Primary Thymic Mucinous Adenocarcinoma with Extensive Punctate and Amorphous Calcifications: A Case Report

Background: Primary thymic mucinous adenocarcinoma is an extremely rare and aggressive tumor with poor prognosis. The tumor may present as a heterogeneous solid or cystic mass accompanied by calcifications. However, clinical and radiologic features of the tumor are not well known due to the rarity of the disease, which makes accurate diagnosis difficult. Case Presentation: Here we present a rare case of primary thymic mucinous adenocarcinoma in the anterior mediastinum, including computed tomography (CT) and magnetic resonance imaging (MRI) findings. Chest computed tomography revealed a large anterior mediastinal mass with extensive calcifications with poor enhancement. MRI showed that anterior mediastinal mass showed intermediate signal intensity on T1-weighted images (T1WI), high SI on T2-weighted images (T2WI), and heterogeneous enhancement. Biopsy was performed and the anterior mediastinal tumor was diagnosed as thymic mucinous adenocarcinoma by histopathologic examination and immunohistochemical staining. Conclusion: Thymic mucinous adenocarcinomas could be included in differential diagnoses of anterior mediastinal tumors showing extensive calcification, and common imaging findings of mucinous adenocarcinoma such as T2 high signal intensity and heterogeneous enhancement on MRI may be helpful to diagnose thymic mucinous adenocarcinoma.