Rathke cleft cyst: MR and biomedical analysis of cyst content

Endometriosis MR mimickers: T1-hyperintense lesions

Endometriosis is a chronic and disabling gynecological disease that affects women of reproductive age. Magnetic resonance imaging (MRI) is considered the cornerstone radiological technique for both the diagnosis and management of endometriosis. While MRI offers higher sensitivity compared to ultrasonography, it is prone to false-positive results, leading to decreased specificity. False-positive findings can arise from various T1-hyperintense conditions on fat-suppressed T1-weighted images, resembling endometriotic cystic lesions in different anatomical compartments. These conditions include hemorrhage, hyperproteic content, MRI artifacts, feces, or melanin. Such false positives can have significant implications for patient care, ranging from incorrect diagnoses to unnecessary medical or surgical interventions and subsequent follow-up. To address these challenges, this educational review aims to provide radiologists with comprehensive knowledge about MRI criteria, potential pitfalls, and differential diagnoses, ultimately reducing false-positive results related to T1-hyperintense abnormalities.Critical relevance statementMRI has a 10% false-positive rate, leading to misdiagnosis. T1-hyperintense lesions, observed in the three phenotypes of pelvic endometriosis, can also be seen in various other causes, mainly caused by hemorrhages, high protein concentrations, and artifacts.Key points• MRI in endometriosis has a 10% false-positive rate, leading to potential misdiagnosis.• Pelvic endometriosis lesions can exhibit T1-hyperintensity across their three phenotypes.• A definitive diagnosis of a T1-hyperintense endometriotic lesion is crucial for patient management.• Hemorrhages, high protein concentrations, lipids, and artifacts are the main sources of T1-hyperintense mimickers.

Association Between Pseudoprogression of Vestibular Schwannoma After Radiosurgery and Radiological Features of Solid and Cystic Components

BACKGROUND AND OBJECTIVES

The pathophysiology of vestibular schwannoma (VS) pseudoprogression after Gamma Knife radiosurgery (GKRS) remains unclear. Radiological features in pretreatment magnetic resonance images may help predict VS pseudoprogression. This study used VS radiological features quantified using an automated segmentation algorithm to predict pseudoprogression after GKRS treatment.

METHODS

This is a retrospective study comprising 330 patients with VS who received GKRS. After image preprocessing and T2W/contrast-enhanced T1-weighted image (CET1W) image generation, with fuzzy C-means clustering, VSs were segmented into solid and cystic components and classified as solid and cystic. Relevant radiological features were then extracted. The response to GKRS was classified into "nonpseudoprogression" and "pseudoprogression/fluctuation". The Z test for two proportions was used to compare solid and cystic VS for the likelihood of pseudoprogression/fluctuation. Logistic regression was used to assess the correlation between clinical variables and radiological features and response to GKRS.

RESULTS

The likelihood of pseudoprogression/fluctuation after GKRS was significantly higher for solid VS compared with cystic VS (55% vs 31%, P < .001). For the entire VS cohort, multivariable logistic regression revealed that a lower mean tumor signal intensity (SI) in T2W/CET1W images was associated with pseudoprogression/fluctuation after GKRS ( P = .001). For the solid VS subgroup, a lower mean tumor SI in T2W/CET1W images ( P = .035) was associated with pseudoprogression/fluctuation after GKRS. For the cystic VS subgroup, a lower mean SI of the cystic component in T2W/CET1W images ( P = .040) was associated with pseudoprogression/fluctuation after GKRS.

CONCLUSION

Pseudoprogression is more likely to occur in solid VS compared with cystic VS. Quantitative radiological features in pretreatment magnetic resonance images were associated with pseudoprogression after GKRS. In T2W/CET1W images, solid VS with a lower mean tumor SI and cystic VS with a lower mean SI of cystic component were more likely to have pseudoprogression after GKRS. These radiological features can help predict the likelihood of pseudoprogression after GKRS.

Imaging of pituitary tumors: an update with the 5th WHO Classifications-part 2. Neoplasms other than PitNET and tumor-mimicking lesions

