Blue Lagoon Algae Improve Uneven Skin Pigmentation: Results from in vitro Studies and from a Monocentric, Randomized, Double-Blind, Vehicle-Controlled, Split-Face Study.

INTRODUCTION: Bathing in the Blue Lagoon (BL) in Iceland benefits patients with psoriasis. Accordingly, the BL water contains algae with biological activities that improve skin barrier function and affect T-cell responses relevant for psoriasis. Bathing in the BL is also becoming increasingly popular among healthy individuals and anecdotal evidence suggests positive effects on uneven skin pigmentation. OBJECTIVE: The aim of the study was to address the impact of BL algae on skin pigmentation. METHODS: In this work, in vitro gene expression studies in melanocytes and a noninvasive in vivo study were conducted. RESULTS: We here report that normal human epidermal melanocytes, which had been treated with nontoxic concentrations of BL algae, show a significantly reduced expression of α melanocyte-stimulating hormone-induced expression of genes important for melanin synthesis, such as tyrosinase, tyrosinase-related protein 1, dopachrome tautomerase, melan A protein, and pre-melanosome protein. This in vitro observation prompted us to conduct a randomized, double-blind, intra-individual, comparative split-face in vivo study, in which 60 volunteers with pre-existing facial pigment spots were treated twice daily with a BL algae containing serum or a vehicle control. We found that constitutive skin pigmentation as determined by colorimetry (individual typology angle and luminescence) did not differ significantly between vehicle- and serum-treated skin sites. In marked contrast, digital photography under cross-polarized lighting and RBX technology (VISIA CR) revealed that the number of pigment spots in the serum-treated face decreased significantly compared to the vehicle-treated side. CONCLUSION: Thus, BL algae can affect human melanocyte function in vitro and reduce uneven facial skin pigmentation in vivo.

Fronto-orbito-zygomatic (FOZ) approach for infratemporal fossa lesions extending to middle cranial fossa: our experience and review of literature.

AIM OF THE STUDY: Tumours of the infratemporal fossa (ITF) are rare and include primary tumours, contiguity lesions and metastases. Surgical resection is the gold standard. The fronto-orbito-zygomatic (FOZ) approach is commonly used in order to obtain safe access to the lateral skull base and ITF to resect intra- and extra-cranial tumours. We here describe our series of ITF lesions extending to the middle cranial fossa and/or orbit, treated by single- or two piece FOZ. MATERIAL AND METHODS: All cases of single- or two-piece FOZ approach for an infratemporal fossa lesion extending to the middle cranial fossa operated at our Institution from January 2014 to January 2018 were retrospectively reviewed. The follow-up was for a minimum of four months and a maximum of 60 months. The inclusion criteria were lesions involving the ITF with an extension to the middle cranial fossa and/or orbit. Baseline characteristics of patients, tumour localisation, tumour extension, diffusion route, histology, extent of tumour resection, postoperative treatment, and post-operative complications were evaluated. RESULTS: Nine patients underwent a surgical procedure with a FOZ approach, two of them with a single-piece approach and the remainder with a two-piece one. All patients had an ITF localisation. Gross total removal (GTR) was achieved in 7/9 patients. Only one patient, with non-total removal (NTR), underwent radiotherapy. CONCLUSIONS: For the treatment of ITF fossa tumours extending to the orbit and or middle cranial fossa, we believe that both FOZ techniques are effective and allow a good medial extension toward the cavernous sinus and parasellar region. But a two-piece craniotomy may ensure a more medial extension and a wider angle of work compared to a one-piece craniotomy.

Orally administered mixed carotenoids protect human skin against ultraviolet A-induced skin pigmentation: A double-blind, placebo-controlled, randomized clinical trial.

BACKGROUND: Photoprotection of human skin is determined as the capacity of sunscreens to prevent ultraviolet (UV) B radiation-induced erythema and UVA radiation-induced pigmentation. It is unequivocal that, in addition to sunscreens, oral supplementation with carotenoids can protect human skin against UVB radiation-induced erythema. It is not known if this is also the case for UVA radiation-induced pigmentation. OBJECTIVE: To clinically evaluate the photoprotective effects of daily supplementation with carotenoids against UVA radiation-induced pigmentation. METHODS: In this double-blind, placebo-controlled trial, 60 subjects (Fitzpatrick types II-IV) were randomized to receive Nutrilite™ Multi Carotene supplement or placebo for 12 weeks. UVB-induced minimal erythemal dose (MED), UVA-induced minimal persistent pigmentation dose (MPPD) and skin carotenoid levels were measured at baseline, 4, 8, and 12 weeks of intervention. Skin color was evaluated by expert clinical graders and by colorimetry. Carotenoid levels in the skin were measured by the Biozoom® device. RESULTS: In the intervention group, a significant increase in comparison with the placebo group was observed in (a) skin carotenoid levels, (b) UVB-induced MED, and (c) UVA-induced MPPD values obtained by colorimetry. CONCLUSION: Daily supplementation with carotenoids protects human skin against both UVB-induced erythema and UVA-induced pigmentation.

