Pneumosinus dilatans of the sphenoid sinus

Four cases of pneumosinus dilatans of the sphenoid sinus are reported, supplementing the eight cases previously reported in the literature. This rare entity is characterized by expansion of a paranasal sinus that contains only air. In one patient, severe visual loss due to compression of the optic canal by the adjacent enlarged sinus was seen. Galactorrhea occurred in one patient, and three of the four patients reported headaches. There was dehiscence of the sinus roof in two cases, which apparently resulted in a cerebrospinal fluid fistula in one. Previous reports of this entity are reviewed, and the radiographic findings and clinical presentations are discussed. It is proposed that the term "pneumosinus dilatans" be used to describe all dilated, air-filled sinuses with outwardly bulging walls when the primary cause is uncertain.     

Pneumosinus dilatans in anterior skull base meningiomas

Introduction

Skull base meningiomas are often missed on non-contrast CT or MR examinations due to their close proximity to bone and low lesion to brain contrast. The purpose of this study is to illustrate that pneumosinus dilatans can be an indicator of anterior skull base meningiomas.

Methods

A retrospective search of the radiology information system and picture archiving and computing system database was performed. Search terms were “meningioma” in association with “pneumosinus dilatans.” Medical records and imaging studies were reviewed independently by two experienced neuroradiologists and were read in consensus. We recorded the patient age at the time of discovery of the meningioma, main presenting symptom(s), location of the tumor, and imaging characteristics. We also performed a comparative literature search for pneumosinus dilatans and its association with meningiomas.

Results

Ten patients (six women; four men) were identified in whom a meningioma of the anterior skull base was associated with a pneumosinus dilatans. Three patients had multiple meningiomas, so a total of 14 intracranial tumors were identified. Mean age at discovery was 59 years with an age range of ±20 years. All meningiomas were diagnosed by MRI and/or CT.

Conclusion

Pneumosinus dilatans can be a helpful sign to indicate the presence of a meningioma of the anterior skull base.     

Retroclival arachnoid cyst.

Retroclival arachnoid cyst is a rare mass lesion, with only seven cases previously reported in literature. MR is the imaging modality of choice in its evaluation and in its differentiation from epidermoid cyst. The case reported here was surgically proved and had an uncharacteristic MR signal intensity that was higher than that of cerebrospinal fluid due to previous hemorrhage.     

An intraventricular arachnoid cyst.

The computed tomographic appearance and the differential diagnosis in a case of unusual congenital intraventricular arachnoid cyst are presented.     

Pneumosinus dilatans and multiplex: report of three rare cases and review of the literature

Pneumosinus dilatans is a term used to describe a localized abnormal dilatation of one or more paranasal sinuses without radiological evidence of localized bone destruction, hyperostosis or mucous membrane thickening. The involvement of all paranasal sinuses and mastoid air cells has been named pneumosinus dilatans multiplex. Although the involvement of one or more paranasal sinuses has been reported widely, all paranasal sinuses and the concomitant involvement of mastoid air cells has been reported in only one case. Herein, we present three unusual cases of pneumosinus dilatans (one is a second case of pneumosinus dilatans multiplex in English literature, another is the first reported case of a frontal pneumosinus dilatans case associated with frontoethmoidal meningocele, mental retardation and facial asymmetry and the third one is pneumosinus dilatans with a huge arachnoid cyst) along with the review of relevant literature.     

Intradural spinal arachnoid cyst. Case report

An intradural spinal arachnoid cyst presenting with spinal cord compression is discussed. This case illustrates the value of magnetic resonance imaging in the diagnosis and follow-up of intradural spinal arachnoid cysts.     

Asymptomatic giant arachnoid cyst

ABSTRACT: A 51-year-old male bricklayer without cerebral symptoms underwent whole-body FDG PET for suspicion of mediastinal sarcoidosis. PET/CT incidentally demonstrated a voluminous right frontal arachnoid cyst with normal glucose metabolism in the adjacent cortex. MRI demonstrated compression of the ipsilateral cerebral parenchyma and precentral, angulate, callosal, and superior frontal sulci. Functional bilateral finger-thumb paradigm MRI revealed right hemispheric reorganization of cortical motor activation with prominent activation between the inferior frontal gyrus and the postcentral gyrus.     

Pneumosinus dilatans of the ethmoid sinus presenting with exophthalmus: a case report and review of the literature

Pneumosinus dilatans (PSD) is a rare condition of unknown aetiology in which there is enlargement of the paranasal sinuses by air, where the affected sinus expands beyond the normal boundaries of bone without thinning of its bony walls. The case of a 28 year old male with PSD, who had gradually increasing exophthalmus and diplopia, is presented and characteristics of this condition are reviewed with literature data.     

Intra- and extracerebral arachnoid cyst. An atypical roentgenographic presentation.

Arachnoid cysts present in a variety of ways, and the preoperative diagnosis usually requires a high degree of suspicion. Bony changes consistent with a chronic focal mass effect, a relative paucity of clinical findings compared to the size of the lesion, and an extracerebral mass with an intracerebral component suggest the possibility. We present a case in which there appears to be a large, deep intracerebral mass associated with an extracerebral expansion.     

Intradiploic arachnoid cyst: case report

Because of the extreme rarity of intradiploic arachnoid cysts, their pathogenesis is unknown; congenital or traumatic origins are suggested. We report an intradiploic arachnoid cyst in a 57-year-old woman, without a history of trauma, in whom a forgotten injury might play a significant role.     

An unusual spinal intradural arachnoid cyst

Spinal intradural arachnoid cysts are seen most frequently in the thoracic region, particularly near the midline posteriorly. A thoracic intradural arachnoid cyst in this typical location is reported, with the additional unusual finding of herniation of the spinal cord through an anterior defect in the dura mater. The MRI findings are described.     

Intracanalicular arachnoid cyst mimicking acoustic neuroma: CT and MRI.

A patient with a surgically proven intracanalicular arachnoid cyst was studied using computed tomography, magnetic resonance imaging, and air CT cisternography. The lesion had a similar radiographic appearance to acoustic neuroma and therefore, although rare, must be considered in the differential diagnosis of intracanalicular mass lesions. We report a case in which examination was performed, in evaluating the lesion, utilizing high-resolution air CT cisternography and magnetic resonance imaging (MRI).     

Association of posttraumatic spinal arachnoid cyst and syringomyelia

A patient developed a painful progressive paraparesis following trauma. Metrizamide myelography revealed an arachnoid cyst. A delayed metrizamide computed tomography scan of the area confirmed the cyst and demonstrated a syrinx at that level that was not appreciated on the myelogram. The association of these two lesions after trauma are perhaps more common than appreciated and the importance of a computed tomography scan of the abnormal area on myelography is emphasized.     

飞行人员颅内蛛网膜囊肿11例报告

我院神经外科自1995～2006年收治颅内蛛网膜囊肿飞行人员11例,采取了不同的治疗方法与鉴定结论.现报告如下：