(1/80) Rathke's cleft cysts: surgical-MRI correlation in 16 symptomatic cases.

Rathke's cleft cysts (RCCs) are non neoplastic epithelial lesions of the sellar region that have been rarely reported as a clinical entity. We retrospectively reviewed the magnetic resonance imaging (MRI), intraoperative, and pathological findings of a series of 16 cases of RCCs operated at our institution since 1992. Concurrently, we discussed the different hypotheses about their embryological origin. The patients included 12 females and 4 males, 11 to 73 years of age. Endocrine disturbance was the most common presentation, followed by headaches and visual impairment. The location of the cyst was intrasellar in 7 cases, intrasellar and suprasellar in 6 cases, and suprasellar in 3 cases. The size of the cyst ranged from 8 to 26 mm (mean 12 mm). MRI signal intensity was quite variable on T1-weighted images. The cyst appeared hyperintense in 6 cases, hypointense in 6 cases, isointence in 3 cases, and heterogeneous in one case. On T2-weighted images (available in 13 cases), the signal intensity was more constant and appeared hyperintense in 11 cases and hypointense in 2 cases. After Gd-DTPA, we did not observe enhancement either of the cyst contents or of the cyst wall, but only of the pituitary gland in all patient. Most often, the pituitary gland was displaced inferiorly by the cyst located above showing a typical image of "an egg in a cup". Fifteen patients were operated upon via the transsphenoidal approach and one upon a frontal craniotomy. Intraoperatively, the cyst contents were gelatinous or thick, and dark colored. In 2 cases, it was cerebrospinal fluid-like corresponding to the signal observed on MRI. The position of the pituitary gland confirmed by surgery in 15 cases coincided with enhancement seen and MR imaging. In 13 cases where biopsy of the cyst wall was performed, it confirmed focally ciliated columnar or cuboid epithelium. A coexistent adenoma was found in one case. In conclusion, we consider that RCCs have varied MRI characteristics so that no pathognomonic sign may be observed. Except in few cases, there were no correlation between MRI and intraoperative findings. Therefore, even with MRI studies, differential diagnoses with others cystic lesions of the sellar region remains extremely difficult. The most interesting findings on MRI studies of RCCs were to locate the pituitary gland to help the surgeon to preserve pituitary tissue during surgery.  (+info)

(2/80) MR imaging findings of Rathke's cleft cysts: significance of intracystic nodules.

BACKGROUND AND PURPOSE: Rathke's cleft cysts often may be difficult to differentiate from other intrasellar or suprasellar masses on radiologic studies. The purpose of this study was to describe the significance of intracystic nodules, a diagnostic characteristic found in Rathke's cleft cysts, on MR images. METHODS: A retrospective review of MR studies was conducted for 13 patients who, after pathologic analysis, were diagnosed as having Rathke's cleft cyst. These patients underwent unenhanced and contrast-enhanced T1- and T2-weighted axial and coronal spin-echo sequential imaging. The signal intensity and incidence of the intracystic nodules on T1- and T2-weighted images were analyzed. The signal intensity of the nodule was compared with that of white matter and surrounding cyst fluid. The signal intensity of cyst fluid was compared with the intraoperative appearance of the cyst fluid. Biochemical and pathologic analyses of the intracystic nodules were conducted in two cases. RESULTS: An intracystic nodule having high signal intensity on T1-weighted images and low signal intensity on T2-weighted images was observed in 10 (77%) of the cases. At surgery, intracystic nodules were yellow, waxy, solid masses. Pathologic analysis showed this nodule to be a mucin clump. Biochemical analysis of the intracystic nodules showed cholesterol and proteins as the main constituents. In the Rathke's cleft cyst with intracystic nodules, cyst fluid revealed low signal intensity to isointensity relative to the intensity of the nodules on T1-weighted images, and isointensity to high signal intensity on T2-weighted images. Intracystic nodules were clearly visible on T2-weighted images. CONCLUSION: Because cyst fluid of Rathke's cleft cysts shows variable intensities on MR images, the specific diagnosis is often difficult when based on MR signal intensity values alone. The presence of an intracystic nodule with characteristic signal intensities on MR images may be indicative of the diagnosis of Rathke's cleft cyst.  (+info)

(3/80) Colloid cysts of the third ventricle: are MR imaging patterns predictive of difficulty with percutaneous treatment?

