What Tactics Should a Surgeon Choose to Treat a Black Extracerebral Tumor? A Case Report of Psammomatous Melanotic Schwannoma of the Meckel Cave and Literature Review.

BACKGROUND: Neoplasms located in the Meckel cave account for 0.2%-0.5% of all intracranial tumors. This area is the site of many types of pathologic lesions, most often trigeminal nerve schwannomas and meningiomas. Melanin-containing tumors are rare in this area. These tumor types can be suspected if the magnetic resonance characteristics of a tumor has some differences in comparison with other types of central nervous system neoplasms. In fact, differential diagnosis of melanotic tumors is based mainly on the histopathologic criteria and immunohistochemical profile. This article presents a case report of melanotic schwannoma of the Meckel cave and a literature review of the problem. CASE DESCRIPTION: A 23-year-old man underwent a 2-stage surgery for a dumbbell pigmented mass lesion located in the Meckel cave. No signs of recurrence were seen on follow-up magnetic resonance imaging (MRI) 3.5 years after the operation. CONCLUSIONS: Melanin-containing tumor can be suspected in the presence of radiologic characteristics, such as a hyperintense MRI signal on T1-weighted images and a hypointense signal on T2-weighted images. If a black extracerebral tumor is detected, the main course of surgical treatment is maximal excision despite it possibly being a malignant melanoma and the temptation to perform partial resection because of an unfavorable prognosis. Chemotherapy can be justified in the presence of an aggressive melanotic schwannoma.

Deep Brain Stimulation of the Subthalamic Nucleus in Patients with Parkinson Disease with Prior Pallidotomy or Thalamotomy.

Objective. To evaluate the efficacy of deep brain stimulation of the subthalamic nucleus (STN DBS) in patients with Parkinson disease (PD) who previously underwent lesioning of the basal ganglia. Material and methods. The study included 22 patients who underwent STN DBS. Eleven patients had undergone prior unilateral pallidotomy (n = 6) or VL/VIM thalamotomy (n = 5) while the other 11 patients had not. The primary outcome was the change from baseline in the motor subscore of the Unified Parkinson Disease Rating Scale (UPDRS-III) 12 months after STN DBS. Secondary outcomes included change in motor response complications (UPDRS-IV) and change in levodopa equivalent daily dose (LEDD). Results. In the group with prior lesioning UPDRS-III improved by 45%, from 51.5 ± 9.0% (range, 35–65) to 26.5 ± 8.4 (range, 21–50) (p < 0.01) and UPDRS-IV by 75%, from 8.0 ± 2.01 (range, 5–11) to 2.1 ± 0.74 (range, 1–3) (p < 0.01). In the group without prior lesioning UPDRS-III improved by 61%, from 74.2% ± 7.32 (range, 63–82) to 29.3 ± 5.99 (range, 20–42) (p < 0.01) and UPDRS-IV by 77%, from 9.1 ± 2.46 (range, 5–12) to 2.0 ± 1.1 (range, 1–4) (p < 0.01). Comparing the two groups (with and without lesioning) no significant differences were found either in UPDRS-III (p > 0.05) or UPDRS-IV scores (p > 0.05) at 12 months post-DBS. The LEDD was reduced by 51.4%, from 1008.2 ± 346.4 to 490.0 ± 194.3 in those with prior surgery (p < 0.01) and by 55.0%, from 963.4 ± 96.2 to 433.3 ± 160.2 in those without (p < 0.01).UPDRS-III improved by 51.8%, from 53.7 ± 4.6 (range, 50–62) to 25.0 ± 3.8 (range, 21–31) in those with prior pallidotomy (p < 0.01), and by 37.5%, from 48.8 ± 12.6 (range, 35–65) to 29.8 ± 13.6 (range, 22–50) in those with prior thalamotomy (p < 0.01). This numerical difference in improvement was not statistically significant (p > 0.05). Conclusion. Our comparative study indicates that bilateral STN DBS is effective and can be used in patients with Parkinson disease with prior unilateral stereotactic destructive operations on subcortical structures. The results in our patient cohort are generally consistent with previously published reports of smaller series from multiple centers worldwide.