RNF213-Related Vasculopathy: Various Systemic Vascular Diseases Involving RNF213 Gene Mutations: Review.

Moyamoya disease (MMD) is a cerebrovascular disorder that is predominantly observed in women of East Asian descent, and is characterized by progressive stenosis of the internal carotid artery, beginning in early childhood, and a distinctive network of collateral vessels known as "moyamoya vessels" in the basal ganglia. Additionally, a prevalent genetic variant found in most MMD cases is the p.R4810K polymorphism of RNF213 on chromosome 17q25.3. Recent studies have revealed that RNF213 mutations are associated not only with MMD, but also with other systemic vascular disorders, including intracranial atherosclerosis and systemic vascular abnormalities such as pulmonary artery stenosis and coronary artery diseases. Therefore, the concept of "RNF213-related vasculopathy" has been proposed. This review focuses on polymorphisms in the RNF213 gene and describes a wide range of clinical and genetic phenotypes associated with RNF213-related vasculopathy. The RNF213 gene has been suggested to play an important role in the pathogenesis of vascular diseases and developing new therapies. Therefore, further research and knowledge sharing through collaboration between clinicians and researchers are required.

Lung adenocarcinoma metastasis within a pituitary neuroendocrine tumor: a case report with review of literature.

Collision tumors involving the metastasis of malignant neoplasms to pituitary neuroendocrine tumors (PitNETs) are extremely rare. We herein report a case involving a patient with lung adenocarcinoma metastasis within a PitNET who exhibited relatively rapid progression of neurological symptoms. A 75-year-old man who underwent tumor resection 36 and 18 years prior to presentation for bladder and colon cancer, respectively, without recurrence presented with bitemporal hemianopsia, ptosis, and diplopia of the right eye. Subsequent magnetic resonance imaging (MRI) revealed a tumor 3.2 cm in diameter that extended from the anterior pituitary gland to the suprasellar region. Gadolinium-enhanced MRI of the tumor showed heterogeneous contrast enhancement. Considering the relatively rapid progression of neurological symptoms, semi-emergency endoscopic endonasal transsphenoidal surgery was performed. Histopathological examination revealed a group of thyroid transcription factor-1- and napsin A-positive papillary proliferating cells intermingled with α-subunit- and steroidogenic factor-1-positive PitNET cells. Thus, the patient was diagnosed with lung adenocarcinoma metastasis within a gonadotroph PitNET. Genetic testing revealed the presence of an EGFR (Ex-19del) mutation, after which chemotherapy was initiated. Additional stereotactic radiotherapy was performed for the residual tumor in the sella turcica. With continued chemotherapy, good control of both the primary and metastatic tumors was noted after 24 months after surgery. Cases of malignant neoplasm metastasis within a PitNET are difficult to diagnose. In the case of a sella turcica tumor with relatively rapid progression of neurological symptoms, early surgical intervention is recommended given the possibility of a highly proliferative tumor and the need to obtain pathologic specimens.

Endoscopic spinal cord untethering using a 1 cm skin incision technique in pediatrics: a technical case report.

BACKGROUND: Spinal cord untethering by sectioning the filum terminale is commonly performed in tethered cord syndrome patients with minor abnormalities such as filar lipoma, thickened filum terminale, and low conus medullaris. Our endoscopic surgical technique, using the interlaminar approach, allows for sectioning the filum terminale through a very small skin incision. To our knowledge, this procedure has not been previously reported. This is the first case report involving a 1 cm skin incision. CASE PRESENTATION: A 9-month-old male patient was referred to our neurosurgical department due to a coccygeal dimple. MRI revealed a thickened fatty filum. After considering the treatment options for this patient, the parents agreed to spinal cord untethering. A midline 1 cm skin incision was made at the L4/5 vertebral level. Untethering by sectioning the filum terminale was performed by full endoscopic surgery using the interlaminar approach. The procedure was uneventful and there were no postoperative complications. CONCLUSIONS: In terms of visibility and minimizing invasiveness, our surgical technique of using the interlaminar approach with endoscopy allows for untethering by sectioning the filum terminale through a very small skin incision.

Concurrent IgG4-related hypophysitis and clinically nonfunctioning gonadotroph pituitary neuroendocrine tumor.

