Rare mediastinal masses – imaging review

Abstract

Mediastinal masses span a wide histopathological and radiological spectrum. Apart from primary thymic/thyroid masses and lymphomas, all other mediastinal masses can be considered rare tumors. Chest radiography and Computed tomography (CT) are helpful to characterize the mass and can reach a diagnosis or a close differential diagnosis. MRI in special situations can depict the pericardial/vascular invasion better, and diffusion studies can recognize benign from the malignant mass. The imaging details of 15 histopathologically proven cases of rare mediastinal tumors are described. Neuroblastoma (NB) (n = 3) was the most common among the rare masses. Three were sarcomas, one liposarcoma, one synovial sarcoma, one spindle-cell tumor and one Hemangiopericytoma (HPC). Lymphoma presenting as a single mass, neuroendocrine tumor (NET) of the anterior mediastinum, paraganglioma of the posterior mediastinum (one each) were seen.The imaging features of these rare mediastinal masses have to be kept in mind for appropriate diagnosis.

Mediastinal liposarcoma: Case report with radiology review

“…There are many pathologies that can present as a mediastinal mass, some of which are thymic neoplasm, teratoma, lymphoma, neurofibroma, and esophageal cancer. Liposarcomas have nonspecific findings on a radiograph such as abnormal mediastinal contouring and will appear as an inhomogeneous lobulated mass with areas of hypoattenuation representing fat on a CT scan [ 5 ]. This requires the use of MRI to allow for better characterization of liposarcomas considering their heterogeneous architecture through differentiation of lipid/water components, pericardial/vascular invasion, and superior soft tissue visualization [ 5 , 6 ].…”

“…Liposarcomas have nonspecific findings on a radiograph such as abnormal mediastinal contouring and will appear as an inhomogeneous lobulated mass with areas of hypoattenuation representing fat on a CT scan [ 5 ]. This requires the use of MRI to allow for better characterization of liposarcomas considering their heterogeneous architecture through differentiation of lipid/water components, pericardial/vascular invasion, and superior soft tissue visualization [ 5 , 6 ]. Imaging features suggesting liposarcoma over a simple lipoma lesion are lesion size greater than 10 centimeters (cm), presence of thick septa, nodular/globular area, and an associated nonadipoase mass [ 7 ].…”

Thoracoscopic resection of posterior mediastinal paraganglioma: perioperative management and surgical tips

“…In some case reports, the diagnosis was not made until uncontrollable tachycardia, hypertension, and easy hemorrhage occurred during the operation [ 1 , 2 ]. Therefore, it is essential to include PGL as a differential diagnosis for mediastinal tumors [ 1 , 3 ]. Once this tumor is suspected, the path to diagnosis is relatively uncomplicated because its characteristic findings can be obtained by CE-CT, MRI, and 131 I-MIBG scintigraphy [ 4 ].…”

“…CE-CT is useful for diagnosis because PGL generally appears as a highly enhanced tumor. Some reports suggest that MRI is more useful because flow voids of tumor blood vessels are observed in the relatively higher-signal parenchyma of PGLs, demonstrating the characteristic “salt and pepper” appearance on T1-weighted images [ 1 , 3 , 5 ]. In the current case, a few flow voids were observed in the tumor.…”

Retroperitoneal alveolar rhabdomyosarcoma intruding into spinal canal: A case report and literature review

“…PET/CT is superior at revealing lymph nodes and distant organ metastases, which can provide an objective imaging basis for preoperative diagnosis and accurate staging of neuroblastoma in children, over conventional imaging. Calcification could be seen in almost 90% of cases, appearing as sandy, spotted, and mass shapes, which is a characteristic manifestation of neuroblastoma ( 37 ). 123 I-Metaiodobenzylguanidine (MIBG) plays an important role in the diagnosis of neuroblastoma with an accumulation of MIBG in the lesions ( 38 ).…”