Primary Anaplastic-Lymphoma-Kinase-Positive Large-Cell Lymphoma of the Central Nervous System: Comprehensive Review of the Literature

BACKGROUND

Primary anaplastic-lymphoma-kinase (ALK)-positive large-cell lymphoma of the central nervous system (PCNS ALK-positive ALCL) is a rare entity, with a limited consensus reached regarding its management. While this pathology often presents as solitary lesions, the occurrence of multiple tumors within the brain is not uncommon. The lack of distinctive radiological features poses a diagnostic challenge, leading to delays in initiating targeted therapy.

METHODS

We conducted a comprehensive literature search, identifying seventeen publications for qualitative analysis.

RESULTS

The management options and reported patient outcomes in the literature varied significantly, emphasizing the need for a patient-specific approach. The emergence of ALK-specific inhibitors represents a new frontier in this field, demonstrating promising results.

CONCLUSION

PCNS ALK-positive ALCL necessitates a comprehensive understanding and optimized management strategies. A tailored therapeutic approach, integrating surgical intervention with radiotherapy and chemotherapy, appears pivotal in addressing this pathology. The implementation of a therapeutic protocol is anticipated for further advancement in this field.

Endoscopic Endonasal Transclival Approach to the Ventral Brainstem: Anatomic Study of the Safe Entry Zones Combining Fiber Dissection Technique with 7 Tesla Magnetic Resonance Guided Neuronavigation

BACKGROUND

Treatment of intrinsic lesions of the ventral brainstem is a surgical challenge that requires complex skull base antero- and posterolateral approaches. More recently, endoscopic endonasal transclival approach (EETA) has been reported in the treatment of selected ventral brainstem lesions.

OBJECTIVE

In this study we explored the endoscopic ventral brainstem anatomy with the aim to describe the degree of exposure of the ventral safe entry zones. In addition, we used a newly developed method combining traditional white matter dissection with high-resolution 7T magnetic resonance imaging (MRI) of the same specimen coregistered using a neuronavigation system.

METHODS

Eight fresh-frozen latex-injected cadaver heads underwent EETA. Additional 8 formalin-fixed brainstems were dissected using Klingler technique guided by ultra-high resolution MRI.

RESULTS

The EETA allows a wide exposure of different safe entry zones located on the ventral brainstem: the exposure of perioculomotor zone requires pituitary transposition and can be hindered by superior cerebellar artery. The peritrigeminal zone was barely visible and its exposure required an extradural anterior petrosectomy. The anterolateral sulcus of the medulla was visible in most of specimens, although its close relationship with the corticospinal tract makes it suboptimal as an entry point for intrinsic lesions. In all cases, the use of 7T-MRI allowed the identification of tiny fiber bundles, improving the quality of the dissection.

CONCLUSION

Exposure of the ventral brainstem with EETA requires mastering surgical maneuvers, including pituitary transposition and extradural petrosectomy. The correlation of fiber dissection with 7T-MRI neuronavigation significantly improves the understanding of the brainstem anatomy.

Endoscopic endonasal control of the paraclival internal carotid artery by Fogarty balloon catheter inflation: an anatomical study

OBJECTIVE Neurosurgical management of many vascular and neoplastic lesions necessitates control of the internal carotid artery (ICA). The aim of this study was to investigate the feasibility of achieving control of the ICA through the endoscopic endonasal approach by temporary occlusion with a Fogarty balloon catheter. METHODS Ten endoscopic endonasal paraseptal approaches were performed on cadaveric specimens. A Fogarty balloon catheter was inserted through a sellar bony opening and pushed laterally and posteriorly extraarterially along the paraclival carotid artery. The balloon was then inflated, thus achieving temporary occlusion of the vessel. The position of the catheter was confirmed with CT scans, and occlusion of the ICA was demonstrated with angiography. The technique was performed in 2 surgical cases of pituitary macroadenoma with cavernous sinus invasion. RESULTS Positioning the Fogarty balloon catheter at the level of the paraclival ICA was achieved in all cadaveric dissections and surgical cases through a minimally invasive, quick, and safe approach. Inflation of the Fogarty balloon caused interruption of blood flow in 100% of cases. CONCLUSIONS Temporary occlusion of the paraclival ICA performed through the endoscopic endonasal route with the aid of a Fogarty balloon catheter may be another maneuver for dealing with intraoperative ICA control. Further clinical studies are required to prove the efficacy of this method.

Pedicled lateral nasal wall flap for the reconstruction of the nasal septum perforation. A radio-anatomical study

INTRODUCTION

The aim of this radio-anatomical study is to ensure that the potential donor area of the pedicled lateral nasal wall flap (PLNW) is adequate to reconstruct nasal perforation.

MATERIAL AND METHODS

Analysis was conducted on 40 de-identified CT angiographies. The area and length of the PLNW, the septum, and the nasal floor were measured. In a cadaver study, 20 hemi-cranial sagittal sections were also analyzed. The anterior-posterior length of the PLNW flap and the distance between the sphenopalatine foramen and piriform aperture were measured. A clinical study with endoscopic closure of a large perforation was conducted in three patients.

RESULTS

The CT angiographies demonstrated an average PLNW area of 10.80±1.13 cm2 and a nasal floor area of 3.78±0.58 cm2. The septal area (22.54±21.32 cm2) was significantly larger than the total PLNW flap area (14.59±1.21 cm2). The average length of the flap was 5.58±0.39 cm, while the septum was 6.66±0.42 cm; therefore the PLNW flap is insufficient to reconstruct the entire septum. The cadaver study showed that the length of the PLNW flap was 5.28±0.40 cm. These results demonstrate that measurements obtained from CT scans are reliable data and similar to those found in the radiological study. Complete closure was achieved in all three patients.

CONCLUSION

The PLNW flap does not render enough tissue to reconstruct a total septal perforation; however, up to 84% of the septum could be repaired with a PLNW. The potential donor area obtained by CT scan and clinical practice support the approachability of PLNW to repair large septal perforation.

The extended endoscopic endonasal transplanum transtuberculum approach to the anterior communicating artery complex: anatomic study

BACKGROUND

When performing a transplanum transtuberculum approach, dealing with the anterior communicating artery (ACoA) complex is inevitable. The aim of this study is to provide quantitative anatomical information regarding the ACoA complex and its bony and neural relationships, when exposed through this approach.

METHOD

The endoscopic endonasal transplanum transtuberculum approach was performed on ten human cadaver heads. In each specimen, radiological studies were performed. A three-dimensional model of the approach was reconstructed. Measured parameters were: exposure of the vessels; distance between the proximal anterior cerebral artery (A1) and the optic chiasm; dimension of the bone opening. The feasibility to perform clip placement was graded as "possible" or "not possible".

RESULTS

Dimension of bone opening varied from 88 to 53 mm(2). The ACoA was exposed for 3 mm ± 2 mm, A1 for 17 mm ± 9 mm, the distal anterior cerebral artery (A2) for 12 mm ± 3 mm, the recurrent artery of Heubner (RAH) for 16 mm ± 4 mm. Clip placement was possible on the ACoA, A2, and distal segment of A1 in all cases, and on the proximal segment of A1 in one instance. The distance between A1 and the optic chiasm measured 9 mm ± 2 mm.

CONCLUSIONS

The ACoA, A2, and the distal segment of A1 can be visualized and controlled through the transplanum transtuberculum approach. The relationship between A1, gyrus rectus, and optic chiasm is the main determinant for the exposure and control of the vessel. The olfactory nerve can represent a surgical landmark for the identification of the A1 origin. The whole course of the RAH can be visualized trough this approach.