Assessment of brain response in operators subject to recoil force from firing long-range rifles.

Mild traumatic brain injury (mTBI) may be caused by occupational hazards military personnel encounter, such as falls, shocks, exposure to blast overpressure events, and recoil from weapon firing. While it is important to protect against injurious head impacts, the repeated exposure of Canadian Armed Forces (CAF) service members to sub-concussive events during the course of their service may lead to a significant reduction in quality of life. Symptoms may include headaches, difficulty concentrating, and noise sensitivity, impacting how personnel complete their duties and causing chronic health issues. This study investigates how the exposure to the recoil force of long-range rifles results in head motion and brain deformation. Direct measurements of head kinematics of a controlled population of military personnel during firing events were obtained using instrumented mouthguards. The experimentally measured head kinematics were then used as inputs to a finite element (FE) head model to quantify the brain strains observed during each firing event. The efficacy of a concept recoil mitigation system (RMS), designed to mitigate loads applied to the operators was quantified, and the RMS resulted in lower loading to the operators. The outcomes of this study provide valuable insights into the magnitudes of head kinematics observed when firing long-range rifles, and a methodology to quantify effects, which in turn will help craft exposure guidelines, guide training to mitigate the risk of injury, and improve the quality of lives of current and future CAF service members and veterans.

Vasopressin in newborns with refractory acute pulmonary hypertension.

BACKGROUND: Acute pulmonary hypertension (aPH) in newborns can be life threatening and challenging to manage. In newborns with refractory aPH, there is currently limited therapeutic agents. METHODS: Retrospective single-center cohort study in newborns less than one month old who were treated with vasopressin for a minimum of one hour in the context of refractory aPH in the neonatal and pediatric intensive care units of a tertiary university center between 2016 and 2022. The objective was to evaluate the efficacy and safety of vasopressin in newborns as an adjuvant treatment for refractory aPH. RESULTS: Twenty-five patients met inclusion criteria. In patients who received vasopressin, oxygenation index improved from 28.4 to 14.4 (p = 0.004) after twelve hours of continuous infusion. Oxygen requirements (FiO2) decreased from 0.91 to 0.50 (p = 0.004) and mean arterial pressure increased from 41 to 51 mmHg (p = 0.001). In our cohort, 68% of patients presented an episode of hyponatremia (serum sodium <130 mmol/L). CONCLUSIONS: The use of vasopressin may be associated with improvement in oxygenation and hemodynamic status of neonatal patients with aPH refractory to initial therapy. Further prospective studies are needed to establish the safety profile of vasopressin in newborns, particularly in preterm infants. IMPACT: Vasopressin may be an effective cardiotropic agent to improve oxygenation and hemodynamic status in newborns with acute pulmonary hypertension. Careful monitoring of serum sodium levels are warranted in newborns who are receiving vasopressin infusion. This provides additional evidence for the consideration of vasopressin in newborns with acute pulmonary hypertension refractory to inhaled nitric oxide.

A technique for in situ intracranial strain measurement within a helmeted deformable headform.

Despite the broad use of helmets, incidence of concussion remains high. Current methods for helmet evaluation focus on the measurement of head kinematics as the primary tool for quantifying risk of brain injury. Though the primary cause of mild Traumatic Brain Injury (mTBI) is thought to be intracranial strain, helmet testing methodologies are not able to directly resolve these parameters. Computational injury models and impact severity measures are currently used to approximate intracranial strains from head kinematics and predict injury outcomes. Advancing new methodologies that enable experimental intracranial strain measurements in a physical model would be useful in the evaluation of helmet performance. This study presents a proof-of-concept head surrogate and novel helmet evaluation platform that allows for the measurement of intracranial strain using high-speed X-ray digital image correlation (XDIC). In the present work, the head surrogate was subjected to a series of bare and helmeted impacts using a pneumatically-driven linear impactor. Impacts were captured at 5,000 fps using a high-speed X-ray cineradiography system, and strain fields were computed using digital image correlation. This test platform, once validated, will open the door to using brain tissue-level measurements to evaluate helmet performance, providing a tool that can be translated to represent mTBI injury mechanisms, benefiting the helmet design processes.

A Preliminary Step Towards a Physical Surrogate of the Human Calvarium to Model Fracture.

