Non-sebaceous Lymphadenoma of the Thymus: a Case Report

Abstract Background: non-sebaceous lymphadenoma (NSL) is a rare benign tumor with a predominant lymphoid background within which is embedded solid or duct-like structures squamous epithelial nests, lacking of sebaceous differentiation. Non-sebaceous lymphadenoma most commonly arises within the salivary glands. However, Non-sebaceous lymphadenoma arises in the thymus have not been reported.Case presentation: A 53-year-old female patient, computed tomography (CT) scan of the chest for patient showed a nodular (19 ×13 × 16-mm) in the anterior mediastinum, and with mild homogeneous enhancement on contrast-enhanced CT. The patients underwent total thymectomy with removal of the anterior mediastinal nodule by thoracoscope via below the costal margin of the Xiphoid process. Microscopically, the tumor was composed of epithelial nests and prominent lymphoid stroma, with a capsule and clearly demarcated from the surrounding thymus tissue. The epithelial nests are arranged in solid nests or duct-like structures, lacking of sebaceous differentiation and cytological atypia. The pathological diagnosis was lymphadenoma, non-sebaceous type. There were no signs of recurrence 6 months after the surgery.Conclusions: There are very few reported cases of non-sebaceous lymphadenoma occurred in thymus in the medical literature. So accurate understanding of the histopathologic diagnosis of this rare tumor is important to avoid unnecessary overtreatment.