BACKGROUND: Some patients develop immunoglobulin G4 (IgG4)-related hypophysitis associated with systemic diseases. More than 30 cases of IgG4-related hypophysitis have been reported. However, biopsy has rarely been performed in these patients, and none have had an associated pituitary neuroendocrine tumor (PitNET). We present a case of concurrent IgG4-related hypophysitis and PitNET. CASE PRESENTATION: A 56-year-old Japanese man arrived at the hospital with visual impairment, bitemporal hemianopia, and right abducens nerve palsy. Magnetic resonance imaging revealed pituitary body and stalk swelling as well as a small poorly enhanced right anterior lobe mass. Laboratory and loading test results suggested hypopituitarism. Because IgG4 level was elevated, a systemic examination was performed; multiple nodules were found in both lung fields. The diagnosis was based on an endoscopic transnasal biopsy of the pituitary gland. A histopathological examination revealed a marked infiltration of plasma cells into the pituitary gland, which was strongly positive for IgG4. The histological features of the resected tumor were consistent with those of gonadotroph PitNET, which was immunohistochemically positive for follicle-stimulating hormone-ß and steroidogenic factor-1, and no plasma cell infiltration was observed. Based on the histopathological examination results, steroid therapy was initiated, which reduced pituitary gland size and serum IgG4 levels. DISCUSSION AND CONCLUSIONS: This is the first reported case of IgG4-related hypophysitis with PitNET. Although no pathological findings indicating a relationship between the two conditions were found, we were able to preoperatively differentiate multiple lesions via detailed diagnostic imaging.

Creation of low cost, simple, and easy-to-use training kit for the dura mater suturing in endoscopic transnasal pituitary/skull base surgery.

Training kits for laparoscopes for deep suturing under endoscopes are commercially available; however, previously reported training kits for endoscopic transnasal transsphenoidal pituitary/skull base surgery (eTSS) were not available in the market. Moreover, the previously reported low cost, self-made kit has the drawback of being unrealistic. This study aimed to create a low cost training kit for eTSS dura mater suturing that was as close to real as possible. Most necessary items were obtained from the 100-yen store ($1 store) or from everyday supplies. As an alternative to the endoscope, a stick-type camera was used. Through the assembly of the materials, a simple and easy-to-use training kit was created, which is almost identical to the actual dural suturing situation. In eTSS, a simple and easy-to-use training kit for dural suturing was successfully created at a low cost. This kit is expected to be used for deep suture operations and the development of surgical instruments for training.

An Overview of Pituitary Incidentalomas: Diagnosis, Clinical Features, and Management.

Pituitary incidentalomas are tumors or mass lesions of the pituitary gland. These are incidentally discovered during imaging studies for symptoms that are not causally related to pituitary diseases. The most common symptom that triggers an examination is headache, and the most common type of pituitary incidentalomas are pituitary neuroendocrine tumors (PitNETs) and Rathke cleft cysts. The existing treatment strategy is controversial; however, surgical resection is recommended in cases of clinically non-functioning PitNETs with optic chiasm compression. In contrast, cystic lesions, such as Rathke cleft cysts, should be followed if the patients are asymptomatic. In this case, MRI and pituitary function tests are recommended every six months to one year; if there is no change, the follow-up period should be extended. The natural history of PitNET is partially known, and the management of pituitary incidentalomas is determined by this history. However, the pathogenesis of PitNET has significantly changed with the new World Health Organization classification, and follow-up is important based on this new classification. Therefore, a high level of evidence-based research is needed to consider treatment guidelines for pituitary incidentalomas in the future.

Factors Influencing Long-Term Blood Flow in Extracranial-to-Intracranial Bypass for Symptomatic Internal Carotid Artery Occlusive Disease: A Quantitative Study.