A surrogate model of the human calvarium can be used to assess skull-fracture-related head injuries without continuously requiring post-mortem human skulls. Skull simulants developed in the literature often require sophisticated manufacturing procedures and/or materials not always practical when factoring in time or expense considerations. This study's objective was to fabricate three exploratory surrogate models (1. pure epoxy prototype, 2. epoxy-chalk mix prototype, and 3. epoxy-chalk three-layered prototype) of the calvarium to mimic the calvarium's mechanical response at fracture using readily available and cost-effective materials, specifically epoxy and chalk. The surrogates and calvaria were subject to quasi-static and dynamic impact 4-point bending and their mechanical responses were compared statistically. Under quasi-static loading, all three surrogates showed a considerable number of differences in mechanical response variables to calvaria that was deemed significant (p < 0.05). Under dynamic impact loading, there was no sufficient evidence to reject that the average mechanical response variables were equal between the epoxy-chalk three-layered prototype and calvaria (p > 0.05). This included force and bending moment at fracture, tensile strain at fracture, tensile and compressive stress at fracture, tensile modulus, and tensile strain rate. Overall, our study illustrates two main remarks: (1) the three exploratory surrogate models are potential candidates for mimicking the mechanical response of the calvarium at fracture during impact loading and (2) employing epoxy and chalk, which are readily available and cost-effective has the potential to mimic the mechanical response of calvaria in impact loading.

Adaptation and Validation of the Standardized Swallowing Assessment Tool for Patients With Moderate-Severe Traumatic Brain Injury and Cervical Spinal Cord Injury.

Oropharyngeal dysphagia is common in moderate-severe traumatic brain injury (TBI) and cervical spinal cord injury (SCI) patients and can have serious consequences. Delaying feeding in these patients can also be detrimental. Nonetheless, the psychometric properties of screening tools that can promptly identify dysphagia have never been tested in these neurotrauma populations. This study aimed to: (1) adapt, translate, and validate the content of the French-Canadian version of the the Standardized Swallowing Assessment (SSA) tool to meet the needs of moderate-severe TBI and cervical SCI patients, (2) examine its inter-rater reliability and criterion-concurrent validation, and (3) evaluate its clinical utility from the perspectives of critical care nurses. The SSA tool was adapted and translated using an integrated method for the cultural adaptation and translation of tools. Eleven experts participated in the adaptation of the SSA tool, which led to the clarification of one item, as well as a new step and instructions for the screening procedure. Content validation (i.e., item and scale relevance) was evaluated by multidisciplinary team members (n = 17). The mean content validity index (CVI) score was 0.97 for the entire scale, while the mean CVI scores for individual items ranged from 0.82 to 1.0. A total of 60 neurotrauma patients were enrolled for inter-rater reliability and criterion-concurrent validation. Interrater reliability was determined by comparing two scores: one score from nurses responsible for the care of enrolled patients and one score from the research nurse. The weighted kappa coefficients for inter-rater reliability were 0.86 for moderate-severe TBI patients (n = 30) and 0.73 for cervical SCI patients (n = 30). A speech language therapist (SLT) also assessed dysphagia and results were used as the standard clinical reference criterion to determine concurrent validity (sensibility and specificity) of the adapted SSA tool. The sensitivity and specificity were 92% and 50% for moderate-severe TBI, and 77% and 75% for cervical SCI, respectively. The positive predictive value (PPV) and the negative predictive value (NPV) were 65% and 87% in TBI patients, and 75% and 76% in SCI patients. Test accuracy was 71% and 77% for these same groups. The clinical utility of the tool was evaluated according to the following domains: appropriateness, accessibility of the required material, applicability, perceived effectiveness, and acceptability. Acceptability was the only domain with a level of agreement <80% (74%) among trauma critical care nurses (n = 49). Findings support the content validation and inter-rater reliability of the adapted French-Canadian version of the SSA tool in moderate-severe TBI and cervical SCI patients. Sensitivity was acceptable in both groups, but the specificity was lower, especially in moderate-severe TBI patients. Further validation of the adapted French-Canadian version of the SSA tool is needed in neurotrauma patients to confirm these results and to ensure safe dysphagia screening while avoiding oral feeding deferrals.

The effect of morphometric and geometric indices of the human calvarium on mechanical response.

