IP Indian Journal of Immunology and Respiratory Medicine 2020;5(1):65–67 Content available at: iponlinejournal.com IP Indian Journal of Immunology and Respiratory Medicine Journal homepage: www.innovativepublication.com Case Report A case report of a rare benign mature teratoma of the mediastinum in a young adult Akor Alexander Agada 1, *, Ameh Abdul 1 1 Dept. of Internal Medicine, University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria ARTICLE INFO Article history: Received 14-01-2020 Accepted 26-02-2020 Available online 13-04-2020 Keywords: Benign Teratoma Mediatstinum ABSTRACT Mature teratoma is a rare, nonmalignant tumor of the mediastinum. We report, a rare case of a benign mature teratoma of the anterior mediastinum in a young Nigerian adult. She presented with symptoms of an expanding mass in the mediastinum this included centrally located dull chest pain, dry cough, and weight loss of 4 months duration. The review of the other system and physical examination findings was unremarkable. She had a contrast-enhanced computerized tomogram scan of the chest, which revealed a well circumscribe lobulated, soft tissue mass with fatty foci and calcifications. She had a median sternotomy with excision of the tumor. The histopathological examination of the sections showed structures lined by structures derived from ectodermal, mesodermal, and endodermal germ layers. Ectoderm components included skin sebaceous glands, hair, follicles, choroid coats, and brain tissue. Smooth muscle bundles hyaline cartilage, adipose tissue, and bone were mesodermal derivatives. Endodermal derived components included respiratory epithelium, intestinal mucosa, and seromucous glands. No atypical structure or proliferation was seen. The diagnosis of benign mature teratoma of the mediastinum was confirmed. A high index of suspicion, proper evaluation of patients is key to quick diagnosis and prompt management in such cases. © 2020 Published by Innovative Publication. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by/4.0/) 1. Introduction The mediastinum is the most frequent extra gonadal site of germ cell tumors. About 5-10% of all germ cell tumors found in the mediastinum, with about 95% of the tumors located in the anterior compartment (anterior mediastinum). 1–3 Benign teratomas of the mediastinum are rare but by far the most common germ cell tumor. It accounts for 50-70% of mediastinal tumors. Benign germ cell tumors are considered as benign teratomas or dermoids if they are primarily solid in-consistency. 4 They are regarded as epidermoid or dermoid cysts if they are mainly cystic. 4 There are two types of benign teratomas based on histopathological characteristics; this includes the mature (well-differentiated) and immature (poorly differentiated) tumors originating from any of the germ cell lines. We report the case of a benign matured teratoma in an 18-year-old * Corresponding author. E-mail address: alexander.agada@uniabuja.edu.ng (A. A. Agada). undergraduate student. 2. Case Report An 18 years old undergraduate student, presented to the general outpatient clinic with a history of a dull ache located in the retrosternal area of the chest, the pain was non-radiating, no postural relationship and no known relieving or aggravating factors. The chest pain was associated with dry cough and weight loss but no accompanying history of fever, drenching night sweats. No difficulty with breathing, dyspnea on exertion, orthopnea, or paroxysmal nocturnal dyspnea. A review of the other systems did not provide any additional information. Physical examination was unremarkable. Based on the patient’s clinical presentation, she was commenced on triple therapy treatment for peptic ulcer disease by the general practitioner. The initial sputum test isolated streptococcus species. Fungal study and the Gene Xpert results returned https://doi.org/10.18231/j.ijirm.2020.014 2581-4214/© 2020 Innovative Publication, All rights reserved. 65