BACKGROUND: Maintaining the patency of extracranial-to-intracranial (EC-IC) bypass is critical for long-term stroke prevention. However, reports on the factors influencing long-term bypass patency and quantitative assessments of bypass patency are limited. OBJECTIVE: To quantitatively evaluate blood flow in EC-IC bypass using four-dimensional (4D) flow magnetic resonance imaging (MRI) and investigate factors influencing the long-term patency of EC-IC bypass. METHODS: Thirty-six adult Japanese patients who underwent EC-IC bypass for symptomatic internal carotid or middle cerebral artery occlusive disease were included. We examined the relationships between decreased superficial temporal artery (STA) blood flow volume and perioperative complications, long-term ischemic complications, patient background, and postoperative antithrombotic medications in patients for whom STA flow could be quantitatively assessed for at least 5 months using 4D flow MRI. RESULTS: The mean follow-up time was 54.7 ± 6.1 months. One patient presented with a stroke during the acute postoperative period that affected postoperative outcomes. No recurrent strokes were recorded during long-term follow-up. Two patients died of malignant disease. Seven cases of reduced flow occurred in the STA, which were correlated with single bypass (P = .0294) and nonuse of cilostazol (P = .0294). STA occlusion was observed in 1 patient during the follow-up period. Hypertension, age, smoking, dyslipidemia, and diabetes mellitus were not correlated with reduced blood flow in the STA. CONCLUSION: Double anastomoses and cilostazol resulted in long-term STA blood flow preservation. No recurrence of cerebral infarction was noted in either STA hypoperfusion or occlusion cases.

Use of a Contest Format for Objective Assessment of Microsurgical Technique: An Observational Study.

BACKGROUND: Few studies have used simulation models to examine long-term improvement in microsurgical technique. We investigated whether improvement in surgical technique could be assessed by continuous, objective, contest-format evaluation of the same microsurgical task. METHODS: Since 2014, neurosurgeons with 1-10 years of experience participated in a biannual competition-format test. The task involved creating as many sutures as possible during the 5-minute interval after arteriotomy of a 1-mm artificial vessel. A modified version of the Objective Structured Assessment of Technical Skills examination was created and used. Changes and differences in scores over time were examined for each evaluator. RESULTS: Overall, 103 neurosurgeons participated in the study at least once, and those who participated more than once were divided into two groups: those who had the highest score in each contest and those who had the lowest score. The linear regression equations for the highest and lowest scorers were y=7.62x+81.56 (R2=0.628) and y=1.94x+67.93 (R2=0.0433), respectively. High scorers had high scores from the first time they participated, and their scores tended to increase further, while scores for low scorers tended not to increase with additional experience. Scores for the four evaluators did not significantly differ. CONCLUSIONS: Our results suggest that technical improvement in surgery can be assessed by long-term, continuous evaluation of microsurgical technique and that the present evaluation system might help increase surgical safety.

Ring finger protein 213 c.14576G>A mutation is not involved in internal carotid artery and middle cerebral artery dysplasia.

The ring finger protein 213 (RNF213) susceptibility gene has been detected in more than 80% of Japanese and Korean patients with moyamoya disease (MMD), a bilateral internal carotid artery (ICA) occlusion. Furthermore, RNF213 has been detected in more than 20% of East Asians with atherosclerotic ICA stenosis. In this study, we evaluated the frequency of RNF213 mutations in congenital occlusive lesions of the ICA system. This case series was conducted jointly at four university hospitals. Patients with a family history of MMD, quasi-MMD, or related diseases were excluded. Ten patients were diagnosed with abnormal ICA or middle cerebral artery (MCA) angiogenesis. Patients with neurofibromatosis were excluded. Finally, nine patients with congenital vascular abnormalities were selected; of these, five had ICA deficiency and four had twig-like MCA. The RNF213 c.14576G > A mutation was absent in all patients. Therefore, the RNF213 c.14576G > A mutation may not be associated with ICA and MCA congenital dysplasia-rare vascular anomalies making it difficult to study a large number of cases. However, an accumulation of cases is required for accurate determination. The results of this study may help differentiate congenital vascular diseases from MMD.

RNF213 c.14576G>A Is Associated with Intracranial Internal Carotid Artery Saccular Aneurysms.