Many types of tumors can develop in the pituitary gland. In the recently revised 5th editions of the World Health Organization (WHO) classifications (2021 WHO Classification of Central Nervous System Tumors and the 2022 WHO Classification of Endocrine and Neuroendocrine Tumors), various changes have been made to the tumors other than pituitary neuroendocrine tumor (PitNET)/pituitary adenoma, as well as PitNET. Adamantinomatous craniopharyngioma and papillary craniopharyngioma are now considered separate tumors in the 5th edition of the WHO classification. Tumors positive for thyroid transcription factor 1, a marker of posterior pituitary cells, are now grouped together in the pituicyte tumor family in the 5th edition of the WHO classification of Endocrine and Neuroendocrine Tumors. Poorly differentiated chordoma is newly listed in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors. In this paper, we present the latest WHO classification of pituitary tumors (adamantinomatous craniopharyngioma, papillary craniopharyngioma, pituitary blastoma, pituicyte tumor family, tumors of pituitary origin other than those of the pituicyte tumor family, germinoma, meningioma, chordoma, metastatic tumors, lymphoma, and pituitary incidentaloma), review diseases requiring differentiation from tumors (pituitary abscess, hypophysitis, pituitary hyperplasia, Rathke's cleft cyst, arachnoid cyst, and aneurysm), and discuss diagnoses based on imaging findings.

MRI-Based Classification of Rathke's Cleft Cyst and Its Clinical Implication

BACKGROUND

Rathke's cleft cysts (RCCs) are benign tumors of the pituitary gland. Small, asymptomatic RCCs do not require surgical treatment, whereas surgical treatment is required for symptomatic RCCs.

METHODS

We retrospectively reviewed medical records of patients with an RCC who were diagnosed and managed in our institution between April 2004 and April 2020 and generated two different cohorts: the observation (n=114) and the surgical group (n=99). Their initial MRI signal characteristics were analyzed. The natural course focusing on cyst size was observed in the observation group and postoperative visual and endocrine outcomes were evaluated in the surgical group.

RESULTS

The characterization of MRI signals of cyst contents in both T1-weighted (T1W) and T2-weighted (T2W) images revealed nine combinations for our 213 patients. Among 115 patients with a high T2W signal, the cysts showed hypo-, iso-, and hyper-intensity on T1W images in 72, 39, and 44 patients, respectively; Type S-low, Type S-iso, and Type S-high. One more major group of 35 patients showed RCCs with hyperintensity on the T1W images and hypointensity on the T2W images named as Type M. In the comparison between observation and surgical groups, we identified only two major groups in which the number of patients in the surgical and observation groups was statistically different: more Type S-low in a surgical group (p<0.001) and more Type M in an observation group (p=0.007). In subgroup analysis, the range of change in the cyst size was the highest in Type S-high in the observation group (p=0.028), and intergroup differences in visual and endocrine outcomes were not evident in the surgical group.

CONCLUSION

MRI characteristics help to predict the natural course of RCCs. We identified subgroups of RCCs which are more or less likely to require surgical intervention.

Pineal cyst: results of long-term MRI surveillance and analysis of growth and shrinkage rates

OBJECTIVE

Pineal cyst (PC) is a relatively common true cyst in the pineal gland. Its long-term natural course remains ill defined. This study aims to evaluate the long-term natural history of PC and examine MRI risk factors for cyst growth and shrinkage to help better define which patients might benefit from surgical intervention.

METHODS

The records and MRI of 409 consecutive patients with PC were retrospectively examined (nonsurgical cohort). Cyst growth and shrinkage were defined as a ≥ 2-mm increase and decrease in cyst diameter in any direction, respectively. In addition to size, MRI signal intensity ratios were analyzed.

RESULTS

The median radiological follow-up period was 10.7 years (interquartile range [IQR] 6.4-14.3 years). The median change in maximal diameter was -0.6 mm (IQR -1.5 to 1.3 mm). During the observation period, cyst growth was confirmed in 21 patients (5.1%). Multivariate logistic regression analysis revealed that only age (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.93-0.99, p < 0.01) was significantly associated with cyst growth. No patient required resection during the observation period. Cyst shrinkage was confirmed in 57 patients (13.9%). Multivariate analysis revealed that maximal diameter (OR 1.22, 95% CI 1.12-1.35, p < 0.01) and cyst CSF T2 signal intensity ratio (OR 9.06, 95% CI 1.38-6.62 × 101, p = 0.02) were significantly associated with cyst shrinkage.

CONCLUSIONS

Only 5% of PCs, mainly in patients younger than 50 years of age, have the potential to grow, while cyst shrinkage is more likely to occur across all age groups. Younger age is associated with cyst growth, while larger diameter and higher signal intensity on T2-weighted imaging are associated with shrinkage. Surgery is rarely needed for PCs, despite the possibility of a certain degree of growth.

A study on clinical outcomes of Rathke's cleft cyst in patients managed conservatively

OBJECTIVES

The primary objective was to investigate the clinical presentation, hormonal dysfunction, imaging characteristics and natural history of RCCs that were managed conservatively. Secondary objective was to identify factors associated with cyst progression.

