Melanoma metastases to the CNS rank third in frequency, just after lung and breast metastases. There is controversy regarding the factors predisposing to developing CNS metastases in patients with cutaneous melanoma and their survival with conventional treatments. We carried out a retrospective analysis in a third-level hospital in Mexico to determine epidemiological aspects of melanoma metastases to the central nervous system, factors related to its appearance, clinical presentation, and survival in three treatment groups: surgery, radiotherapy, and conservative management. We found that the nodular variant has the most significant association with CNS metastases. In addition, the superficial spreading variant has the highest risk of presenting a more substantial number of lesions, up to seven for each case and predominantly in the infratentorial space. On the other hand, we found more remarkable survival in patients treated only with surgery than those treated with radiotherapy or conservatively. This study lays the foundations for future prospective survival analysis of the different current treatment modalities for metastatic melanoma in the brain and spine. It also highlights the clinical risk factors for metastatic brain and spine tumors of melanoma.

Background/Objectives: WHO grade II meningiomas show highly variable growth rates that are difficult to predict using conventional histology. We investigated relationships between immune components within the tumor immune microenvironment (TIME) and explored their association with tumor growth kinetics. Methods: We retrospectively evaluated a small, preselected cohort of 15 patients with WHO grade II meningiomas who underwent initial “watch-and-wait” observation with serial preoperative MRI. Notably, this cohort represents a specific clinical subset—tumors deemed initially observable—and may not be representative of all WHO grade II meningiomas. Densities of Iba1-positive macrophages (TAMs) and B7-H3-positive tumor cells were quantified by digital pathology. The relative growth rate (RGR) was calculated from serial MRI. Results: A strong inverse correlation was observed between TAM density and B7-H3-positive tumor cell density (Spearman’s R = −0.921, p < 0.001). Individual immune components did not show significant linear correlations with RGR; on median-split stratification, high B7-H3-positive tumor cell density was associated with a nominally significant difference in RGR (p = 0.0428, unadjusted). Low TAM density showed a non-significant trend in the same direction. Conclusions: Our findings generate the hypothesis that WHO grade II meningiomas exhibit an inverse relationship between TAMs and B7-H3 and that macrophage-poor/B7-H3-high and macrophage-rich/B7-H3-low patterns may differ in preoperative growth behavior. These observations are derived from a small, preselected cohort of tumors managed with an initial “watch-and-wait” strategy and require validation in broader populations.

BACKGROUND: von Hippel-Lindau disease–associated hemangioblastomas (HBs) account for 20%–30% of all HB cases, with the appearance of new lesions often observed in the natural course of the disease. By comparison, the development of new lesions is rare in patients with sporadic HB. OBSERVATIONS: A 65-year-old man underwent clipping for an unruptured aneurysm of the anterior communicating artery. Fourteen years later, follow-up magnetic resonance imaging (MRI) revealed a strongly enhanced mass in the right cerebellar hemisphere, diagnosed as a sporadic HB. A retrospective review of MRI studies obtained over the follow-up period revealed the gradual development of peritumoral edema and vascularization before mass formation. LESSONS: Newly appearing high-intensity T2 lesions in the cerebellum may represent a preliminary stage of tumorigenesis. Careful monitoring of these patients would be indicated, which could provide options for early treatment to improve patient outcomes.

BACKGROUND: Optic pathway gliomas are uncommon, accounting for 3–5% of childhood brain tumors, and are mostly classified as pilocytic astrocytomas (PAs). PAs of the optic nerve are particularly rare in adults. OBSERVATIONS: The authors presented the case of PA of the left optic nerve in a 49-year-old woman along with detailed pathological and molecular analyses and sequential magnetic resonance imaging. The tumor had progressed during 5 years of follow-up along with cyst formation and intracystic hemorrhage; it had a thick capsule and contained xanthochromic fluid. The boundary between tumor and optic nerve was unclear. B-type Raf kinase ( BRAF ) V600E point mutations or translocations, IDH1-R132H mutations, loss of alpha-thalassemia/mental retardation X-linked, and 1p/19q codeletion were negative. LESSONS: BRAF alterations in pediatric PAs of the optic nerve are less frequent than those observed in PAs in other lesions; the same molecular pattern was observed in the adult case, without changes in BRAF . Surgical management should be indicated only in cases with severely impaired vision or disfigurement because there is no clear border between the tumor and optic nerve. Further discussion is needed to optimize the treatment for adult optic pathway gliomas, including radiotherapy, chemotherapy, and molecular-targeted therapies, in addition to surgical intervention.

CD19を標的としたキメラ型抗原受容体（chimeric antigen receptor，CAR）-T細胞療法は血液がん領域において高率な抗腫瘍効果を示し，早くから固形がんへの適応拡大が期待されてきたが，以後目立った成果をあげられずに現在に至っている。固形がんにおける免疫抑制性がん微小環境におけるT細胞疲弊がCAR-T細胞療法を含む免疫療法の有効性を損なう主因の一つであり，そのメカニズム解明が目下の課題である。 本稿ではT細胞受容体（T cell receptor，TCR）-T細胞，CAR-T細胞における既知の疲弊機序に加え，近年明らかとなったCAR-T細胞のNK様疲弊について述べ，それらの知見に基づく疲弊化克服への戦略について概説する。

BACKGROUND: Moyamoya disease (MMD) is a progressive cerebrovascular disorder characterized by stenosis of the distal internal carotid arteries and development of collateral vessels. While surgical revascularization through direct superficial temporal artery–to–middle cerebral artery (MCA) bypass is the primary treatment for adults with MMD, rare but potentially fatal hemorrhagic complications can occur due to hemodynamic changes. OBSERVATIONS: A 34-year-old male with MMD who had previously undergone combined direct and indirect bypass surgery developed a massive intracerebral hemorrhage 2.5 months postoperatively. Imaging revealed an aneurysm at the anastomosis site as the bleeding source. Emergency surgery was performed to evacuate the hematoma and clip the aneurysm while preserving the bypass. The aneurysm originated from the MCA wall opposite to the anastomotic site, suggesting a hemodynamic etiology. Postoperative angiography confirmed complete clipping with preserved anastomotic patency. The patient was discharged with severe left-sided hemiparesis but without speech or cognitive impairment. LESSONS: This case represents the shortest documented interval between combined bypass surgery and a ruptured de novo anastomotic aneurysm. Genetic predisposition, inflammatory processes, and hemodynamic alterations likely contribute to aneurysm formation. Standardized postoperative surveillance and individualized management strategies are essential to mitigate these risks. https://thejns.org/doi/10.3171/CASE25429