Intradiploic arachnoid cyst with extensive deformation of craniofacial osseous structures: case report

OBJECTIVE AND IMPORTANCE: A unique case of a large intradiploic arachnoid cyst involving craniofacial osseous structures is reported. CLINICAL PRESENTATION: The patient presented with a hard mass in the right frontal region, proptosis, and inferior globe displacement. Computed tomography revealed an intraosseous cyst of cerebrospinal fluid intensity with extension from the anterior cranial fossa to the infratemporal fossa. INTERVENTION: After resection of the cyst wall and closure of two small round dural defects, the involved craniofacial region was reconstructed. CONCLUSION: The medical history of the patient and the intraoperative observations support the contention that the cyst in the reported case was congenital in origin. The features concerned with diagnosis and pathogenesis of this rare entity are discussed.     

Spinal hydatid cyst mimicking arachnoid cyst on magnetic resonance imaging

BACKGROUND: Primary spinal hydatid cysts are uncommon and account for 1% of all cases of hydatid disease. Echinococcus granulosus is most often responsible for the cyst hydatid. Intradural, extramedullary involvement is rare. When the cysts do not demonstrate typical magnetic resonance imaging findings, the differential diagnosis is more complex. METHOD: Case report. FINDINGS: An isolated primary hydatid cyst of the spine in a 35-year-old man that appeared to be an arachnoid cyst on preoperative radiographic examination. CONCLUSION: Hydatid cysts that lack the typical radiographic appearance may be mistaken for arachnoid cysts. Misdiagnosis has serious implications for surgical intervention and long-term care.     

Cine-mode magnetic resonance imaging of a thoracic intradural arachnoid cyst: Case report

We report the appearance of a thoracic intradural arachnoid cyst on cine-mode magnetic resonance imaging (MRI). Based on the operative findings, cine-mode MRI was more sensitive for identifying the intradural location of arachnoid cysts than was conventional MRI. The value of cine-mode MRI in diagnosing this rare entity is discussed.     

Growth of occult arteriovenous malformation after cerebral hemorrhage demonstrated by serial magnetic resonance imaging--case report

A 19-year-old male presented with sudden onset of right hemiparesis caused by left cerebral hemorrhage. Cerebral angiography demonstrated no vascular abnormality, and the hematoma was removed surgically. At operation, no abnormal vascular lesion was found in the brain adjoining the hematoma. Two years later, magnetic resonance (MR) imaging demonstrated a few foci of flow voids adjacent to the hematoma cavity. Four years after the hemorrhage, MR imaging showed more extensive flow-void abnormalities that indicated growth of an occult arteriovenous malformation (AVM). Cerebral angiography indicated a definite AVM supplied mainly by branches of the middle cerebral artery. Total resection of this lesion was performed. The histological diagnosis was typical AVM. Immunohistochemistry with vascular endothelial growth factor showed staining in the walls of the abnormal vessels. Serial MR imaging is very useful for the diagnosis and management of occult AVMs.     

Brain abscess and glioblastoma identified by combined proton magnetic resonance spectroscopy and diffusion-weighted magnetic resonance imaging--two case reports

The differential diagnosis between brain abscesses and necrotic tumors such as glioblastomas is sometimes difficult to establish by conventional computed tomography and magnetic resonance imaging. Combined proton magnetic resonance spectroscopy (1H-MRS) and diffusion-weighted magnetic resonance imaging (DWI) were used to establish the preoperative diagnosis of brain abscess and glioblastoma. DWI visualized the brain abscess as a homogeneous hyperintense lesion and 1H-MRS revealed the presence of acetate, lactate, and amino acids and the absence of the normal brain components. DWI sometimes shows glioblastoma as a hyperintense lesion, but 1H-MRS reveals markedly increased lactate and decreased N-acetyl-aspartate. Combined DWI and 1H-MRS findings can distinguish brain abscess and glioblastoma.     

Pineal region metastasis appearing as hypointensity on T2-weighted magnetic resonance imaging--case report

A 48-year-old female presented with headache and limitation of upward gaze. She had a history of total gastrectomy for gastric adenocarcinoma 2 years previously. Computed tomography with contrast medium and T1-weighted magnetic resonance (MR) imaging with gadolinium showed ring-like enhancement of a solitary mass in the pineal region with obstructive hydrocephalus. T2-weighted MR imaging showed the tumor as hypointense. This MR imaging finding complicated the preoperative diagnosis, but malignancy was suspected from the medical history. The tumor was subtotally resected via the occipital transtentorial approach with a rigid endoscope. Histological examination of the surgical specimen revealed adenocarcinoma cells with extensive coagulation necrosis, which might have contributed to the hypointensity on T2-weighted MR imaging. Correct diagnosis of metastatic adenocarcinoma based only on MR imaging may be difficult in such cases, but metastatic adenocarcinoma of the pineal region must be considered in the differential diagnosis of pineal tumors.     

Minute glioma identified by 3.0 Tesla magnetic resonance spectroscopy--case report

A 33-year-old man presented with a minute tumor incidentally detected by magnetic resonance (MR) imaging screening. 1.5 Tesla MR spectroscopy indicated normal brain tissue whereas 3.0 Tesla MR spectroscopy indicated neoplasm. The tumor was completely resected. The histological diagnosis was fibrillary astrocytoma. Minute glioma, measuring less than 15 mm in diameter on MR imaging, can be completely resected, resulting in a good prognosis. 3.0 Tesla MR spectroscopy can establish the diagnosis in the early stage of glioma.     

