Giant intradiploic epidermoid cyst of the occipital bone

A rare case of giant intradiploic epidermoid cyst of the occipital bone with large intracranial extension in the posterior fossa is described. The lesion was discovered when the patient presented with headache and subcutaneous swelling in the occipital region, in the absence of signs of neurological involvement. CT scan showed extensive destruction of the occipital bone, mainly of the inner table, up to the foramen magnum. On MRI the lesion was hypointense in T(1) and hyperintense in T(2)-weighted images; signal inhomogeneity was due to cellular debris and cholesterol crystals. The enhancing rim due to the thickened dura confirmed the extradural location. Complete removal of the cyst was easily accomplished despite its large size. We found only 3 documented cases in the literature of giant intradiploic infratentorial epidermoid cysts, none of which was studied by MRI. The radiological features and differential diagnosis are discussed.     

Giant intradiploic epidermoid cyst of the occipital bone

Epidermoid cysts are uncommon, benign and slow-growing lesions. They often reach an enormous size without producing neurologic symptoms. We describe a 35-year-old female who had a giant intradiploic epidermoid cyst of the occipital bone. She underwent posterior cranial fossa tumor resection. Pathology confirmed epidermoid cyst. There was no recurrence at 13-month follow-up. Total removal of these cysts and repeated washing of the cavity with 0.9% saline may prevent recurrence and aseptic meningitis.     

Posttraumatic intradiploic arachnoid cyst of the posterior fossa

We report the case of a 5-year-old girl with an enlarging suboccipital mass, a posttraumatic intraosseous arachnoid cyst. Diagnostic work-up revealed that the lesion consisted of an intradiploic arachnoid cyst and an extra-axial occipital pouch that communicated by way of an osseous and dural defect. Surgical repair was undertaken with good results. A search of the current literature has shown only seven previous reports of leptomeningeal cysts situated at the occipital bones, most of them the result of an antecedent skull fracture. A pathogenetic hypothesis is presented comparing the growth of arachnoid intraosseous cysts and the development of meningocencephaloceles. Received: 1 October 1996     

Post-traumatic intradiploic leptomeningeal fistula and cyst.

A 59 year old female patient presented with ataxia and difficulty in walking. The neurological examination revealed right homonymous hemianopia and ataxia. Radiographic evaluation revealed a large occipital intradiploic cyst mainly in the left suboccipital area. There was also moderate hydrocephalus and encephalomalacia of the left occipital pole. Bone window studies also demonstrated a growing fracture extending from the upper pole of the cyst to the vertex. Both pathologies were attributed to child abuse the patient suffered when she was a child. At first surgery, decompression of the cerebellum was followed by duroplasty and acrylic cranioplasty to the posterior cranial fossa. A month later, a shunt had to be inserted for hydrocephalus. At 7 months postoperatively, the patient is well and free of any symptoms or recurrence.     

颅骨板障内蛛网膜囊肿2例报告及文献复习

目的探讨颅骨板障内蛛网膜囊肿的临床特点、诊治方法。方法对收治的2例颅骨板障内蛛网膜囊肿患者的临床资料及相关文献进行回顾性分析。结果颅骨板障内蛛网膜囊肿患者以枕部为好发部位,常见临床表现为局灶性不适和疼痛,CT检查显示颅骨板障内膨胀性溶骨性改变。结论颅骨内板和硬脑膜缺损是导致颅骨板障内蛛网膜囊肿形成的重要因素,手术治疗是安全有效的方法。     

Treatment of a Traumatic Leptomeningeal Cyst in an Adult with Fibrinogen-Based Collagen

Reports of traumatic leptomeningeal cysts (TLMC) are rare in adults. The standard treatment approach is craniectomy with careful exposure of the intact dural edges, followed by duroplasty. However, occasionally, the location of the TLMC makes achieving watertight duroplasty impossible. Herein, we report the case of a 28-year-old male who presented with a soft growing mass on the vertex of his head 16 months after the head trauma. Upon enhanced CT examination, a bony defect involving both the inner and outer table of the cranium was observed close to the sagittal sinus, and a well-defined cystic mass, 5 cm in diameter, was nested within the defect. The risks associated with extension craniotomy were high because the lesion was located superficial to the sagittal sinus, we opted to use fibrinogen-based collagen fleece (TachoCombR®) to repair the dural defect. Two months after surgery, the patient remained asymptomatic with a good cosmetic result. In cases like ours, when the defect is near the major sinuses and the risk of rupturing the sinus during watertight dural closure is high, fibrinogen-based collagen fleece (TachoComb®) is an effective alternative approach to standard dural suture techniques.     

