Rathke cleft cysts: correlation of enhanced MR and surgical findings.

PURPOSETo describe the gadolinium-enhanced MR findings of Rathke cleft cyst correlate them with the surgical findings, and define those preoperative findings that differentiate this lesion from other sellar and juxtasellar tumors.METHODSWe studied 18 patients who were diagnosed as having Rathke cleft cyst pathologically. These patients were imaged with T1- and T2-weighted coronal and sagittal spin-echo sequences. Fifteen of these patients received gadopentetate dimeglumine.RESULTSIn eight patients, the cyst showed low intensity on T1-weighted images and high intensity on T2-weighted images. At surgery, the cyst fluid was cerebrospinal fluid-like or light brown in five patients, motor oil-like in one patient, and milky in two patients. In 10 patients, cysts showed isointensity to high intensity on T1-weighted images and had various intensity on T2-weighted images. All 10 contained milky fluid. In three patients the intensity of fluid was heterogeneous. A waxy nodule was found in two patients. The position of the normal pituitary gland confirmed by surgery in all cases coincided with enhancement on MR imaging. The variable position of the normal pituitary gland was clearly identified in the sagittal images. The cyst walls showed no enhancement by gadopentetate dimeglumine.CONCLUSIONSBecause Rathke cleft cysts show variable intensities on MR, the diagnosis is often difficult when based on MR signal intensity values alone. MR imaging with gadopentetate dimeglumine does assist in the diagnosis of Rathke cleft cysts. Diagnostic clues include the lack of cyst wall enhancement and displacement of the normal pituitary gland.     

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.     

MR appearance and cyst content of Rathke cleft cysts

The magnetic resonance signal intensity and cyst content were analyzed in 2 new and 17 previously reported cases of Rathke cleft cyst. Lesions displaying hypointensity on T1-weighted images (T1WI) and hyperintensity on T2-weighted images (T2WI) contained CSF-like fluid. Cases showing hyperintensity on T1WI and isointensity on T2WI frequently contained mucoid material. Hyperintensity on both T1WI and T2WI suggests the presence of blood. A small area of hypo- or isointensity indicates thickening of the cyst wall or collection of cellular debris.     

Rathke囊肿囊内结节的MRI表现及诊断价值

目的：研究Rathke囊肿的囊内结节MRI表现特点及意义。方法：回顾性分析27例经手术病理证实的Rathke囊肿的MRI表现,观察囊内结节的发生率、大小、信号特点及有无强化。其中男11例,女16例,平均年龄33.4岁。所有患者均行MRI平扫及增强扫描。结果：10例Rathke囊肿内出现结节,T1WI表现为高、等或稍低信号,T2WI表现为低信号。结节大小为0.3-1.1 cm,平均0.6 cm。增强扫描囊内结节无强化。结论：鞍区囊性占位内出现囊内结节,显示特征性信号并且无强化,有助于Rathke囊肿的诊断。     

Parapharyngeal second branchial cyst manifesting as cranial nerve palsies: MR findings

SUMMARY: We report the MR findings of parapharyngeal branchial cleft cyst manifesting as multiple, lower cranial nerve palsies in a 35-year-old woman. On MR images, a well-marginated cystic mass was detected in the right parapharyngeal space, with displacement of both the right internal carotid artery and the right internal jugular vein on the posterolateral side. The cyst contained a whitish fluid that was slightly hyperintense on T1-weighted images and slightly hypointense to CSF on T2-weighted images. No enhancement on contrast-enhanced T1-weighted images was present. The right side of the tongue showed high signal intensity on T2-weighted images, suggesting denervation.     

Neurenteric cyst with alteration of signal intensity on follow-up MR images

SUMMARY: Intracranial neurenteric cysts are uncommon and usually have low intensity on T1-weighted MR images and high intensity on T2-weighted MR images. We report a case of a neurenteric cyst that was situated in front of the medulla oblongata and the size of which increased with alteration of MR signal from high to isointense compared with that of brain on T1-weighted images obtained 33 months after the initial MR images. We think that the signal change of the cyst was probably caused by a change of protein concentration.     