Autologous Cell Therapy for Aged Human Skin: A Randomized, Placebo-Controlled, Phase-I Study.

INTRODUCTION: Skin ageing involves senescent fibroblast accumulation, disturbance in extracellular matrix (ECM) homeostasis, and decreased collagen synthesis. OBJECTIVE: to assess a cell therapy product for aged skin (RCS-01; verum) consisting of ~25 × 106 cultured, autologous cells derived from anagen hair follicle non-bulbar dermal sheath (NBDS). METHODS: For each subject in the verum group, 4 areas of buttock skin were injected intradermally 1 or 3 times at monthly intervals with RCS-01, cryomedium, or needle penetration without injection; in the placebo group RCS-01 was replaced by cryomedium. The primary endpoint was assessment of local adverse event profiles. As secondary endpoints, expression of genes related to ECM homeostasis was assessed in biopsies from randomly selected volunteers in the RCS-01 group taken 4 weeks after the last injection. -Results: Injections were well tolerated with no severe adverse events reported 1 year after the first injection. When compared with placebo-treated skin, a single treatment with RCS-01 resulted in a significant upregulation of TGFß1, CTGF, COL1A1, COL1A2, COL3A1, and lumican mRNA expression. LIMITATIONS: The cohort size was insufficient for dose -ranging evaluation and subgroup analyses of efficacy. CONCLUSIONS: RCS-01 therapy is well tolerated and associated with a gene expression response consistent with an improvement of ECM homeostasis.

Tomato Phytonutrients Balance UV Response: Results from a Double-Blind, Randomized, Placebo-Controlled Study.

BACKGROUND: Our previous double-blinded, placebo-controlled cross-over study indicated that a nutritional supplement named lycopene-rich tomato nutrient complex (TNC) can protect from UVA1-induced (340-400 nm) and UVA- (320-400 nm)/UVB-induced (280-320 nm) upregulation of molecular markers associated with oxidative stress, inflammation, and ageing. OBJECTIVES: in the current double-blind, randomized, placebo-controlled multicenter study, we analyze whether a similar, synergistic carotenoid-rich TNC can protect from broadband UVB-induced threshold erythema formation assessed as increase in minimal erythemal dose (MED) reading, the intensity of erythema formation, and the upregulation of molecular markers associated with inflammation and immunosuppression, and whether this correlates with carotenoid blood levels. METHODS: One hundred and forty-nine healthy volunteers were randomized to two groups and subjected to a 5-week washout phase, followed by a 12-week treatment phase receiving either 15 mg lycopene, 5.8 mg phytoene and phytofluene, 0.8 mg ß-carotene, 5.6 mg tocopherols from tomato extract, and 4 mg carnosic acid from rosemary extract per day or placebo made from medium-chain triglycerides. At the end of each phase, MED determination, UVB irradiation, chromametry, biopsies, and blood samples were undertaken. RESULTS: The active supplement was well tolerated. Interestingly, no significant difference was seen in the MED between the active-supplement and placebo groups, as determined by visual grading by expert assessors. Of note, the carotenoid-containing supplement significantly protected against UVB-induced erythema formation measured as Δa* after the intervention minus Δa* after the washout phase as compared to the placebo. Moreover, intake of the active supplement significantly protected against UVB-induced upregulation of IL6 and TNFα as compared with the intake of placebo. Lastly, carotenoid plasma levels were significantly increased. CONCLUSION: This well-tolerated carotenoid-containing supplement significantly protected against UVB-induced erythema formation and upregulation of proinflammatory cytokines in healthy volunteers.

French Maritime Pine Bark Extract (Pycnogenol®) Effects on Human Skin: Clinical and Molecular Evidence.