Posttraumatic Giant Extradural Intradiploic Epidermoid Cysts of Posterior Cranial Fossa : Case Report and Review of the Literature

We reported a unique case of posttraumatic giant infratentorial extradural intradiploic epidermoid cyst. A 54-year-old male, with a previous history of an open scalp injury and underlying linear skull fracture in the left occipital region in childhood, presented with a painful subcutaneous swelling, which had been developed gradually in the same region and moderate headache, nausea, vomiting and cerebellar ataxia. The duration of symptoms on admission was 3 months. Imaging studies revealed occipital bone destruction and giant extradural intradiploic lesion. The preoperative diagnosis was giant infratentorial extradural intradiploic epidermoid cyst. Surgery achieved total removal of the lesion, which was histologically confirmed and the postoperative course was uneventful. To our knowledge, this is the first case of giant infratentorial extradural intradiploic epidermoid cyst with a traumatic etiology described in the literature.     

Occipital encephalocele

The brain from an infant with a cystic occipital mass present at birth is examined in serial section. The occipital mass proved to be a rhombic roof ventriculocele. Within the posterior fossa, it was bound to an occipital lobe encephalocele which issued as a diverticulum of the left lateral ventricle through a microgyric cortical defect in the territory of the left posterior cerebral artery. The posterior medial aspects of both cerebral hemispheres were herniated downward into the widened tentorial gap. Craniolacunae were prominent on the inner aspect of the skull. The aqueduct and central canal of the spinal cord were widely dilated, although the lateral ventricles were collapsed. It is suggested that hydrocephalus secondary to obstruction to flow of CSF through the rhombic roof entrained a sequence of events giving rise to the rhombic roof ventriculocele and causing occlusion of the posterior cerebral artery and subsequent diverticulation of the lateral ventricle through an infarcted region of the posterior-medial hemisphere.     

Dandy-Walker cyst associated with occipital meningocele

Dandy-Walker cyst associated with occipital meningocele is very rare. Only 12 patients have been reported. We report a female infant with Dandy-Walker cyst and occipital meningocele whose diagnosis was suspected antenatally by in utero ultrasonography. At birth, head circumference was normal for 37 weeks gestation. She underwent surgical repair of the occipital meningocele immediately after birth. The post-operative course was uneventful until the sixth day of life when progressive enlargement of the head with progressive ventricular dilatation was recognized. Communication between the posterior fossa cyst and the occipital meningocele was confirmed neuroradiologically; the occipital meningocele may have compensated for the increased intracranial pressure in fetal life.     

Giant intradiploic infratentorial epidermoid cyst

Epidermoid cysts are benign, uncommon lesions (1% of all intracranial tumors). Their localization is intradiploic in 25% of cases, and exceptionally subtentorial. We report here a rare case of giant intradiploic infratentorial epidermoid cyst. A 74-year old patient presented with recent diplopia and sindrome cerebellar. CT scan and MR imaging revealed a giant osteolytic extradural lesion of the posterior fossa (5.2 cm x 3.8 cm) with a small area of peripheral enhancement after contrast injection. Retrosigmoid suboccipital craniectomy allowed a satisfactory removal of the tumor, followed by an acrylic cranioplasty. The outcome was good. Neuropathological examination confirmed an epidermoid cyst. We review the literature and discuss our case.     

Posterior fossa cysts: clinical,neuroradiological and surgical features

Various types of neuroimaging investigations were performed in 26 patients with posterior fossa cysts. The results were retrospectively analyzed to facilitate differential diagnosis and clarify indications for surgery. Four major findings were obtained in this study. First, posterior fossa intra-arachnoid cysts were encountered more frequently than expected and were found to be surgically treatable. Second, although IV ventricular cysts were categorized as Dandy-Walker malformation, Dandy-Walker variant, and persistent Blake's pouch in this study, the distinctions of neuroimaging findings between these three types are uncertain. Third, the diagnostic criteria for mega cisterna magna were established, and it was found be be a surgically untreatable condition. Finally, in cases with the following neuroimaging findings, surgery appears to be indicated: (1) occipital bossing or petrosal scalloping with distortion or obliteration of cerebrospinal fluid (CSF) cisterns of the posterior fossa; (2) compression and deformity of the brain surrounding the cyst; (3) radioisotope and/or computed tomography cisternographic findings suggestive of disturbance of intracystic CSF circulation; (4) a non-communicating cyst.     

