Malignant transformation of clival chordoma after gamma knife surgery - case report -

Recurrence of Ventral Skull Base Lesions Attributed to Tumor Seeding: A Systematic Review

OBJECTIVE

To evaluate ventral skull base lesion recurrences along surgical access pathways attributed to iatrogenic seeding.

METHODS

A systematic review of the literature was performed searching for recurrence of ventral skull base lesions attributed to iatrogenic implantation. Studies were assessed for level of evidence. Primary intervention, pathology, and other clinical factors were reported following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

RESULTS

Among 69 patients with recurrent skull base lesions attributed to seeding, the most common pathologies were craniopharyngioma (52.2%), chordoma (33.3%), adenocarcinoma (4.3%), adenoid cystic carcinoma (2.9%), and squamous cell carcinoma (2.9%). Median time to recurrence was 36 months. Time to recurrence was significantly longer for craniopharyngiomas than for chordomas (42 months vs. 24 months, P ≤ 0.05). Surgical approaches included craniotomy (62.0%), transseptal (11.3%), transfacial (12.7%), and transpalatal (4.2%). Mean time to recurrence after craniotomy was 69 months. Endoscopic/endoscopic-assisted approaches were used in 5 cases (7.0%). Commonly reported recurrence sites included subarachnoid (29.6%), dura (21.1%), incision (12.7%), septum (7.0%), and ethmoid sinuses (4.2%).

CONCLUSIONS

The potential for iatrogenic tumor seeding exists for numerous skull base lesions, most notably craniopharyngioma and chordomas. Routine surveillance may be necessary owing to significant latency intervals to ectopic recurrence. Although transnasal endoscopic techniques have been extensively employed in recent decades, only a handful of reported cases involve lesions originally treated with this approach. Further direct comparison of traditional approaches with endoscopic approaches may be invaluable in further elucidating the role of surgical technique in tumor implantation and recurrence.

Simultaneous discovery of cranial and spinal intradural chordomas: case report

The present case illustrates the unexpected occurrence of intradural chordomas that were simultaneously discovered in cranial and spinal locations. A 63-year-old female presented with weakness in the left upper extremity. The patient visited a local doctor and underwent brain computerized tomography (CT). CT revealed a brain tumor, and she was referred to our hospital. Brain magnetic resonance imaging (MRI) demonstrated a midline intradural retroclival tumor in addition to an intradural extramedullary mass lesion at the level of C1-C2. The patient developed a spastic gait disturbance that forced her to use a cane. She underwent laminectomy at C1-C2 along with total removal of the tumor and showed no remarkable symptoms after surgery. Histopathological examination confirmed the diagnosis of chordoma. One month after the cervical surgery, the intracranial tumor was subtotally removed in intracranial surgery via the right subtemporal approach. Histopathological data were identical to that of the cervical tumor. The patient consulted another hospital and underwent gamma-knife surgery. Her neurological examination is relatively unchanged 20 months after the cervical surgery. This case suggests that neuroradiological evaluation should also be performed for an intradural spinal chordoma when an intracranial chordoma is detected. Careful determination of the tumor responsible for the symptoms is necessary if an intradural spinal chordoma is simultaneously detected with an intracranial chordoma.

Complications of gamma knife neurosurgery and their appropriate management

There are four main risks with Gamma Knife neurosurgery. Firstly, there are direct complications that would not have arisen if the patient had not undergone the specific treatment under consideration. For radiosurgery, the direct complications are radiation-induced damage to the tissues, which may be temporary or permanent. They may be expressed clinically or be clinically silent. In addition, there are complications that are specific to certain diseases and their locations, such as pituitary failure following treatment of pituitary adenomas and deafness, facial palsy, or trigeminal deficit following the treatment of vestibular schwannomas. Second, there are indirect or management-related complications arising from delayed control of the disease process, such as a re-bleed after treatment of a vascular lesion before its occlusion. Third, there is the risk of induction of neoplasia from irradiation of normal tissue or tumor. These are separate processes. An example of the first would be induction of a glioma after treatment of a vascular malformation. An example of the second would be induction of malignant change in a benign vestibular schwannoma. Finally, there is treatment failure, where tumors continue to grow after treatment or vascular malformations fail to occlude.

Different imaging techniques in the head and neck: Assets and drawbacks

In this review, the gold standard imaging techniques for the head and neck and the latest upcoming techniques are presented, by comparing computed tomography (CT), magnetic resonance imaging and positron emission tomography-CT, as well as ultrasound, depending on the examined area. The advantages and disadvantages of each examination protocol are presented. This article illustrates the connection between the imaging technique and the examined area. Therefore, the head and neck area is divided into different sections such as bony structures, nervous system, mucous membranes and squamous epithelium, glandular tissue, and lymphatic tissue and vessels. Finally, the latest techniques in the field of head and neck imaging such as multidetector CT, dual-energy CT, flash CT, magnetic resonance angiography, spectroscopy, and diffusion tensor tractography using 3 tesla magnetic resonance are discussed.

[CT and MRI of intrinsic space-occupying lesions of the bony skull base]

Intrinsic bony lesions of the skull base are diseases which arise within the bones forming the skull base. Mainly they are bone tumours and tumour-like lesions. With the exception of osteomas of the paranasal sinuses and exostoses of the external auditory canal, these lesions occur rarely. This article gives an overview of the appearance of the most common primary bony skull base masses in CT and MRI. From the authors' point of view these are fibrous dysplasia, chordomas, chondrosarcomas, Langerhans cell histiocytosis and multiple myelomas, which must be differentiated from pseudolesions. The possibilities of CT and MRI in making a specific diagnosis, differential diagnosis and the kind of making the final diagnosis are described.