Spinal cord herniation associated with an intradural spinal arachnoid cyst diagnosed by magnetic resonance imaging

Two rare cases of spinal cord herniation associated with intradural spinal arachnoid cyst are reported. A preoperative magnetic resonance imaging scan demonstrated the presence of spinal cord herniation, identified as a protrusion continuous with the spinal cord. Surgery upon the intradural spinal arachnoid cyst improved progressive neurological dysfunction. The authors postulate that spinal cord herniation occurred for the following reason: The pressure of the intradural arachnoid cyst on the dorsal aspect of the spinal cord caused thinning of the dura, leading to a tear and, thus, the development of an extradural arachnoid cyst. Along with the enlargement of intradural arachnoid cyst, the spinal cord herniated through the tear in the dura into the extradural arachnoid cyst.     

Extra dural arachnoid cyst: case report

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal, which may communicate with the subarachnoid space. Usually located in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report a case of an extradural thoracic arachnoid cyst revealed by progressive spinal cord compression. CT myelography and MRI enabled diagnosis. Rapid neurological improvement was observed after surgical resection.     

Symptomatic intrasellar arachnoid cyst: case report

A case of a large symptomatic intrasellar arachnoid cyst with suprasellar extension is reported. A 53-year-old man was admitted because of decreased visual acuity. Magnetic resonance imaging showed a large intrasellar cyst extending into the suprasellar cistern, with compression of optic nerves. The intensity of the cyst was identical to that of the surrounding subarachnoid space on both T1-, T2-, and proton density-weighted images. Transsphenoidal surgery was performed, but subsequent refilling of the cyst required additional transcranial surgery. Analysis of the cerebrospinal fluid-like cystic fluid revealed high levels of protein and pituitary hormones. Histological study revealed that the cyst wall was composed of connective tissue and arachnoid cells, which were ultrastructurally characterized by a number of desmosomes. Diagnostic, surgical, and pathological features of intrasellar arachnoid cysts are discussed.     

Asymptomatic huge congenital arachnoid cyst successfully treated by endoscopic surgery--case report

A female neonate was the first child of a 30-year-old mother, with unremarkable medical history. Prenatal ultrasonography performed at 36 weeks of gestation suggested intracranial mass lesion. The baby was delivered by cesarean section at 41 weeks of gestation because of bradycardia and asphyxia. The birth weight, height, and head circumference were within the normal ranges with soft fontanels. Congenital anomaly was not observed with normal neurological findings. She was referred to our department at age 5 months. Physical examination revealed normal developmental milestones and intact endocrinological function without macrocephaly. Cerebral magnetic resonance (MR) imaging revealed a unilocular huge cyst appearing as homogeneously hypointense on T(1)- and hyperintense on T(2)-weighted images, and extending into the basal, suprasellar, ambient, quadrigeminal, interpeduncular, prepontine, right cerebellopontine angle, and premedullary cisterns. The pituitary stalk was markedly stretched and displaced ventrally, and the brainstem was displaced dorsally by the cyst. No other brain anomalies, dysgenesis of the corpus callosum, or ventriculomegaly were recognized. Neuroendoscopic cystocisternostomy was performed to form a communication between the cyst cavity and premedullary cistern. Pressurized watery fluid was released on puncturing the cyst wall which consisted of transparent membrane. Surveillance MR imaging at 2 and 9 months after the surgery revealed remarkable regression without regrowth of the cyst. She remained in good condition and showed normal development during the follow up for 1 year 9 months. Less invasive prophylactic surgery using the neuroendoscope may be beneficial for carefully selected cases of asymptomatic neonatal arachnoid cysts.     

Magnetic resonance imaging of a spinal extradural arachnoid cyst

A case of extradural arachnoid cyst in the spinal canal of a 16-year-old male was diagnosed by magnetic resonance imaging. The diagnosis was verified by a metrizamide-enhanced computed tomographic myelogram. An operation with a favorable outcome followed. The noninvasive advantages of magnetic resonance imaging in such a diagnosis are demonstrated by this case.     

Bilocular pericardial cyst diagnosed by magnetic resonance imaging: a case report]

A 47-year-old female who had removal of pericardial cyst is reported. Preoperative examination including echocardiography, computed tomography and magnetic resonance imaging (MRI) demonstrated the cystic nature of the mass attaching to the right pericardial surface. MRI clearly revealed that the cyst was bilocular. MRI brings a more detailed information of pericardial cyst for surgery.     

Postsurgical arachnoid cyst: report of two cases

We present two cases that demonstrate the occurrence of symptomatic arachnoid cysts after craniotomy. Both patients presented 1 year postoperatively with generalized seizures as the only symptom. Focal or localizing neurological signs were not present. Both patients responded well to shunting procedures.     

Giant cervicothoracic extradural arachnoid cyst: case report

The pathogenesis, etiology, and treatment of the spinal arachnoid cyst have not been well established because of its rarity. A 57-year-old male was presented with spastic quadriparesis predominantly on the left side. His radiological examination showed widening of the cervical spinal canal and left neural foramina due to a cerebrospinal fluid - filled extradural cyst that extended from C2 to T2 level. The cyst was located left anterolaterally, compressing the spinal cord. Through a C4–T2 laminotomy, the cyst was excised totally and the dural defect was repaired. Several features of the reported case, such as cyst size, location, and clinical features make it extremely unusual. The case is discussed in light of the relevant literature.

     

Intracranial mucocele mimicking arachnoid cyst: case report

We describe a patient presenting with adult onset seizures whose computed tomographic scan was highly suggestive of arachnoid cyst. The cyst was removed by craniotomy and was found to be a mucocele on histological examination. During operation, no connection to the frontal sinus had been found. The very unusual combination of findings and their clinical implications are discussed.