Localized Primary Thymic Amyloidosis Presenting as a Mediastinal Mass - A Case Report -

EBUS-TBNA diagnosis of localised amyloidosis presenting as mediastinal lymphadenopathy

Amyloidosis is a unique disease of localised or systemic deposition of the abnormal extracellular fibril. Localised amyloidosis generally takes a benign course, while systemic requires treatment. Adenopathy, especially mediastinal adenopathy, is an unusual manifestation of localised amyloidosis and often requires mediastinoscopy or surgical resection for diagnosis. With the advent of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), there is potential for a less invasive diagnostic approach. We report a rare case of localised mediastinal amyloidosis diagnosed by EBUS-TBNA.

Ocular Myasthenia Gravis Associated With Thymic Amyloidosis

A 45-year-old woman with ptosis and diplopia was found to have myasthenia gravis (MG) associated with amyloidosis of the thymus gland. Systemic MG is frequently associated with thymomas or thymic hyperplasia but has only once previously been reported in association with amyloidosis of the thymus. This case demonstrates that isolated ocular MG rarely may also be associated with amyloidosis of the thymus.

Localized thymic amyloidosis presenting with myasthenia gravis: case report

A mediastinal mass was incidentally found on chest radiography in a 46-yr-old woman who had had myasthenia gravis (MG) for 2 months. Computed tomography revealed a 4-cm in size, well-defined, and lobulating mass with nodular calcification that was located in the thymus. Microscopically, the mass consisted of diffuse amorphous eosinophilic materials. These deposits exhibited apple-green birefringence under polarized light microscopy after Congo red staining. Immunohistochemical analysis revealed that they were positive for both kappa and lambda light chains and negative for amyloid A. A diagnosis of localized primary thymic amyloidosis was finally made. After thymectomy, the symptoms of MG were controlled with reduced corticosteroid requirements. Localized thymic amyloidosis associated with MG has not been reported to date.