BACKGROUND AND PURPOSE: Colloid cysts of the third ventricle are rare benign brain tumors. The purpose of this study was to correlate their patterns on MR images with the probability of success of percutaneous treatment. METHODS: Nineteen patients underwent endoscopic treatment for colloid cysts of the third ventricle. The cases were divided into two groups based on difficulty of the aspiration procedure. We reviewed CT scans and MR images and divided cysts into groups based on their signal intensity on the MR images and their density on CT scans. Intensity and density were correlated with difficulty of aspiration during the endoscopic procedure. RESULTS: The aspiration procedure was difficult in 63% of the cases. Eighty-nine percent of hyperdense cysts on unenhanced axial CT scans were categorized as difficult, and 75% of hypodense cysts were categorized as easy. On T2-weighted MR sequences, 100% of low-signal cyst contents were difficult and nearly 63% of high-signal lesions were easy. There was a significant correlation between the T2-weighted sequences and the CT scans regarding the difficulty of the aspiration procedure. CONCLUSION: T2-weighted MR sequences are useful for predicting difficulty of aspiration during stereotactic or endoscopic procedures. A T2-weighted low-signal cyst is correlated with high-viscosity intracystic contents.  (+info)

(4/80) CSF flow studies of intracranial cysts and cyst-like lesions achieved using reversed fast imaging with steady-state precession MR sequences.

BACKGROUND AND PURPOSE: Differentiating between intracranial cysts or cyst-like structures and communicating or noncommunicating cysts is often not possible with cranial CT or nonfunctional MR imaging. We evaluated a retrospective ECG-gated fast imaging with steady-state precession (PSIF) MR sequence with optional cine mode to differentiate cystic masses from enlarged CSF spaces and to determine the accuracy of detecting communication between cysts and neighboring CSF spaces. METHODS: Fourteen patients with intracranial cystic masses underwent CSF flow studies with an ungated and a retrospective ECG-gated cine-mode PSIF sequence in addition to spin-echo imaging. Findings were evaluated retrospectively by using a five-point rating scale and without knowledge of clinical or other imaging findings. Results were compared with intraoperative findings or with results of intrathecal contrast studies. RESULTS: Eighteen arachnoid cysts and one enlarged cisterna magna were diagnosed. Improved differentiation between cysts and enlarged CSF spaces was obtained with cine-mode PSIF imaging in six lesions (six patients). Increased diagnostic certainty as to communication between cysts and CSF spaces was obtained in 18 cysts (13 patients). Diagnoses were verified by membranectomy in five lesions, by CT cisternography in five lesions, and indirectly by shunting in one cystic lesion. In one case, MR diagnosis was not confirmed by CT cisternography. CONCLUSION: Cine-mode MR imaging with a retrospective ECG-gated flow-sensitive PSIF sequence contributed to the certainty of communication between arachnoid cysts and neighboring CSF spaces with an accuracy of 90%, using surgical findings or intrathecal contrast studies as reference. Differentiation between intracranial cysts and enlargement of CSF spaces and other cystic masses was improved in 25% of cases.  (+info)

(5/80) Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and adrenal insufficiency induced by rathke's cleft cyst: a case report.