A mutation in RNF213 (c.14576G>A), a gene associated with moyamoya disease (>80%), plays a role in terminal internal carotid artery (ICA) stenosis (>15%) (ICS). Studies on RNF213 and cerebral aneurysms (AN), which did not focus on the site of origin or morphology, could not elucidate the relationship between the two. However, a report suggested a relationship between RNF213 and AN in French-Canadians. Here, we investigated the relationship between ICA saccular aneurysm (ICA-AN) and RNF213. We analyzed RNF213 expression in subjects with ICA-AN and atherosclerotic ICS. Cases with a family history of moyamoya disease were excluded. AN smaller than 4 mm were confirmed as AN only by surgical or angiographic findings. RNF213 was detected in 12.2% of patients with ICA-AN and 13.6% of patients with ICS; patients with ICA-AN and ICS had a similar risk of RNF213 mutation expression (odds ratio, 0.884; 95% confidence interval, 0.199-3.91; p = 0.871). The relationship between ICA-AN and RNF213 (c.14576G>A) was not correlated with the location of the ICA and bifurcation, presence of rupture, or multiplicity. When the etiology and location of AN were more restricted, the incidence of RNF213 mutations in ICA-AN was higher than that reported in previous studies. Our results suggest that strict maternal vessel selection and pathological selection of AN morphology may reveal an association between genetic mutations and ICA-AN development. The results of this study may form a basis for further research on systemic vascular diseases, in which the RNF213 (c.14576G>A) mutation has been implicated.

Role of RNF213 polymorphism in defining quasi-moyamoya disease and definitive moyamoya disease.

OBJECTIVE: Quasi-moyamoya disease (QMMD) is moyamoya disease (MMD) associated with additional underlying diseases. Although the ring finger protein 213 (RNF213) c.14576G>A mutation is highly correlated with MMD in the Asian population, its relationship to QMMD is unclear. Therefore, in this study the authors sought to investigate the RNF213 c.14576G>A mutation in the genetic diagnosis and classification of QMMD. METHODS: This case-control study was conducted among four core hospitals. A screening system for the RNF213 c.14576G>A mutation based on high-resolution melting curve analysis was designed. The prevalence of RNF213 c.14576G>A was investigated in 76 patients with MMD and 10 patients with QMMD. RESULTS: There were no significant differences in age, sex, family history, and mode of onset between the two groups. Underlying diseases presenting in patients with QMMD were hyperthyroidism (n = 6), neurofibromatosis type 1 (n = 2), Sjögren's syndrome (n = 1), and meningitis (n =1). The RNF213 c.14576G>A mutation was found in 64 patients (84.2%) with MMD and 8 patients (80%) with QMMD; no significant difference in mutation frequency was observed between cohorts. CONCLUSIONS: There are two forms of QMMD, one in which the vascular abnormality is associated with an underlying disease, and the other in which MMD is coincidentally complicated by an unrelated underlying disease. It has been suggested that the presence or absence of the RNF213 c.14576G>A mutation may be useful in distinguishing between these disease types.

Endoscopic third ventriculostomy and cerebrospinal fluid shunting for pure communicating hydrocephalus in children.

PURPOSE: Recent reports regarding endoscopic third ventriculostomy (ETV) for pediatric hydrocephalus revealed that ETV could avoid cerebrospinal fluid (CSF) shunting in certain types of hydrocephalus. However, the effectiveness of ETV for "pure" communicating hydrocephalus that has no obstruction through CSF pathway is still unknown. In this study, we report clinical outcome of ETV and CSF shunting for communicating hydrocephalus and discuss the efficacy of ETV for pure communicating hydrocephalus. METHODS: Children less than 15 years old who underwent ETV or CSF shunting for communicating hydrocephalus were retrospectively reviewed. The absence of obstruction through CSF circulation was confirmed by CT cisternography or cine-contrast image in MRI. RESULTS: Sixty-three patients (45 CSF shunting and 18 ETV) were included. The mean follow-up period was 6.1 years. The success rate was 60% in CSF shunting and 67% in ETV at the last visit (p = 0.867). Normal development was observed in 24 patients (53%) in CSF shunting and 12 patients (67%) in ETV (p = 0.334). There was a significant difference in the mean time to failure (CSF shunting: 51.1 months, ETV 3.6 months, p = 0.004). The factor that affected success rate in ETV was the age at surgery (success 21.6 months, failure 4.4 months, p = 0.024) and ETV success score (success 66.7, failure 50.0, p = 0.047). CONCLUSION: Clinical outcomes of ETV were not inferior to those of CSF shunting in patients with communicating hydrocephalus. Further studies is required to elucidate to establish the consensus of ETV as a treatment option for communicating hydrocephalus.

Infantile intraorbital Ewing's sarcoma: case report and review of the literature.

