Intraspinal Component Research Articles

Diagnostic imaging and surgical treatment of dumbbell tumors of the mediastinum

We describe the diagnostic procedures and surgical approaches employed in 5 patients with dumbbell tumors of the mediastinum. Magnetic resonance imaging accurately described the existence and longitudinal extension of the intraspinal component of the tumor and assisted in choosing the appropriate surgical approach. Both the intrathoracic and intraspinal components of the tumor were resected at one time by a thoracic and neurosurgical team. We employed the Grillo technique three times and a separate laminectomy and thoracotomy approach. Magnetic resonance imaging proved the most useful diagnostic technique for suspected dumbbell mediastinal tumors. In our experience, the extended thoracotomy proposed by Grillo and co-workers worked well for small tumors involving only one foramen in which the intraspinal extension was limited to 2 to 3 cm, and when no more than two laminectomies were required. On the other hand, thoracotomy and a longitudinal paravertebral incision are preferable for larger tumors (more than 4 cm) involving more than one foramen in which the intraspinal extension exceeds 2 to 3 cm, for tumors requiring multiple laminectomy, and when bony infiltration is present.

CT and MR Imaging of Mediastinal Hemangiomas

We describe the CT findings in two cases of mediastinal hemangioma. In one, contrast enhanced CT demonstrated peripheral puddles of contrast medium within the mass, similar to the findings seen in cavernous hemangiomas of the liver. In the other case magnetic resonance (MR) was performed; the mass had an intraspinal component and was hypointense on T1-weighted sequences and hyperintense on T2-weighted sequences; imaging features were similar to those of neurogenic tumors. Although they have a nonspecific appearance on MR, these tumors may demonstrate characteristic contrast enhancement features on CT. Hence, hemangiomas of the mediastinum, although rare, should be included in the differential diagnosis of enhancing mediastinal masses.

Combined Approach to “Dumbbell” Intrathoracic and Intraspinal Neurogenic Tumors

The unexpected finding of an extension of a neurogenic tumor from the thorax through the spinal foramen into the neural canal complicates its removal. Serious neurological complications may result from a two-stage approach, whether done first through the thorax or neural canal. Vertebral tomography or computed tomographic scanning reveals enlargement of a spinal foramen in advance of operation. Myelography confirms the probable presence of an intraspinal component. Four patients have been operated on using an approach designed to allow wide posterolateral thoracotomy and concomitant laminectomy for single-stage removal of the entire tumor. In 3 patients the diagnosis was schwannoma and in 1, neurofibroma. All had good results.