Nutritional strategies to benefit skin health are of growing importance. Current approaches mainly involve nutritional supplements containing antioxidants which were initially designed to protect human skin against ultraviolet radiation-induced damage. Within recent years, however, a growing number of studies suggests that the beneficial effects of these products clearly extend beyond photoprotection. In this review we take the nutritional supplement Pycnogenol®, which is based on an extract prepared from French marine pine bark extract, as an example to illustrate this development. Accordingly, the existing data provide compelling evidence that Pycnogenol® intake does not only provide photoprotection, but may be used to (i) reduce hyperpigmentation of human skin and (ii) improve skin barrier function and extracellular matrix homeostasis.

Photoprotection of human skin beyond ultraviolet radiation.

Photoprotection of human skin by means of sunscreens or daily skin-care products is traditionally centered around the prevention of acute (e.g. sunburn) and chronic (e.g. skin cancer and photoaging) skin damage that may result from exposure to ultraviolet rays (UVB and UVA). Within the last decade, however, it has been appreciated that wavelengths beyond the ultraviolet spectrum, in particular visible light and infrared radiation, contribute to skin damage in general and photoaging of human skin in particular. As a consequence, attempts have been made to develop skin care/sunscreen products that not only protect against UVB or UVA radiation but provide photoprotection against visible light and infrared radiation as well. In this article, we will briefly review the current knowledge about the mechanisms responsible for visible light/infrared radiation-induced skin damage and then, based on this information, discuss strategies that have been successfully used or may be employed in the future to achieve photoprotection of human skin beyond ultraviolet radiation. In this regard we will particularly focus on the use of topical antioxidants and the challenges that result from the task of showing their efficacy.

Prevention of polymorphic light eruption by oral administration of a nutritional supplement containing lycopene, ß-carotene, and Lactobacillus johnsonii: results from a randomized, placebo-controlled, double-blinded study.

BACKGROUND: Polymorphic light eruption (PLE) is the most common photodermatosis. Little is known about the efficacy of systemic photoprotection provided by nutritional supplements in PLE patients. PURPOSE: The purpose of this study was to assess efficacy of nutritional supplement containing lycopene, ß-carotene, and Lactobacillus johnsonii to diminish skin lesions induced by 'photoprovocation' testing in PLE patients. METHODS: In this randomized, placebo-controlled, double-blinded study, 60 PLE patients were supplemented with the nutritional supplement or placebo. For inducing skin lesions, patient skin was exposed to single daily doses of 100 J/cm2 ultraviolet A1 (UVA1) for two consecutive days. Skin lesions were evaluated using a PLE score. Skin biopsies were taken before and after supplementation from unexposed and exposed skin, and intercellular adhesion molecule 1 (ICAM-1) mRNA expression was assessed by real-time polymerase chain reaction. RESULTS: Prior to supplementation, skin lesions were induced in all patients with comparable PLE scores. After 12 weeks, intake of the supplement significantly reduced the PLE score after one exposure as compared with patients taking placebo (P<0.001). After two exposures, these differences were no longer significant. At a molecular level, the development of skin lesions was associated with an increased expression of ICAM-1 mRNA, which was significantly reduced after supplementation (P=0.022), but not with placebo. CONCLUSION: The nutritional supplement provides protection against the development of UVA-induced PLE lesions at clinical and molecular levels.

Eagle syndrome: An updated review.

Background: This work aims to review the current literature and our experience on vascular Eagle syndrome (ES) that can present misleading clinical presentations and better understand the possible therapeutic strategies. Methods: We reviewed the existing literature on PubMed from January 1, 2017, to December 31, 2022, including the sequential keywords "vascular AND Eagle syndrome," "vascular AND styloid syndrome," "vascular AND elongated styloid process," "vascular AND stylocarotid syndrome," and "Eagle syndrome AND carotid artery dissection." Results: 38 vascular ES cases, including our experience, were analyzed. The most frequent clinical onset was hemiparesis (n 21, 57%), but other regular clinical presentations were aphasia, loss of consciousness, amaurosis, headache, or a combination of the latter. Massive oral bleeding was reported only once in the literature before our case. Twelve patients were treated with only antiplatelet therapy, either single or double. Nine patients were treated with anticoagulation therapy only. In 14 patients, a carotid artery stent was used, associated with anticoagulation or antiplatelet therapy. In 17 cases, a styloid process (SP) resection was performed. Conclusion: ES has many clinical presentations, and carotid artery dissection resulting in oral bleeding seems rare. Literature results and our experience make us believe that when dealing with vascular ES, the best treatment strategy is endovascular internal carotid artery stenting with antiplatelet therapy, followed by surgical removal of the elongated SP to prevent stent fracture.

