. A computed tomography (CT) scan then was performed, which showed an enlarged thymus gland. The patient eventually underwent a bilateral thoracoscopic thymectomy. Conclusions: The aim of the present report was to add to the literature by presenting a rare case of asymptomatic subclinical myasthenia gravis associated with Castleman disease. The findings underscore the importance of considering Castleman disease in an asymptomatic patient who has a mediastinal mass and avoiding an unusual intraoperative occurrence such as massive bleeding by performing a preoperative biopsy and angiography. [ABSTRACT FROM AUTHOR]