Mature teratoma with somatic-type solid malignancy in the mediastinum: A case report of rare and poor prognosis tumour

Abstract

Background: Germ cell tumor with somatic-type solid malignancy is a germ cell tumor accompanied by a non-germ cell, the somatic-type malignant component in the form of sarcomas or carcinomas. These germ cell tumors are rare, accounting for only about 2% of all germ cell tumors in men. About 25-30% of these tumors occur in the mediastinum. These tumors are often located in the anterior mediastinum and occur in adult males with a peak incidence between 20-40 years. Case description: A 19-year-old female patient came with chief complaints of chest pain and shortness of breath about three months ago. Chest CT scan images showed a right lung reactive pneumonia with suspicious atelectasis at the second and third segments of the right lung. The image also showed a tumor mass with heterogeneous density at the mediastinum. Then thoracotomy surgery and tumor resection were performed. Macroscopically, there was a multicystic tumor mass measuring 14.0x11.0x6.5 cm, partly solid with 7.0x5.0x5.0 cm. Microscopic examination of the tumor mass showed three components of the germ layer, namely ectodermal, mesodermal and endodermal. No immature component appears. The tumor also contains neoplastic epithelial cells that form a solid, cribriform, acinic and papillary structure in the extracellular mucinous pool. Conclusion: Based on the clinical finding, radiologic, and routine histopathological examination, this case was concluded as mature teratoma with somatic-type solid malignancy in the form of mucinous adenocarcinoma.