Modulation of skin pigmentation by the tetrapeptide PKEK: in vitro and in vivo evidence for skin whitening effects.

Uneven skin pigmentation is a significant cosmetic concern, and the identification of topically applicable molecules to address this issue is of general interest. We report that the tetrapeptide PKEK (Pro-Lys-Glu-Lys) can exert skin whitening effects based on one in vitro and four double-blinded vehicle-controlled in vivo studies. (i) Treatment of human keratinocytes with PKEK significantly reduced UVB-stimulated mRNA expression of interleukin (IL)-6, IL-8 and TNF-α and, most importantly, proopiomelanocorticotropin (POMC), i.e. a gene encoding the pigmentation-inducing soluble mediator α- (α-MSH). (ii) PKEK treatment significantly inhibited UVB-induced upregulation of genes encoding for IL-1α, IL-6, IL-8, TNF-α as well as POMC and tyrosinase in 10 healthy volunteers pretreated with PKEK for 4 weeks once daily. (iii) In a study enrolling 39 Caucasian women, facial pigment spots significantly faded after 6 weeks when PKEK was combined with the skin whitener sodium ascorbyl phosphate (SAP), whereas PKEK or SAP alone led to less pronounced fading of the pigment spots. (iv) Addition of PKEK enhanced the skin whitening potency of a SAP-containing preparation if applied for 8 weeks to the back of hands of 19 Caucasians. (v) 27 Japanese women were treated on their faces twice daily with an SAP only or a PKEK+SAP-containing formulation for 8 weeks. Application of PKEK+SAP significantly reduced skin pigmentation by 26% and by 18% according to SCINEXA score. We demonstrate that PKEK has the capacity to reduce UVB-induced skin pigmentation and may be suited to serve as a skin tone-modulating agent in cosmetic products.

Herophilus-Galen line as a predictor of extent of resection in the occipital interhemispheric transtentorial approach to pineal tumors in children.

OBJECTIVE: The goals of this study were to evaluate the extent of resection (EOR) obtained with an occipital interhemispheric transtentorial approach (OITA) in a series of pediatric patients with pineal region tumors and to define preoperative radiological factors predictive of the EOR. METHODS: This is a retrospective cohort study of a series of pediatric patients with pineal tumors who underwent surgery through a microsurgical OITA performed by the senior author during the period from January 2006 to January 2020. The tumor volume was measured preoperatively, and then on sagittal midline cuts the authors identified the most cranial point of the torcular Herophili (defined as the "Herophilus point") and the lowest point of the inferior profile of the vein of Galen (defined as the "Galen point"). The line joining these two points (defined as the "Herophilus-Galen line" [H-G line]) was used to identify the "Herophilus-Galen plane" (H-G plane) perpendicular to the sagittal plane. Tumor volumes located below and above this plane were measured. EOR was evaluated by measuring residual tumor volume visible on T1 volumetric injected sequences of immediate postoperative MRI. RESULTS: Thirty patients were selected for study inclusion. The preoperative mean tumor volume was 15.120 cm3 (range 0.129-104.3 cm3). The mean volumes were 2.717 cm3 (range 0-31 cm3) above the H-G plane and 12.40 cm3 (median 5.27 cm3, range 0.12-72.87 cm3) below the H-G plane. Three patients underwent only biopsy. Of the remaining 27 patients, gross-total resection (GTR; 100% tumor volume) was achieved in 20 patients (74%). In the remaining 7 patients, the mean residual tumor volume was 7.3 cm3 (range 0.26-17.88 cm3). In 3 of these patients, GTR was accomplished after further surgical procedures (1 in 2 patients, 3 in 1 patient) for an overall GTR rate of 85.18%. Larger tumor volume was significantly associated with incomplete resection (p < 0.001). A tumor volume ≤ 2 cm3 above the H-G plane (p = 0.003), linear extension ≤ 1 mm above the H-G line, and pineal histology were predictive of GTR at first OITA procedure (p = 0.001). CONCLUSIONS: The H-G line is an intuitive, easy-to-use, and reliable indicator of the superior anatomical limit of visibility during the microsurgical OITA. This anatomical landmark may be useful as a predictor of EOR for pineal tumors performed through this approach. The main limitations of this study are the small number of patients and the exclusively pediatric age of the patient population.

Clinical Outcome of Patients Over 90 Years of Age Treated for Chronic Subdural Hematoma.