Evaluation of Non-Watertight Dural Reconstruction with Collagen Matrix Onlay Graft in Posterior Fossa Surgery

Objective

Many surgeons advocate for watertight dural reconstruction after posterior fossa surgery given the significant risk of cerebrospinal fluid (CSF) leak. Little evidence exists for posterior fossa dural reconstruction utilizing monolayer collagen matrix onlay graft in a non-watertight fashion. Our objective was to report the results of using collagen matrix in a non-watertight fashion for posterior fossa dural reconstruction.

Methods

We conducted a retrospective review of operations performed by the senior author from 2004–2011 identified collagen matrix (DuraGen) use in 84 posterior fossa operations. Wound complications such as CSF leak, infection, pseudomeningocele, and aseptic meningitis were noted. Fisher''s exact test was performed to assess risk factor association with specific complications.

Results

Incisional CSF leak rate was 8.3% and non-incisional CSF leak rate was 3.6%. Incidence of aseptic meningitis was 7.1% and all cases resolved with steroids alone. Incidence of palpable and symptomatic pseudomeningocele in follow-up was 10.7% and 3.6% respectively. Postoperative infection rate was 4.8%. Previous surgery was associated with pseudomeningocele development (p<0.05).

Conclusion

When primary dural closure after posterior fossa surgery is undesirable or not feasible, non-watertight dural reconstruction with collagen matrix resulted in incisional CSF leak in 8.3%. Incidence of pseudomeningocele, aseptic meningitis, and wound infection were within acceptable range. Data from this study may be used to compare alternative methods of dural reconstruction in posterior fossa surgery.     

A Ruptured Dermoid Cyst of the Cavernous Sinus Extending into the Posterior Fossa

Supratentorial dermoid cysts are uncommon to develop in the cavernous sinus. We present a ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa. The patient was a 32-year-old female who complained occipital headache, blurred vision, and tinnitus over 4 years. Brain magnetic resonance (MR) imaging revealed an enhanced tumor in the right cavernous sinus extending into the right temporal base and the posterior fossa with findings of ruptured cyst. Surgical resection was performed, and pathological findings were confirmed to be a dermoid cyst. We report a second case with ruptured dermoid cyst of the cavernous sinus extending into the posterior fossa.     

Chronic intradiploic hematoma in patients with coagulopathy

Intradiploic hematomas occur rarely. They have been reported in patients with and without coagulation disorders. The presentation of intradiploic hematomas varies depending on their location and the severity of the coagulopathy. We describe a patient with a huge hemicranial chronic intradiploic hematoma. Surgery involved opening the thinned outer table and evacuation of a jelly-like material and an organized clot, leaving behind the inner table. The rarity of this disease, possible pathogenesis and related surgical aspects are discussed.     

Ultrastructure of the wall of the Dandy-Walker cyst

Summary The ultrastructure of the wall of the Dandy-Walker cyst has been described rarely. A boy aged 2 years was confirmed clinically, neuroradiologically, and operatively as having a Dandy-Walker cyst in the posterior fossa. The cyst wall obtained during surgery consisted of an outer arachnoid cell layer, intermediate interwoven neuroglial strands, and an inner layer of cells which lacked the characteristic appearance of ependyma. An unusual finding was a small, buried island of ependymal cells in the intermediate layer of the neuroglial tissue. Ultrastructural study of the cyst wall provides a better understanding of the pathogenesis of the Dandy-Walker syndrome.     