BACKGROUND: When developing a surrogate model of the human skull, there is a multitude of morphometric and geometric properties to consider when constructing the model. To simplify this approach, it is important to identify only the properties that have a significant influence on the mechanical response of the skull. The objective of this study was to identify which morphometric and geometric properties of the calvarium were significant predictors of mechanical response. METHODS: Calvarium specimens (N = 24) were micro-computed tomography scanned to determine morphometric and geometric properties. The specimens were assumed to be Euler-Bernoulli beams and were subject to 4-point quasi-static bending to determine mechanical response. Univariate linear regressions were performed whereby the morphometric and geometric properties were independent or predictor variables and the mechanical responses were dependent or outcome variables. FINDINGS: Nine significant linear regression models were established (p < 0.05). In the diploë, trabecular bone pattern factor was a significant predictor of force and bending moment at fracture. The inner cortical table had more significant predictors (thickness, tissue mineral density, and porosity) of mechanical response compared to the outer cortical table and diploë. INTERPRETATION: Morphometric and geometric properties had a key influence on the calvarium's biomechanics. Trabecular bone pattern factor and the morphometry and geometry of the cortical tables must be considered when evaluating the mechanical response of the calvarium. These properties can aid the design of surrogate models of the skull that seek to mimic its mechanical response for head impact simulation.

Educational needs and preferences of adult patients with acute or chronic pain: a mixed methods systematic review protocol.

OBJECTIVES: This review will aim to synthesize the available quantitative and qualitative evidence on the educational needs and preferences of adult patients with acute or chronic pain. INTRODUCTION: Acute and chronic pain are prevalent problems and are associated with significant individual and societal consequences. Education is a critical component of pain management. However, the impact of educational interventions on pain outcomes remains limited. The lack of patient input--what patients want to know and how they want to be informed--is one of the main issues underlying intervention design. INCLUSION CRITERIA: We will include qualitative, quantitative, and mixed methods studies describing the educational needs and preferences of adult patients with acute or chronic pain. METHODS: This review will follow the JBI guidelines for mixed methods systematic reviews. We will search MEDLINE (PubMed), Embase (Ovid), PsycINFO (Ovid), CINAHL (EBSCO), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and ProQuest Dissertations and Theses. The search strategy will commence from the year 1990 onward and there will be no language restrictions. The retrieved titles, abstracts, and full-text reports will be screened by pairs of independent reviewers. These pairs of reviewers will also independently extract data using the JBI tools for mixed methods systematic reviews. Methodological quality will be assessed using the mixed methods appraisal tool. A convergent integrated approach to synthesis and integration of the quantitative and qualitative data will be used. REVIEW REGISTRATION: PROSPERO CRD42022303834.

Influence of surrogate scalp material and thickness on head impact responses: Toward a biofidelic head-brain physical model.

Advanced physical head models capable of replicating both global kinematics and intracranial mechanics of the human head are required for head injury research and safety gear assessment. These head surrogates require a complex design to accommodate realistic anatomical details. The scalp is a crucial head component, but its influence on the biomechanical response of such head surrogates remains unclear. This study aimed to evaluate the influence of surrogate scalp material and thickness on head accelerations and intraparenchymal pressures using an advanced physical head-brain model. Scalp pads made from four materials (Vytaflex20, Vytaflex40, Vytaflex50, PMC746) and each material with four thicknesses (2, 4, 6, and 8 mm) were evaluated. The head model attached to the scalp pad was dropped onto a rigid plate from two heights (5 and 19.5 cm) and at three head locations (front, right side, and back). While the selected materials' modulus exhibited a relatively minor effect on head accelerations and coup pressures, the effect of scalp thickness was shown to be major. Moreover, by decreasing the thickness of the head's original scalp by 2 mm and changing the original scalp material from Vytaflex 20 to Vytaflex 40 or Vytaflex 50, the head acceleration biofidelity ratings could improve by 30% and approached the considered rating (0.7) of good biofidelity. This study provides a potential direction for improving the biofidelity of a novel head model that might be a useful tool in head injury research and safety gear tests. This study also has implications for selecting appropriate surrogate scalps in the future design of physical and numerical head models.

Evaluating the Intracranial Pressure Biofidelity and Response Repeatability of a Physical Head-Brain Model in Frontal Impacts.