OBJECTIVE: Chronic subdural hematoma (CSDH) is one of the most common pathology in daily neurosurgical practice and incidence increases with age. The aim of this study was to evaluate the prognostic factors and surgical outcome of CSDH in patients aging over 90 years compared with a control group of patients aging under 90 years. METHODS: This study reviewed 25 patients with CSDH aged over 90 years of age treated in our department. This group was compared with a younger group of 25 patients aged below their eighties. At admission past medical history was recorded concerning comorbidities (hypertension, dementia, ictus cerebri, diabetes, and heart failure or attack). History of alcohol abuse, anticoagulant and antiplatelet therapy, head trauma and seizures were analyzed. Standard neurological examination and Markwalder score at admission, 48 hours after surgery and 1-6 months follow-up, radiologic data including location and CSDH maximum thickness were also evaluated. RESULTS: Their mean age was 92.8 years and the median was 92.4 years (range, 90-100 years). In older group, the Markwalder evaluation at one month documented the complete recovery of 24 patients out of 25 without statistical difference with the younger group. This data was confirmed at 6-month follow-up. One patient died from cardiovascular failure 20 days after surgery. The presence of comorbidities, risk factors (antiplatelet therapy, anticoagulant therapy, history of alcohol abuse, and head trauma), preoperative symptoms, mono or bilateral CSDH, maximum thickness of hematoma, surgical time and recurrence were similar and statistically not significant in both groups. CONCLUSION: In this study, we demonstrate that surgery for very old patients above 90 years of age affected by CSDH is safe and allows complete recovery. Comparing two groups of patients above and under 90 years old we found that complication rate and recovery were similar in both groups.

Posterior Fossa Tumours in the First Year of Life: A Two-Centre Retrospective Study.

Posterior fossa tumours (PFTs) in infants are very rare, and information on these tumours is scarce in the literature. This retrospective study reports their pathological characteristics and describes surgical aspects and treatment outcomes. A two-centre cohort of infants with PFTs treated from 2007 to 2018 was retrospectively reviewed. Patient characteristics, clinical, and treatment data were reviewed. Survival curves for progression-free survival (PFS) and overall survival (OS) were generated. Thirty-three infants were retrieved. There were 11 low grade and 22 high-grade tumours. The most common presenting symptom was intracranial hypertension. Fifteen children out of thirty-three progressed. Five-year PFS was significantly lower in children with high-grade tumours (38.3%) than those with low-grade tumours (69.3%), p = 0.030. High-grade pathology was the only predictor of progression (HR 3.7, 95% CI 1.1-13.31), p = 0.045. Fourteen children with high-grade tumours died, with a 5-year OS of 55.25%. PFTs in children below one year of age still represent a unique challenge. Infants with high-grade tumours display the worst outcomes and the lowest survival, indicating that more effective strategies are needed.

A broad-spectrum sunscreen prevents UVA radiation-induced gene expression in reconstructed skin in vitro and in human skin in vivo.

The efficacy of sunscreens to protect against ultraviolet (UV) A radiation is usually assessed by measuring erythema formation and pigmentation. The biological relevance of these endpoints for UVA-induced skin damage, however, is not known. We therefore carried out two complementary studies to determine UVA protection provided by a broad-spectrum sunscreen product at a molecular level by studying UVA radiation-induced gene expression. One study was performed on human reconstructed skin in vitro with a semi-global gene expression analysis of 227 genes in fibroblasts and 244 in keratinocytes. The second one was conducted in vivo in human volunteers and focused on genes involved in oxidative stress response and photo-ageing (haeme oxygenase-1, superoxide dismutase-2, glutathione peroxidase, catalase, matrix metalloproteinase-1). In-vitro UVA radiation induced modulation of genes involved in extracellular matrix homeostasis, oxidative stress, heat shock responses, cell growth, inflammation and epidermal differentiation. Sunscreen pre-application abrogated or significantly reduced these effects, as underlined by unsupervised clustering analysis. The in vivo study confirmed that the sunscreen prevented UVA radiation-induced transcriptional expression of the five studied genes. These findings indicate the high efficacy of a broad-spectrum sunscreen in protecting human skin against UVA-induced gene responses and suggest that this approach is a biologically relevant complement to existing methods.

Bioactive tetrapeptide GEKG boosts extracellular matrix formation: in vitro and in vivo molecular and clinical proof.