We reported a 7-month-old female with intraorbital Ewing's sarcoma. Infantile Ewing's sarcoma is rare and its prognosis is poor. Ewing's sarcoma of orbital origin is even rare. There has been only 1 case of infantile intraorbital Ewing's sarcoma reported, and only 5 infantile primary orbital ESFTs (Ewing's sarcoma family of tumors) have been reported. Among these 5 cases, 2 infants who did not receive multimodal therapy died, whereas 3 who received multimodal therapy demonstrated long-term survival. The present case was also treated with multimodal therapy consisting of surgery, chemotherapy, and proton beam radiotherapy. There is no recurrence at 15 months follow-up. No specific treatment strategies have been established yet, and accumulation of cases is necessary. Ewing's sarcoma should be included in the differential diagnosis of infantile intraorbital tumors.

Radiologically occult cervical intradural dermal sinus tract: a case report and review of literature.

We report the unusual case of a 7-month-old girl presenting with congenital cervical dermal sinus tract in which the intradural tract was not detected on preoperative imaging and was identified intraoperatively. Considering possible devastating sequelae of infection, excision of dermal sinus tract might be justified even in the case with radiologically undetected intradural tract.

Surgical outcomes by sectioning a filum terminale in patients with terminal syringomyelia.

BACKGROUND: Although terminal syringomyelia suggests a tethered spinal cord, a consensus has still not been established for surgical indications, when there are no associated abnormalities or only minor associated abnormalities. We analyzed surgical outcomes of sectioning a filum terminale in patients with terminal syringomyelia to elucidate the significance of untethering surgery. METHODS: Fifty-seven pediatric patients with terminal syringomyelia who underwent untethering via sectioning the filum terminale between 2007 and 2018 were retrospectively analyzed. Postoperative outcomes of symptoms and MRI findings were evaluated. RESULTS: Of 57 patients, 40 had other associated abnormalities (25 with filar lipoma and 29 with low conus medullaris) that could be responsible for tethered cord. Nineteen patients had symptoms. The mean age at the time of surgery was 18 months (3-96 months). The mean follow-up period was 3.3 years (1-9 years). Preoperative symptoms improved in 9 patients (47%) after surgery. At 1 year after the surgery, the size of syringomyelia decreased in 19 (33%), increased in 4 (8%), and did not change in 34 (69%) patients. Of 28 patients who were followed up for more than 3 years, the size decreased in 17 (61%), increased in 1 (4%), and did not change in 10 (35%). CONCLUSION: When untethering was performed by sectioning a filum terminale, the size of terminal syringomyelia decreased in more than half of patients in the long term. Sectioning the filum terminale demonstrated the possibility of radiological and clinical improvement in patients with terminal syringomyelia.

Risk factors for ischemic complications in vascular reconstructive surgeries.

OBJECTIVE: There have been reports on postoperative ischemic complications with vascular reconstructive surgery. However, various factors, such as lesions, operative technique, and perioperative treatment, prevent analyzing the causes of ischemic complications in vascular reconstruction surgeries. In the present study, we analyzed the cause of ischemic complications for vascular reconstruction surgeries with the same operator, surgical procedure, and perioperative treatment and without focusing on the lesions. PATIENTS AND METHODS: We retrospectively reviewed 66 patients, including 24 aneurysm cases and 42 ischemic disease cases, between 2008 and 2018. The patient group comprised 35 males and 31 females, and the patient mean age was 63.3 (23-87) years. We investigated the postoperative presence of symptomatic and asymptomatic cerebral ischemia on MRIDWI performed within 4 postoperative days. We conducted a statistical analysis of the ischemic complications and clinical and treatment factors. RESULTS: Symptomatic cerebral ischemia was detected in 3 cases, whereas asymptomatic ischemic findings were identified in 8 cases. All cases of symptomatic cerebral ischemia involved cerebral aneurysms. Results of a univariate analysis revealed an association between symptomatic cerebral ischemia and preoperative antithrombotic therapy (OR, 0.07; p =  0.049 (95 %CI; 0.007-0.8794)), clipping (OR, 4.8; p =  0.0501 (95 %CI; 1.641-342.9)), and aneurysm (OR, 14.16; p =  0.0423 (95 %CI; 0.6991-286.9)). Significant associations were found between asymptomatic cerebral ischemia and preoperative antithrombotic therapy [OR, 0.2941; p =  0.0514 (95 %CI; 0.08335-1.038)], aneurysms [OR, 7.8; p =  0.0146 (95 %CI; 1.414-43.04)] and radial artery grafts (RAGs) [OR, 6.8; p =  0.0192 (95 %CI; 1.410-32.98)]. Multivariate analysis identified clipping [OR, 5.462; p =  0.045 (95 %CI; 1.01-78.25] and preoperative antithrombotic therapy [OR, 0.187; p =  0.037 (95 %CI; 0.004-0.813)] as the risk factors for symptomatic cerebral ischemia. Further, a correlation was found between asymptomatic cerebral ischemia and RAGs [OR, 9.244; p =  0.00013 (95 %CI; 2.34-29.44)]. CONCLUSION: Ischemic complications associated with combined vascular reconstruction surgeries for cerebral aneurysms are possibly associated with procedures related to aneurysmal occlusions. Thus, vascular reconstruction surgeries can be performed relatively safely. Further, preoperative antithrombotic treatment should be considered, and caution is required for asymptomatic cerebral ischemia in RAG cases.