We report a case of a seventy-year-old woman with syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and adrenal insufficiency induced by Rathke's cleft cyst. She experienced nausea, vomiting, diarrhea, and headache and disturbance of consciousness induced by hyponatremia at a serum sodium level of 100 mEq/l. In spite of severe hyponatremia, urinary sodium excretion was not suppressed and serum osmolality (270 mOsm/kg) was lower than urine osmolality (304 mOsm/kg), and arginine vasopressin (AVP) remained within normal range. SIADH was diagnosed because she was free from other diseases known to cause hyponatremia such as dehydration, cardiac dysfunction, liver dysfunction, renal dysfunction, hypothyroidism, and adrenal insufficiency. Cranial computed tomographic (CT) scan and cranial magnetic resonance (MR) imaging showed a cystic lesion of approximately 2 cm in diameter in the pituitary gland. These images suggested that the cystic lesion was a Rathke's cleft cyst, which was the cause of SIADH. Water restriction therapy normalized her serum sodium concentration and improved her symptoms. After one year, she suffered from general fatigue, appetite loss, fever, and body weight loss (5 kg/2 months). She had neither hypotension nor hypoglycemia, but her serum sodium level was low and serum cortisol, ACTH, and urine free cortisol were very low. Therefore, secondary adrenal insufficiency was suspected and diagnosed by stimulation tests. After start of hydrocortisone replacement therapy (10 mg/day), her symptoms disappeared. In conclusion, Rathke's cleft cyst should be kept in mind as a potential cause in a patient with SIADH, hypopituitarism, and/or adrenal insufficiency.  (+info)

(6/80) Congenital destructive hemispheric lesions and epilepsy: clinical features and relevance of associated hippocampal atrophy.

We studied the clinical, EEG and MRI findings in 19 patients with epilepsy secondary to congenital destructive hemispheric insults. Patients were divided in two groups: 10 with cystic lesions (group 1), and 9 with atrophic lesions (group 2). Seizure and EEG features, as well as developmental sequelae were similar between the two groups, except for the finding that patients of group 2 more commonly presented seizures with more than one semiological type. MRI showed hyperintense T2 signal extending beyond the lesion in almost all patients of both groups, and it was more diffuse in group 2. Associated hippocampal atrophy (HA) was observed in 70% of group 1 patients and 77.7% of group 2, and it was not correlated with duration of epilepsy or seizure frequency. There was a good concordance between HA and electroclinical localization. The high prevalence of associated HA in both groups suggests a common pathogenesis with the more obvious lesion. Our findings indicate that in some of these patients with extensive destructive lesions, there may be a more circumscribed epileptogenic area, particularly in those with cystic lesions and HA, leading to a potential rationale for effective surgical treatment.  (+info)

(7/80) Tentorial enhancement on MR images is a sign of cavernous sinus involvement in patients with sellar tumors.

BACKGROUND AND PURPOSE: This study was undertaken to analyze enhancement patterns of the dura around sellar tumors and to compare the results with tumor invasion or compression of the cavernous sinuses. Postoperative enhancement patterns on MR images were compared with preoperative findings. METHODS: Contrast-enhanced coronal and sagittal MR images were examined prospectively in 96 patients with sellar tumors (65 macroadenomas, 15 microadenomas, 14 Rathke cleft cysts, and two chordomas at the sella). All patients underwent surgical treatment, and pre- and postsurgical features on MR images were compared. RESULTS: Presurgical MR images showed dural enhancement in 36.5% of the patients: asymmetric tentorial enhancement in 24 patients, symmetric tentorial enhancement in seven, and sphenoidal ridge or clivus enhancement in four. Asymmetric tentorial enhancement disappeared after surgical decompression in seven patients. For evaluation of cavernous sinus invasion ipsilateral to the enhancement, sensitivity and specificity of the asymmetric tentorial enhancement sign were 81.3% and 86.3%, respectively. Sensitivity and specificity of the sign were 42.9% and 93.6% for cavernous sinus involvement, including compression and invasion. CONCLUSION: Asymmetric tentorial enhancement is a useful sign in the diagnosis of invasion or severe compression of the cavernous sinus by sellar tumor. The sign may represent venous congestion or collateral flow in the tentorium due to obstructed flow in the medial portion of the cavernous sinus.  (+info)

(8/80) Intramedullary enterogenous cyst presenting with spastic paraparesis during two consecutive pregnancies: a case report.

A 35 year old woman presented with two episodes of spastic paraparesis, occurring in the third trimester of two consecutive pregnancies. The neurological symptoms seemed to be caused by an intramedullary cyst in the thoracic spinal cord. The cyst was subtotally removed and histopathologically diagnosed as enterogenous cyst. Other congenital abnormalities were absent. The peculiar timing of the clinical manifestation of an intramedullary cyst has not been described before. An unequivocal explanation for this phenomenon is missing, but several factors related to pregnancy that may play a part are discussed.  (+info)