Headforms are widely used in head injury research and headgear assessment. Common headforms are limited to replicating global head kinematics, although intracranial responses are crucial to understanding brain injuries. This study aimed to evaluate the biofidelity of intracranial pressure (ICP) and the repeatability of head kinematics and ICP of an advanced headform subjected to frontal impacts. Pendulum impacts were performed on the headform using various impact velocities (1-5 m/s) and impactor surfaces (vinyl nitrile 600 foam, PCM746 urethane, and steel) to simulate a previous cadaveric experiment. Head linear accelerations and angular rates in three axes, cerebrospinal fluid ICP (CSFP), and intraparenchymal ICP (IPP) at the front, side, and back of the head were measured. The head kinematics, CSFP, and IPP demonstrated acceptable repeatability with coefficients of variation generally being less than 10%. The BIPED front CSFP peaks and back negative peaks were within the range of the scaled cadaver data (between the minimum and maximum values reported by Nahum et al.), while side CSFPs were 30.9-92.1% greater than the cadaver data. CORrelation and Analysis (CORA) ratings evaluating the closeness of two time histories demonstrated good biofidelity of the front CSFP (0.68-0.72), while the ratings for the side (0.44-0.70) and back CSFP (0.27-0.66) showed a large variation. The BIPED CSFP at each side was linearly related to head linear accelerations with coefficients of determination greater than 0.96. The slopes for the BIPED front and back CSFP-acceleration linear trendlines were not significantly different from cadaver data, whereas the slope for the side CSFP was significantly greater than cadaver data. This study informs future applications and improvements of a novel head surrogate.

Strategies to improve the quality of nurse triage in emergency departments: A realist review protocol.

AIM: The purpose of this realist review was to assess what works, for whom and in what context, regarding strategies that influence nurses' behaviour to improve triage quality in emergency departments (ED). DESIGN: Realist review protocol. METHODS: This protocol follows the PRISMA-P statement and will include any type of study on strategies to improve the triage process in the ED (using recognized and validated triage scales). The included studies were examined for scientific quality using the Mixed Methods Appraisal Tool. The framework for this realist review is based on the Behaviour Change Wheel (BCW) and the context-mechanism-outcome (CMO) models. DISCUSSION: Nurses and ED decision makers will be informed on the evidence regarding strategies to improve the quality of triage and the factors required to maximize their effectiveness. Research gaps may also be identified to guide future research projects on the adoption of best practices in ED nursing triage.

The Mechanical Characterization and Comparions of Male and Female Calvaria Under Four-Point Bending Impacts.

The circumstances in which we mechanically test and critically assess human calvarium tissue would find relevance under conditions encompassing real-world head impacts. These conditions include, among other variables, impact velocities, and strain rates. Compared to quasi-static loading on calvaria, there is less reporting on the impact loading of the calvaria and consequently, there are relatively fewer mechanical properties on calvaria at relevant impact loading rates available in the literature. The purpose of this work was to report on the mechanical response of 23 human calvarium specimens subjected to dynamic four-point bending impacts. Impacts were performed using a custom-built four-point impact apparatus at impact velocities of 0.86-0.89 m/s resulting in surface strain rates of 2-3/s-representative of strain rates observed in vehicle collisions and blunt impacts. The study revealed comparable effective bending moduli (11-15 GPa) to the limited work reported on the impact mechanics of calvaria in the literature, however, fracture bending stress (10-47 MPa) was relatively less. As expected, surface strains at fracture (0.21-0.25%) were less compared to studies that performed quasi-static bending. Moreover, the study revealed no significant differences in mechanical response between male and female calvaria. The findings presented in this work are relevant to many areas including validating surrogate skull fracture models in silico or laboratory during impact and optimizing protective devices used by civilians to reduce the risk of a serious head injury.

Review of Mechanisms and Research Methods for Blunt Ballistic Head Injury.

Head injuries account for 15%-20% of all military injuries and pose a high risk of causing functional disability and fatality. Blunt ballistic impacts are one of the threats that can lead to severe head injuries. This review aims to examine the mechanisms and injury risk assessment associated with blunt ballistic head injury (BBHI). The review further discusses research methods and instrumentation used in BBHI studies, focusing on their limitations and challenges. Studies on the mechanisms of focal and diffuse brain injuries remain largely inconclusive and require further effort. Some studies have attempted to associate BBHIs with head mechanics, but more research is required to establish correlations between head mechanics and injury severity. Limited access to experimental models and a lack of instrumentation capable of measuring the mechanics of brain tissue in situ are potential reasons for the lack of understanding of injury mechanisms, injury correlations, and injury tolerance levels specific to this loading regime. Targeted research for understanding and assessing head injuries in blunt ballistic impacts is a necessary step in improving our ability to design protection systems to mitigate these injuries.

