412 Mediastinal teratoma mimicking nonresolving pneumonia

A teratoma is a tumor of germ cell origin, composed of tissues or organ components from more than one germ cell layer. While mature forms are benign, immature teratomas may be malignant. It is important to emphasize there is always a risk of malignant transformation from the usually benign type. Mediastinal teratomas are uncommon in pediatric age and account for 7-11% of extragonadal teratomas. The specific localization of mediastinal teratoma is anterior or middle mediastinal compartment and rarely posterior mediastinum. Considering their incidence is very rare in children they can very often be misdiagnosed. They are difficult to diagnose in early stage due to very few nonspecific symptoms in the beginning and also can be asymptomatic. Due to complications while spreading to the adjacent structures, first manifestation can also be acute and dramatic. We report a case of 14-year-old boy, with severe neurodevelopmental deficit, who was initially suspected to have pleuropneumonia which was radiologically verified as paracardial homogenous consolidation in lower and middle right lung fields as well as an infiltrative attenuation at the base of the left lung. Within less than a month, after antimicrobial therapy, on follow up X-rays infiltrative lesion at the base of left lung completely regressed. However, homogeneous consolidation on the right along with a newly noticed calcification persisted, therefore lung CT scan was done. CT scan showed large tumor in the right thorax with characteristics of a teratoma. During right sided thoracotomy a large incapsulated tumor was found. Tumor occupied almost all total right hemithorax, it also adhered to surrounding structures, especially pericardium. Tumor was completely excised along with a part of pericardium, pathohistological diagnosis was mature cystic teratoma. Postoperative recovery was complicated by dependency on mechanical ventilation which was resolved by tracheostomy. However, new difficulties with spontaneous ventilation arose due to atelectases; these were treated with 5 bronchoscopies along with bronchoalveolar lavages. Eventually boy was referred to local hospital in good general condition with stable respiratory status. Rest of the postoperative recovery was uneventful. When facing nonresolving pneumonias clinician should always think of broader differential diagnosis. If pathological findings on radiological imaging persist, a clinician should consider organic causes of diseases and broaden diagnostic investigations so that both true diagnosis and adequate treatment can be reached and initiated in timely fashion. After surgical treatment, a long-term clinical, laboratory and imaging follow up is necessary.