Rathke cleft cysts: CT, MR imaging, and pathologic features

The authors retrospectively reviewed the clinical, computed tomography (CT), and magnetic resonance (MR) imaging findings in seven patients with pathologically proved Rathke cleft cysts. All the cysts were located in the anterior sella turcica or the anterior suprasellar cistern. Five cysts had both intra- and suprasellar components, one was entirely intrasellar, and the other was predominantly suprasellar in location. The size of the cysts ranged from 8 to 20 mm. CT scans demonstrated low-density homogeneous lesions in four cases. On MR images of three of these four cases, the cysts had the same intensity as cerebrospinal fluid on T1- and T2-weighted images, while in the fourth case, the cyst was hyperintense on the T1-weighted images. In the remaining three cases, CT showed slight hyperdensity relative to brain parenchyma, suggestive of contrast enhancement. MR showed signal heterogeneity of these lesions with focal components of diminished signal intensity of T2-weighted images. These same foci appeared iso- to slightly hyperintense on T1-weighted images.     

Pituitary adenoma, craniopharyngioma, and Rathke cleft cyst involving both intrasellar and suprasellar regions: differentiation using MRI

AIMS: To determine the differential magnetic resonance imaging (MRI) features of pituitary adenoma, craniopharyngioma, and Rathke cleft cyst involving both intrasellar and suprasellar regions. MATERIALS AND METHODS: The MRI images of 64 patients with pituitary adenoma (n=38), craniopharyngioma (n=13), or Rathke cleft cyst (n=13) were retrospectively reviewed by three neuroradiologists. The following characteristics were evaluated: shape, volume, extent, component characteristics, signal intensities of solid portions on T2-weighted images, signal intensities of cystic portions on T1-weighted images, and enhancement patterns of solid portions and cyst walls of tumours. Fisher's exact test applied with Bonferroni correction was used for multiple comparison. A flowchart for differential diagnosis was constructed based on statistical analysis of the results. RESULTS: A snowman shape, solid characteristics, and homogeneous enhancement of the solid portion were more common in pituitary adenomas (p<0.017). A superiorly lobulated shape, third ventricle compression by superior tumour extension, mixed solid and cystic characteristics, and reticular enhancement of the solid portion were more common in craniopharyngiomas (p<0.017). Finally, an ovoid shape, a small tumour volume, cystic characteristics, and no or thin cyst wall enhancement were more common in Rathke cleft cysts (p<0.017). The flowchart yielded diagnostic accuracies as follows: 92.1% in pituitary adenoma; 92.3% in craniopharyngioma; 92.3% in Rathke cleft cyst; and 92.2% overall. CONCLUSION: A combination of MRI findings is helpful in the differential diagnosis of the three tumours involving both intrasellar and suprasellar regions.     

Pituitary cysts in childhood evaluated by MR imaging

BACKGROUND AND PURPOSE: Pituitary cysts are common findings on pathologic examination and imaging studies. They are generally considered to be rarer in children than in adults; however, no good data exist to substantiate this opinion. We reviewed MR imaging studies to evaluate the frequency and imaging features of pituitary cysts in children. METHODS: We retrospectively reviewed T1-weighted sagittal images in 341 patients <15 years of age to evaluate for pituitary cysts. Paramagnetic contrast was administered in 86 of the 341 patients. Sagittal or coronal fast spin-echo T2-weighted images were performed in 166 patients. For patients having pituitary cysts, pituitary function was examined by assessing blood levels of pituitary hormones. RESULTS: A cystic pituitary lesion was recognized in 4 patients (1.2%) aged 1-4 years. None of the 4 manifested endocrinologic signs or symptoms or were the results of their laboratory studies abnormal. All the lesions were sharply demarcated and situated just posterior to the anterior pituitary lobe. All were iso- or hypointense compared with the pons on T1-weighted images without contrast enhancement, suggesting a Rathke cleft cyst. MR imaging of a patient with probable low-grade gliomas in the left hypothalamic region and optic chiasma showed complete resolution of a pituitary cyst at a 1-year follow-up study. CONCLUSION: The frequency of pituitary cysts on MR imaging in childhood is almost equal to that of Rathke cleft cysts, as assessed in autopsy studies of subjects aged 10 to 29 years. These cysts are common in children and should be considered, in the absence of signs or symptoms of pituitary dysfunction, as incidental findings.     

Seminal vesicle cyst associated with ipsilateral renal agenesis and papillary carcinoma of the bladder

We report a case of seminal vesicle cyst associated with ipsilateral renal agenesis in a 37-year-old patient with papillary carcinoma of the bladder. Ultrasonography showed absence of the right kidney, a bladder tumour and a round retrovesical hypoechogenic mass with posterior acoustic enhancement. It showed low attenuation on CT, low signal intensity on T1-weighted MR images and high signal intensity on T2-weighted MR images. Intravenous urography (IVU) and cystoscopy were also performed. After surgery, it proved to be a seminal vesicle cyst. The embryology, imaging characteristics and differential diagnosis of seminal vesicle cysts are discussed. Associated findings are also described.     

