Non-neoplastic bulky mediastinal mass presentation in an adolescent patient: a case report

Abstract

Introduction: Mediastinal masses in pediatric patients are very heterogeneous in origin and etiology. In the first decade of life, 70% of the mediastinal masses are benign whereas malignant tumors are more frequent in the second decade of life. Among the mediastinal masses, lymph nodes are the most common involved structures and could be enlarged due to a lymphoma, leukemia, metastatic disease, or due to infectious diseases as sarcoidosis, tuberculosis and others.

Case presentation: We report a case of a 13-year-old Caucasian girl who came to the emergency room with a history of intermittent fever, weight loss and night sweating for at least 1 month. A radiologic image work-up presented an anterior and posterior mediastinal mass. The 18F-fluorodeoxyglucose positron emission tomography presented a high maximum standard uptake value, which directed our decision for mediastinal biopsy for diagnostic elucidation. Histologic examination described the mass as granulomatous tuberculosis. The patient was treated with anti-tuberculosis therapy and developed a full clinical recovery.

Conclusions: The present case report demonstrates that a bulky mediastinal lymphadenopathy detected on 18F-fluorodeoxyglucose positron emission tomography is not always a malignant lesion, and in countries where tuberculosis is endemic, this etiology should not be forgotten during clinical investigations. There is a need for more accurate cut-off values for this technology; meanwhile, the further investigation of patients with bulky mediastinal masses with procedures such as the open biopsy is indispensable.

Figure 1

(a-c) Axial contrast-enhanced computed tomography image of the mediastinal region, and (b-d) fused transverse ¹⁸ F-fluorodeoxyglucose-positron emission tomography-computed tomography image at the mediastinal region where the arrow is pointed there was an increased ¹⁸ F-fluorodeoxyglucose uptake in the anterior and posterior mediastinum as well as in the left peribronchial nodes.

Figure 2

(a) Anterior view of a maximum intensity projection ¹⁸ F-fluorodeoxyglucose positron emission tomography, (b-c) Sagittal and coronal fused ¹⁸ F-fluorodeoxyglucose-positron emission tomography-computed tomography images of intense hypermetabolism in the anterior and posterior mediastinal masses (arrows).

Figure 3

The image shows lack of the architecture of lymphoid tissue and depletion of lymphocytes which were replaced by large areas of caseous necrosis (a), and granulomatous chronic inflammation accompanied with Langhans-type multinucleate giant cells (b) (photomicrographs obtained from hematoxylin and eosin-stained histologic sections at ×100 and ×200μm).