Intracranial epidermoid cysts are benign slow-growing ectodermal inclusions that account for less than 1% of all intracranial tumors. We retrospectively reviewed 36 such cases to evaluate the demographic characteristics, clinical manifestations, anatomical distribution, surgical management, and treatment outcome of these tumors. Additionally, we sought to identify the relationship between median or paramedian cistern tumor localization and clinical parameters, such as recurrence risk, hospitalization duration, and postoperative complication rates. The most frequently observed neurological symptoms were transient headaches (77.8%), dizziness (36.1%), CN VII palsy (19.4%), CN VIII hearing difficulty (19.4%) and cerebellar signs (19.4%). The most common surgical approaches included retrosigmoid (36.1%), subfrontal (19.4%) and telovelar (19.4%) approaches; gross total resection was feasible in 83.3% of cases. The postoperative complication rate was 38.9%. Tumors were more frequently found in the paramedian cisterns (47.2%), followed by the median line cisterns (41.6%). Multivariate analysis revealed that postoperative hydrocephalus and age < 40 years were prognostic factors for tumor recurrence. Median-like tumor location was a risk factor for the presence of symptomatic hydrocephalus both preoperatively and postoperatively, increasing the likelihood of protracted hospitalization (> 10 days). Despite their benign histopathological nature, these tumors have an important clinical resonance, with a high rate of postoperative complications and a degree of recurrence amplified by younger age and hydrocephalus.

Background: Tumor-like lesions at the craniovertebral junction mimic tumors in clinical presentation and imaging. Our study focuses on three common developmental pathologies—epidermoids, dermoids and neurenteric cysts. Methods: We conducted a retrospective analysis of a case series and a meta-analysis of 170 patients from 119 reports. Results: Neurenteric cysts predominated (81.2%). Anterior cysts were linked to neurenteric cysts, while posterior ones correlated with dermoid/epidermoid cysts (p < 0.001). Complications occurred in 27.2% of cases, with cranial nerve paresis being the most common. Most patients had excellent outcomes (75.2%) with low recurrence rates (12%). Dermoid cysts were more associated with anomalies (p < 0.001). Among 138 neurenteric cyst cases, 15 experienced recurrence, with predictors including ages 51–60 and over 70, subtotal resection, complications, and poor outcomes (p < 0.001). Cysts with total resection were significantly less likely to adhere to surrounding brain tissue (p < 0.001). CSF diversion was correlated with older age (p = 0.010) and various complications (p < 0.001). Age affected outcomes, and the hydrocephalus was linked to poor outcomes (p = 0.002). Conclusions: This meta-analysis underscores the importance of total resection in minimizing recurrence rates and emphasizes meticulous preoperative planning and imaging. Our results indicate that rim enhancement (p = 0.047) and poor outcome (p = 0.007) are significant factors associated with recurrence. Additionally, associated anomalies, as well as the patient’s age and overall health, significantly influence the surgical outcomes and the likelihood of recurrence.

Objective To present an alternative surgical technique in treating cases of Chiari I Malformation with mild‐to‐moderate syringomyelia after decompressive suboccipital craniectomy: incising only the outer layer of the dura mater, then dissecting it from the inner layer without opening the latter. Patients and methods We utilized this technique in a short series of three cases who were admitted to our department for mild symptoms such as intermittent headache and dissociated sensory loss in the upper limbs, caused by a Chiari Malformation Type I. The patients were placed in the sitting position. We performed a reduced median suboccipital craniectomy and resection of the posterior arch of C1 adapted to the level of tonsil descent, from a limited superior half to complete resection. Afterward, we incised the outer dural layer, while sparing the inner one. Using a fine dissector, we then split apart the outer and inner layers to the margin of the craniectomy. Through the transparency of the inner layer and the arachnoid, the cerebellum and the medulla were visible and pulsating. An autologous fascia duraplasty was then performed. Results The postoperative course was favorable in all cases, the patients being discharged without any deficits and with complete symptom resolution. Follow‐up at 3, 6, and 12 months after surgery revealed a significant reduction in brainstem compression and syringomyelia. Conclusions Interlayer dural split technique can be used effectively in treating symptomatic cases of type I Chiari malformation in adults, with mild‐to‐moderate syringomyelia. It is less invasive than opening the dura and possibly more effective than decompressive craniectomy and C1 laminectomy alone. This technique must be validated in a larger case‐control series.

Background: Congenital intracranial cystic lesions—epidermoid, dermoid, neurenteric, Rathke, colloid—encompass a heterogeneous group of entities whose surgical behavior is only partly explained by histology. We propose a dual-axis cisternal topographic model (medial–lateral × dorsal–ventral) to compare surgical outcome in congenital intracranial cystic lesions. Methods: We retrospectively analyzed 110 patients with histologically confirmed congenital intracranial cysts undergoing surgical resection at a single tertiary center. Each lesion was categorized by cisternal topography in coronal and axial planes, and correlations were assessed between topographic class, surgical parameters, recurrence, and outcomes. Inter-rater reliability of classification was measured using Cohen’s kappa. Results: Lesions with complex cisternal topography—defined as extension across dorsal–ventral (multicompartmental, MCL) or combined median-paramedian compartments—showed higher recurrence (42.1% and 50%, respectively; p < 0.001), including late recurrence beyond five years (23.7% and 35%, respectively; p < 0.001). MCL carried greater surgical morbidity: higher rates of subtotal resection (44.7% vs. 8.3%, p < 0.001), prolonged hospitalization, and doubled complication burden (52.6% vs. 25%, p = 0.006). Functional outcomes were poorer in these subgroups (median GOS = 4, IQR: 4–5), and neurological sequelae, particularly cranial nerve VII/VIII deficits and cerebellar signs, were disproportionately more frequent. A strong correlation emerged between cyst topography and histopathology, epidermoids predominating in complex configurations ( p < 0.001). Supplementary analyses indicated that although cyst size varied across histological subtypes, it was not associated with recurrence, and in multivariable models cisternal localization remained significant, whereas histology and maximum dimension did not. Conclusions: Cisternal topography was associated with recurrence, surgical complexity, and postoperative outcome in congenital cystic lesions. Lesions with multicompartmental or midline-paramedian axial spread carry a high-risk profile and warrant extended surveillance beyond five years. This dual-axis anatomical model may inform more tailored operative strategies and long-term follow-up planning, complementing histological diagnosis in modern skull base surgery.

In this article, we discuss the theory that an error in dural development and/or signaling is responsible for the occurrence of Chiari 1 Malformations (CM1). Other widely accepted theories such as the premature closure of the spheno-occipital synchondrosis, or the paraxial mesodermal defect during embryogenesis are discussed, along with the most relevant evidence to substantiate our hypothesis.