Unusual appearance of a cisternal hydatid cyst

We herein describe a case of an isolated multilocular hydatid cyst occurring in the basilar cisterns, with nondependent levels of different signal intensities shown on MR images. Three portions were visualized on T1-weighted images: the hyperintense inferior aspect, the isointense central part, and the superior aspect of lower signal intensity. The inferior portion was hypointense on T2-weighted images. This unusual appearance was caused by layering of hydatid sand and may represent a characteristic feature of hydatid disease.     

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM: The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features. MATERIALS AND METHODS: Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features. RESULTS: On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable. CONCLUSION: Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.     

Characteristics of Rathke's cleft cyst in MR imaging.

PURPOSE: Symptoms, macroscopic appearances and microscopic findings of Rathke's cleft cysts with magnetic resonance (MR) imaging. Patients and METHODS: We analyzed the data from 31 patients with pathologically confirmed Rathke's cleft cysts. MR appearances were evaluated on T1WI, T2WI and contrast T1WI. Symptoms, macroscopic appearances and pathological findings were obtained from available medical records. We analyzed the images according to the following criteria: 1. findings on the location and shape of the lesions and form of the lesional wall; 2. the relationship between the maximum diameter of the lesions and symptoms; 3. the relationship between MR and macroscopic appearance; 4. the sites of adjacent contrast enhancement. RESULTS: The lesions were located mostly in both the intrasellar and suprasellar regions for a total of 87%. All lesions revealed either an oval or dumbbell shape with a smooth lesional wall. When correlated with physical symptoms, asymptomatic cases were associated with smaller lesions, while visual disturbances and dizziness were associated with relatively larger lesions. MR lesion signal intensity was related to the content of macroscopic appearance to some degree: the selected lesions showed shortening of T1 and T2 relaxation times in relation to the increase in protein concentration. This should have been macroscopically reflected in the color and turbidity of the liquid within the cyst. Adjacent contrast enhancement around the lesion was found at various sites, but anterior enhancement was most frequent. Circumferential enhancement was revealed to be derived from inflammatory changes. CONCLUSION: Rathke's cleft cyst exhibits a varied MR signal. It may be difficult to differentiate from craniopharyngioma from the intensity alone.     

Neuroradiologic-pathologic correlation in a neurenteric cyst of the clivus

A 28-year-old woman presented with left-sided frontotemporal headache lasting 6 wk. Head CT and MR imaging revealed a clival mass, which was interpreted as a chondrosarcoma. The lesion was removed at endoscopic endonasal surgery; histologic and immunohistochemical findings proved it to be neurenteric cyst. On CT scans, the lesion was lytic, with an intact cortex; it was uniformly hyperintense relative to gray matter on T1-weighted MR images and iso- to hypointense relative to CSF on T2-weighted MR images.     

Glioependymal cysts: CT and MR findings.

Four patients with intracranial glioependymal cysts were evaluated in our institution in the last 7 years. All underwent surgical drainage and biopsy of the cyst wall. Cranial CT revealed a uniformly hypodense lesion with no contrast enhancement in all cases. Magnetic resonance imaging studies revealed a well defined cyst that was isointense to CSF on T1-weighted images and iso- or mildly hyperintense to CSF on proton density and T2-weighted images. In one case, a fluid-fluid level was demonstrated within the cavity, indicating the presence of fluid with a high protein content. A diagnosis of glioependymal cysts can be suggested based on CSF-like intensity patterns on T1-weighted images and iso- or mild hyperintensity on T2-weighted images.     

Intrasphenoidal rathke cleft cyst

Symptomatic Rathke cleft cysts (RCC) are reported in the sellar and suprasellar regions, but no case of sphenoidal RCC has been reported. We report a case of sphenoidal RCC in a 41-year-old man. The lesion was revealed by headaches and diplopia. Symptoms disappeared transiently after a spontaneous rhinorrhea but relapsed 4 months later. MR imaging showed a cystic sphenoidal lesion, isointense on T1-weighted images (WI) with peripheral gadolinium enhancement and hyperintense on T2 WI. The patient underwent surgery through a transrhinoseptal approach. The wall of the sphenoid sinus was paper-thin. The cyst contained a motor-oil-like fluid and communicated widely with the nasal fossa. Its wall was partially extracted. Symptoms and signs ceased after surgery. MR imaging performed 1 year later showed the disappearance of the sphenoidal cyst. Embryological origin of RCCs is discussed. The hypothesis of a continuum between the different epithelial cystic lesions of the sellar and parasellar region is discussed. Imaging has an important impact on the diagnosis; nevertheless, the specific characterization remains difficult.     