In Situ Strain Measurements Within Helmet Padding During Linear Impact Testing.

Drop and Impact testing of helmets are used extensively in the design process and eventual certification of helmets. These techniques have traditionally relied heavily on the measurement of the kinematic response to impact, which provides an indirect measurement of the liner response that is subject to interpretation during the design process. In the present work, we introduce an in situ experimental technique that provides a time-resolved measurement of the deformation of the helmet and its components during an impact event. The data collected from a high-speed X-ray imaging system can provide a full description of the deformation at the component level, which provides a helmet designer further insight into the performance of their helmet, while also returning the traditional kinematic metrics. The data presented focuses on the deformation of a commercial hockey helmet subjected to a series of linear impacts with three different impactor caps at speeds ranging from 2.4 to 4.5 m/s. Deformation of the liner was monitored in the midsagittal and a parasagittal plane of the helmet. The results show that there is a clear dependence on the maximum strain achieved in the foam that is dependent on the impact type, the impactor shape, and the resulting strain rate of deformation in the foam liner. These techniques can provide the first data for a direct validation and calibration of finite element helmet deformation models, while also providing a new tool-set to improve the efficacy of helmet design.

Evaluation of the Kinematic Biofidelity and Inter-Test Repeatability of Global Accelerations and Brain Parenchyma Pressure for a Head-Brain Physical Model.

Head surrogates are widely used in biomechanical research and headgear assessment. They are designed to approximate the inertial and mechanical properties of the head and are instrumented to measure global head kinematics. Due to the recent interest in studying disruption to the brain, some head models include internal fluid layers and brain tissue, and instrumentation to measure head intracranial biomechanics. However, it is unknown whether such models exhibit realistic human responses. Therefore, this study aims to assess the biofidelity and repeatability of a head model, the Blast Injury Protection Evaluation Device (BIPED), that can measure both global head kinematics and intraparenchymal pressure (IPP) for application in blunt impact, a common loading scenario in civilian life. Drop tests were conducted with the BIPED and the widely used Hybrid III headform. BIPED measures were compared to the Hybrid III data and published cadaveric data, and the biofidelity level of the global linear acceleration was quantified using CORrelation and Analysis (CORA) ratings. The repeatability of the acceleration and IPP measurements in multiple impact scenarios was evaluated via the coefficient of variation (COV) of the magnitudes and pulse durations. BIPED acceleration peaks were generally not significantly different from cadaver and Hybrid III data. The CORA ratings for the BIPED and Hybrid III accelerations ranged from 0.50 to 0.61 and 0.51 to 0.77, respectively. The COVs of acceleration and IPP were generally below 10%. This study is an important step toward a biofidelic head surrogate measuring both global kinematics and IPP in blunt impact.

Cortical and trabecular morphometric properties of the human calvarium.

There is currently a gap in the literature that quantitatively describes the complex bone microarchitecture within the diploë (trabecular bone) and cortical layers of the human calvarium. The purpose of this study was to determine the morphometric properties of the diploë and cortical tables of the human calvarium in which key interacting factors of sex, location on the calvarium, and layers of the sandwich structure were considered. Micro-computed tomography (micro-CT) was utilized to capture images at 18 µm resolution of male (n = 26) and female (n = 24) embalmed calvarium specimens in the frontal and parietal regions (N = 50). All images were post-processed and analyzed using vendor bundled CT-Analyzer software to determine the morphometric properties of the diploë and cortical layers. A two-way mixed (repeated measures) analysis of variance (ANOVA) was used to determine diploë morphometric properties accounting for factors of sex and location. A three-way mixed ANOVA was performed to determine cortical morphometric properties accounting for factors of cortical layer (inner and outer table), sex, and location. The study revealed no two-way interaction effects between sex and location on the diploë morphometry except for fractal dimension. Trabecular thickness and separation in the diploë were significantly greater in the male specimens; however, females showed a greater number of trabeculae and fractal dimension on average. Parietal specimens revealed a greater porosity, trabecular separation, and deviation from an ideal plate structure, but a lesser number of trabeculae and connectivity compared to the frontal location. Additionally, the study observed a lower density and greater porosity in the inner cortical layer than the outer which may be due to clear distinctions between each layer's physiological environment. The study provides valuable insight into the quantitative morphometry of the calvarium in which finite element modelers of the skull can refer to when designing detailed heterogenous or subject-specific skull models to effectively predict injury. Furthermore, this study contributes towards the recent developments on physical surrogate models of the skull which require approximate measures of calvarium bone architecture in order to effectively fabricate a model and then accurately simulate a traumatic head impact event.