The 'matrikine' concept claims that processing of the precursors for collagen results in the formation of peptides such as KTTKS which in turn augments extracellular matrix (ECM) production. In the present study, we show the development of an anti-ageing active from an in silico approach by molecular design resulting in the tetrapeptide GEKG derived from ECM proteins. The efficacy of the peptide to significantly induce collagen production of the protein level and mRNA level has been demonstrated in vitro in human dermal fibroblasts and in vivo in a double-blind, randomized, placebo-controlled study enroling 10 volunteers with an average age of 48.2 years. The effect of GEKG on facial wrinkles was studied in 30 volunteers using state of the art fringe projection, which allows determination of surface roughness in three-dimensions. Here, only GEKG but not the placebo was able to significantly decrease skin roughness as a measure for wrinkles.

Occipital interhemispheric transtentorial approach to a pineoblastoma in a 4-year-old child.

The authors present a pediatric case of a pineoblastoma treated with gross-total removal through an occipital interhemispheric transtentorial approach (OITA). The child presented with acute hydrocephalus that was treated by endoscopic third ventriculostomy (ETV) and tumor biopsy through a single burr hole. Histology revealed a pineoblastoma. Microsurgical total removal was performed 3 months after neoadjuvant chemotherapy. OITA was chosen on the basis of the tumor's location below the Herophilus-Galen line of sight. In this video, the authors show the positioning, the operating devices, the approach, and the microsurgical dissection, indicating all the neurovascular structures encountered. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2122.

Review of laminoplasty versus laminectomy in the surgical management of cervical spondylotic myelopathy.

BACKGROUND: We reviewed the literature comparing the indications/efficacy of laminectomy (LA) with or without fusion versus laminoplasty (LP) in the treatment of cervical spondylotic myelopathy (CSM). METHODS: We identified 14 studies in PubMed/Medline to include in our analysis. Outcomes were assessed utilizing the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), Neck Disability Index, and Nurick scale. Variables studied included ossification of the posterior longitudinal ligament (OPLL), cervical range of motion (ROM), the C2-C7 sagittal Cobb angle, the Ishihara index, and the Hirabayashi scale. Patients with cervical trauma/fracture, infection, or tumor were excluded from the study. RESULTS: In these 14 studies, there were no significant differences between LA and LP groups in terms of preoperative versus postoperative: JOA scores (e.g., including the improvement rate), VAS scores, and ROM. However, the LA patients demonstrated greater postoperative cervical lordosis versus those in the LP group. CONCLUSION: At present, there are no guidelines for choosing LA versus LP for treating CSM. Factors that should be considered when choosing one procedure over the other should include the patients' preoperative clinical status, the type of CSM, the pathological extent of OPLL, and whether there is a sufficient cervical lordotic curvature.

Factor XI deficiency and delayed hemorrhages after resection of choroid plexus papilloma: illustrative case.

BACKGROUND: Factor XI deficiency, also known as hemophilia C, is a rare inherited bleeding disorder that may leave routine coagulation parameters within normal range. Depending on the mutation subtype, prolonged activated partial thromboplastin time may occasionally be found. The disease has an autosomal transmission, with an estimated prevalence in the general population of approximately 1 in 1 million. Heterozygosis accounts for partial deficits, but the tendency to bleed is unrelated to the measured activity of factor XI. Diagnosis usually follows unexpected hemorrhages occurring spontaneously or after trauma or surgical procedures. OBSERVATIONS: Few cases have been reported in the neurosurgical literature, all occurring spontaneously or after head trauma. Owing to its subtle features, the true incidence of the disease is probably underestimated. The authors report a case of a patient with previously undiagnosed factor XI deficiency who underwent uncomplicated resection of a fourth-ventricle papilloma and experienced delayed, severe hemorrhagic complications. LESSONS: The known association between choroid plexus tumors and intracranial bleeding raised differential diagnosis issues. This report may serve to help to investigate delayed hemorrhages after cranial surgery.

Interhemispheric transcallosal transchoroidal approach to a pineal teratoma in a 15-year-old boy.

In this video, the authors present an interhemispheric transcallosal transchoroidal approach to a pineal mass in a 15-year-old boy. He received emergency endoscopic third ventriculostomy (ETV), then an endoscopic biopsy that revealed an immature teratoma. Surgical removal was selected. The mass was located very high in the posterior third ventricle, hidden behind the splenium of the corpus callosum and the vein of Galen, so an interhemispheric transcallosal approach followed by a complete dissection of the whole choroidal fissure was chosen and allowed complete removal of the tumor. Microsurgical dissection is presented, showing clearly in detail all the neurovascular structures encountered. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2126.