MR imaging of thyroglossal duct cysts in adults.

AIM: To describe the magnetic resonance (MR) features of thyroglossal duct cysts (TDC) in adults. PATIENTS AND METHODS: Sixteen patients with TDC underwent MR imaging to obtain T1- and T2-weighted images and T2-weighted fat saturation images. In addition, contrast enhanced images were obtained in five patients. RESULTS: The signal intensity of TDC was of that of a simple cyst in seven (44%) patients, yielding high signal intensity on T2- and low signal intensity on T1-weighted images. In nine (56%), the signal intensity was either intermediate or high on T1-weighted images, the T2 signal intensity in these cases being high (7), intermediate (1) or low (1). Enhancement of the wall of the cyst was present in three of five (60%) patients. All 16 TDC were located at or just to one side of the midline and 12 were embedded in the strap muscles. All TDC were infrahyoid in location but 11 also extended superiorly to be directly related to the hyoid. At the hyoid the cystic component was immediately posterior (6) anterior (3) or anterior and posterior (2) to the bone. Intralaryngeal extension was present in eight (50%) patients. A suprahyoid tract was identified in three patients. The thyroid gland was in a normal location in all patients. CONCLUSION: Thyroglossal duct cysts are most commonly of high T1 signal intensity consistent with high protein content. The tract leading to the base of the tongue is infrequently seen, the diagnosis being determined by the intimate relationship to the hyoid and strap muscles. Intralaryngeal extension in adult patients with TDC is more frequent than reported previously.     

Variable MR findings in ovarian functional hemorrhagic cysts

PURPOSE: To describe the magnetic resonance (MR) findings in ovarian functional hemorrhagic cysts (FHC). MATERIALS AND METHODS: A total of 21 patients with 22 FHC, proven by follow-up ultrasound (US) in 11 women and surgery in 10 women, had US and MR examinations within 24 hours. The study was limited to cysts with obvious an echogenic pattern. All patients had T2-weighted fast spin echo (FSE), T1-weighted spin echo (SE), and T1-weighted SE fat-suppressed sequences. RESULTS: Four cysts (18%) were hypointense on T1-weighted-images without and with fat suppression, and hyperintense on T2-weighted-images. Five cysts (23%) were hypointense on T1-weighted images without and with fat suppression but heterogenous on T2-weighted images. Five cysts (23%) were hypointense on T1-weighted images but showed intermediate signal intensity on T1-weighted fat suppression images and heterogenous signal intensity on T2-weighted images. Two cysts (9%) were entirely intermediate on T1-weighted images. Five cysts (23%) displayed high signal intensity occupying less than 30% of the cystic content on T1-weighted images and one cyst (5%) displayed high signal intensity occupying more than 30% of the cystic content. CONCLUSION: Despite an obvious echogenic pattern on US, 64% of FHC were hypointense on T1-weighted images and 18% were also hyperintense on T2-weighted images. Only 36% demonstrated intermediate or high signal intensity on T1-weighted images.     

MR findings of a giant Bartholin's duct cyst

We describe the case of a 63-year-old woman with a large Bartholin's duct cyst that showed high signal intensity on T1- and T2-weighted magnetic resonance (MR) images. Although Bartholin's duct cyst is the most frequent cystic lesion of the vulva, such a giant cyst is rare.     

Solid aneurysmal bone cyst in the humerus

We report on a 69-year-old woman with a solid variant of aneurysmal bone cyst (solid ABC) in the left humerus with a pathological fracture. Radiographically, the lesion exhibited a relatively well-defined osteolytic lesion in the diaphysis of the left humerus. On magnetic resonance (MR) imaging, the medullary lesion exhibited a homogeneous signal intensity isointense with surrounding normal muscles on the T1-weighted images and a mixture of low and high signal intensity on the T2-weighted images. Contrast-enhanced T1-weighted images revealed diffuse enhancement of the entire lesion. The pathological study showed a proliferation of fibroblasts, histiocytes, chronic inflammatory cells and numerous multinucleated giant cells in a collagenous matrix. Abundant osteoid formation in the matrix was observed, but the cells were devoid of nuclear atypia. Aneurysmal cystic cavities were absent. A review of the English literature found 22 cases of solid ABC of the long bones. Received: 15 February 2000 Revision requested: 18 March 2000 Revision received: 17 April 2000 Accepted: 19 April 2000