Protective Headgear Attenuates Forces on the Inner Table and Pressure in the Brain Parenchyma During Blast and Impact: An Experimental Study Using a Simulant-Based Surrogate Model of the Human Head.

Military personnel sustain head and brain injuries as a result of ballistic, blast, and blunt impact threats. Combat helmets are meant to protect the heads of these personnel during injury events. Studies show peak kinematics and kinetics are attenuated using protective headgear during impacts; however, there is limited experimental biomechanical literature that examines whether or not helmets mitigate peak mechanics delivered to the head and brain during blast. While the mechanical links between blast and brain injury are not universally agreed upon, one hypothesis is that blast energy can be transmitted through the head and into the brain. These transmissions can lead to rapid skull flexure and elevated pressures in the cranial vault, and, therefore, may be relevant in determining injury likelihood. Therefore, it could be argued that assessing a helmet for the ability to mitigate mechanics may be an appropriate paradigm for assessing the potential protective benefits of helmets against blast. In this work, we use a surrogate model of the head and brain to assess whether or not helmets and eye protection can alter mechanical measures during both head-level face-on blast and high forehead blunt impact events. Measurements near the forehead suggest head protection can attenuate brain parenchyma pressures by as much as 49% during blast and 52% during impact, and forces on the inner table of the skull by as much as 80% during blast and 84% during impact, relative to an unprotected head.

The impact of targeted therapy on healthcare resource use in patients with metastatic renal cell carcinoma: The University of Sherbrooke experience.

INTRODUCTION: We assessed the impact of targeted therapies on healthcare resource use and compared treatment regimens used in patients diagnosed with metastatic renal cell carcinoma (mRCC). METHODS: Clinicopathological and administrative data of patients with mRCC from our institution were retrospectively collected from January 2000 to August 2014. Patients were divided into two groups based on the use of targeted therapies. Healthcare resource use (HCRU) data included non-scheduled total number of hospitalizations, total days hospitalized, emergency department visits, and healthcare professional consultations. Each variable was presented with absolute and relative values (i.e., per month of survival). Statistics relied on the use of t-student and Chi-square tests. RESULTS: Ninety-nine patients were included in the study; 60 were treated with targeted therapy. There were no statistically significant differences between the two groups for demographic features and clinicopathological stage. HCRU analysis revealed an absolute increase in the median number of healthcare consultants (6 vs. 4; p<0.01) and emergency department visits (1 vs. 0; p=0.02) for the targeted therapy group. However, analysis per month of survival showed the targeted therapy group had fewer consultants (0.33 vs. 0.40; p=0.04) and hospitalizations (0.09 vs. 0.13; p=0.03) than their counterpart. Population size, non-randomization, treatment selection bias, and heterogeneity were the main limitations of this study. CONCLUSIONS: Monthly use of HCRU is lower in mRCC patients treated with targeted therapies. However, because of a greater overall survival, their absolute total HCRU will be higher than those not exposed to targeted agents.

Metastatic renal cell carcinoma initially presenting with hematochezia and subsequently with vaginal bleeding: a case report.

BACKGROUND: We report an unusual case of a synchronous rectal and metachronous vaginal metastatic renal cell carcinoma. CASE PRESENTATION: A 78-year-old woman presented with hematochezia and a colonoscopy revealed a metastatic clear-cell renal cell carcinoma rectal polyp biopsy-proven. Abdominal computed tomography identified a 9.0-cm left renal mass with renal vein thrombosis, for which she underwent a laparoscopic radical nephrectomy. Histopathological examination confirmed a pT3a clear-cell renal cell carcinoma. Seven months later, the patient presented with vaginal bleeding. Physical examination revealed a vaginal polypoid mass and biopsy confirmed a clear-cell renal cell carcinoma metastasis. CONCLUSIONS: This case represents unusual manifestations of metastatic renal cell carcinoma and is a reminder of the wide spectrum of clinical course of this disease.