Cerebrospinal fluid (CSF) leak and pseudomeningocele formation after posterior fossa tumor resection in children: a retrospective analysis

Objective The purpose of this study was to determine the incidence of pseudomeningocele and cerebrospinal fluid (CSF) leak after posterior fossa tumor surgery and to analyze factors that may be associated with these conditions. In particular, we wished to determine if there was evidence to support the hypothesis that the use of tissue glue, dural grafts, or external ventricular drainage (EVD) prevented CSF from leaking outside the closed dura. Materials and methods A retrospective chart review was carried out of posterior fossa tumor resections at British Columbia’s Children’s Hospital. Information was collected regarding tumor location, surgical approach, CSF diversion, dural grafting, and use of tissue glue. Multiple univariate analyses and step-wise logistic regression were performed to identify factors associated with pseudomeningocele formation or CSF leak. A pseudomeningocele was said to be present if it was noted in the clinical records or if a fluid collection was present superficial to the craniotomy flap on a postoperative CT or MR scan. Results Out of 174 posterior fossa operations, 53 pseudomeningoceles with or without CSF leak were identified along with five CSF leaks in the absence of pseudomeningocele (33%). None of the factors examined reached statistical significance, although there was a trend towards higher rates in patients with external CSF drainage (P=0.06631), dural graft usage (p=0.06492), and patients in whom tissue glue was used (p=0.06181). On logistic regression, only tissue glue use and external CSF drainage were associated with increased incidence of pseudomeningocele and/or CSF leak. Conclusion In this retrospective study, the use of tissue glue, dural grafts, and external ventricular drainage was not associated with a reduced rate of clinically or radiologically diagnosed pseudomeningocele formation or postoperative CSF leak. The results of this study provide a basis for planning a randomized controlled trial to determine the effectiveness of tissue glue and/or dural grafting in preventing these complications. A commentary on this paper is available at .     

Sphenoidal meningoencephalocele associated with CSF fistula and arteriovenous malformation Spetzler-Martin V: A case report

Cerebral Arteriovenous malformations (AVMs) are presumed congenital anomalies of the blood vessels, which can increase intracranial pressure by uncertain mechanisms.We report the rare case of a 55-year-old male patient who complained about CSF rhinorrhea. Persisting CSF leakage prompted CT, which evidenced a bone defect in the right middle cranial fossa with protruding brain tissue. The diagnosis of a sphenoidal meningoencephalocele was made. Neuroimaging evidenced an AVM Spetzler Martin V. The lesion was targeted via an endonasal approach with resection of the herniated brain tissue and closure of the bony and dural defects. The postoperative course was uneventful without recurrence of the CSF fistula.Documentation of these cases is essential to come up with standardized therapeutical protocols and follow-up. Nevertheless, conservative management of the AVM and surgical repair of the bone defects is an appropriate approach in the first instance, depending on the morphology and characterization of the AVM.     

Transcranial cerebellar herniation following craniotomy: Case report and literature review

To report a case of post-surgical encephalocele through craniotomy burr holes following the resection of a meningioma of the posterior fossa. A 49-year-old female presented in the emergency room with cephalea. The MRI showed a meningioma of the convexity of the posterior fossa. A resection was performed and the bone flap replaced. The patient recovered uneventfully and was discharged. After 30 days the patient consulted referring cephalea, vomiting and imbalance. Brain MRI revealed a trans-cranial cerebellar herniation through the craniotomy burr holes. An urgent surgery was performed to repair the encephalocele. Post-surgical brain MRI was performed and did not show complications.Post-surgical encephalocele is an uncommon complication after the resection of a posterior fossa lesion. To avoid this complication, it is recommended thorough dural and bony closure, particularly in the posterior fossa surgeries and in high-risk patients.     

Surgical results of posterior fossa decompression for patients with Chiari I malformation

Introduction An increasing number of children with Chiari I malformations are coming to the attention of neurosurgeons today, although a consensus on the surgical approach to these lesions has yet to be found.Methods We present a retrospective analysis of posterior fossa decompression (PFD) performed at our institution on 96 patients from 1989 to 2001. Statistical analyses based on clinical and radiographic presentation and the types of surgical procedures used formed the basis for our review.Results Most of the patients with hydromyelia underwent duraplasty procedures with or without tonsillar manipulation. In contrast, most patients without hydromyelia underwent bony decompression with dural scoring and intraoperative ultrasound. PFD with bony decompression and dural scoring showed a 72% success rate, compared with 68% for duraplasty. Dural opening was not more likely to improve or arrest hydromyelia. The group subjected to duraplasty, however, had a significantly higher complication rate. Patients under the age of 8 fared better than their older counterparts.Conclusions Overall, we favor a tailored posterior fossa craniectomy with dural scoring as the initial surgical procedure in children with Chiari I malformation with or without a syrinx. This less invasive approach minimizes complications associated with dural opening and offers comparable success rates.