Neoadjuvant chemotherapy for atypical teratoid rhabdoid tumors (AT/RTs).

PURPOSE: Atypical teratoid rhabdoid tumor (AT/RT) is a rare, clinically highly malignant tumor. The extent of the surgical resection may affect survival. However, it is often difficult to perform gross total resection (GTR) at an initial surgery because of the large tumor size and high vascularity. Neoadjuvant chemotherapy may reduce not only the size but also the vascularity. We report our experience, review the literature, and analyze its effectiveness. METHODS: A retrospective chart review of patients who underwent neoadjuvant chemotherapy and second-look surgery was performed. Demographic data, treatment courses, changes in tumor after the chemotherapy, extent of resection and estimated blood loss (EBL) during the second-look surgery, and outcome of each children were evaluated. RESULTS: There are 4 cases. The average age at diagnosis was 13.3 months (2-30 months). Two to 4 courses of neoadjuvant chemotherapy were performed. MRI after the chemotherapy showed reduction of tumor volume, and tumor vascularity at the second-look surgery decreased in all cases. GTR was achieved in 3 cases, and NTR in 1 case. The mean EBL/estimated blood volume (EBL/EBV) was 21.3% (1.5-39%). The mean follow-up period was 23 months (2-48 months). At the last follow-up, 2 patients were alive without recurrence of the tumor (the follow-up periods were 48 and 16 months). CONCLUSIONS: Neoadjuvant chemotherapy for AT/RTs might reduce both tumor size and vascularity, which enabled the maximal tumor resection. It may contribute to improve the prognosis of AT/RT through facilitating the tumor resection.

Second Free Flap Surgery for Skull Base Tumors: Case Report and Literature Review.

Tumors of the skull base, such as meningiomas, tend to recur. With progress in free vascularized flap surgery, an increasing number of studies are investigating skull base reconstruction with free flaps after tumor removal. In this report, we discuss the results of second free flap surgery after skull base reconstructive surgery. We retrospectively analyzed data from patients treated at our center during the period from 2013 through 2017. All four patients identified had skull base anaplastic meningioma and had undergone radiotherapy. In all cases, the flap and donor blood vessel were sourced from sites that differed from those used in the previous surgeries. No complications developed, such as cerebrospinal fluid leakage, meningitis, wound infection, wound hemorrhage, or flap necrosis. Because the first flap was found to be unviable, it was difficult to preserve and was removed. Essential points in preventing complications are anchoring at the appropriate site, pinprick testing of the created flap, and use of multilayered countermeasures to prevent cerebrospinal fluid leakage.

Pediatric nodular fasciitis at the roof of the optic canal causing decreased vision: case report and review of the literature.

We present a 3-year-old girl with decreased visual acuity of the left eye. Radiological studies revealed a mass lesion at the roof of the left optic canal with bony erosion, which compressed the left optic nerve. Gross total resection of the mass and decompression of the optic canal were performed. Histopathological study was consistent with nodular fasciitis. This is the first report of nodular fasciitis at the roof of the optic canal in a young child. Nodular fasciitis compressing the optic nerve should be included in differential diagnoses of optic neuropathy in young children.