METHODS

A retrospective review of patients with the clinical diagnosis of RCC-identified from word search from radiology reports that were followed up from January 1999 to March 2019 was performed. The demographics, clinical data, radiological features and outcomes were reviewed and analyzed.

RESULTS

105 patients were identified with a median follow up of 6 years. 68 patients (64.8%) were managed conservatively from diagnosis till last follow up while 37 patients (35.2%) underwent surgery, with 26 operated at time of diagnosis and 11 operated upon monitoring. For patients managed conservatively from diagnosis till last follow up, incidental finding was the most common presentation. 19.1% had either one or more axes of hormonal dysfunction, with hypogonadism and hypocortisolemia being the commonest ones. Imaging features were variable. 66.2% of patients had T2W hyperintensity on MRI. Pathognomonic feature of intracystic nodule was present in only 14.7% of patients. Among the 79 patients with repeated MRI imaging (68 from conservative group and 11 from surgical group), 32.9% of patients developed cyst progression while 67.1% had either static disease or regression in size of RCC. Median time to progression of cyst was 14 months. Longer median follow up duration and presence of pituitary stalk displacement at presentation were associated with cyst progression. Only one patient developed new endocrine dysfunction.

CONCLUSION

2/3 of the RCCs had static disease or even regression in the size of the cyst. They rarely gave rise to additional endocrine dysfunction by adopting observant approach. Cyst progression was demonstrated in 1/3 of patients. Conservative treatment remained a reasonable treatment for patients without significant symptoms.

T2 hypointense signal discovered incidentally at the posterior edge of the adenohypophysis on MRI: its prevalence and morphology and their relationship to age

PURPOSE

T2 hypointense signal at the posterior edge of the adenohypophysis (T2HSPA) on magnetic resonance imaging (MRI) is incidentally encountered. We aimed to investigate the prevalence and morphology of T2HSPA and their relationship to age.

METHODS

A total of 212 cases between 3 and 88 years old were examined. Sagittal T2-weighted image (T2WI) was evaluated for the presence of T2HSPA, which classified by its morphology into two types (belt-like or nodal). The Wilcoxon rank sum test and chi-square test were used to evaluate the differences between the groups. The T2HSPA was extracted by ImageJ software and measured as a cross-sectional area (CSA) quantitatively by threshold setting. We examined the relationship between CSA of T2HSPA and age, and Spearman's correlation coefficients were used for statistical analysis.

RESULTS

Of the 212 cases, 80 (37.7%) were identified with T2HSPA. The groups with T2HSPA were significantly younger than the groups without it (p = .01). Groups with belt-like T2HSPA were significantly younger than the groups with nodal T2HSPA (p = .01). There was a weak negative correlation between CSA of T2HSPA and age (p = .02).

CONCLUSION

T2HSPAs were incidentally detected in 37.7% of all cases, tended to be more common in younger cases, and their morphology was related to age. They seem to have little clinical significance as they tend to decrease in size with age.

Neurenteric Cyst of the Posterior Cranial Fossa: A Case Report and Literature Review

Neurenteric cysts (NCs) are rare benign endodermal lesions of the central nervous system (CNS), most commonly found in the spinal cord. Intracranial lesions are rare, among which the posterior fossa appears to be the predominant location.

We present a case of a 60-year-old man who presented with a suddenly decreased level of consciousness. After a series of radiological studies were done, a multilobulated cystic lesion in the right posterior fossa was observed. Surgical resection was performed and based on its histopathological characteristics, NC diagnosis was confirmed.

Because of the wide list of differential diagnoses and low specificity of radiological features, surgical gross total resection remains the most effective treatment, followed by diagnosis confirmation through histopathological techniques.

Cyst Type Differentiates Rathke Cleft Cysts From Cystic Pituitary Adenomas

Purpose

A classification system for cystic sellar lesions does not exist. We propose a novel classification scheme for these lesions based on the heterogeneity of the cyst wall/contents and the presence of a solid component on imaging.

Methods

We retrospectively reviewed 205 patients’ medical records (2008–2020) who underwent primary surgery for a cystic sellar lesion. Cysts were classified a priori into 1 of 4 cyst types based on the heterogeneity of the cyst wall/contents and the presence of a solid component imaging. There was high interrater reliability. Univariable and multivariable models were used to estimate the ability of cyst type to predict the two most common diagnoses: Rathke cleft cyst (RCC) and cystic pituitary adenoma.

Results

The frequencies of RCC and cystic pituitary adenoma in our cohort were 45.4% and 36.4%, respectively. Non-neoplastic lesions (e.g., arachnoid cysts and RCC) were more likely to be Type 1 or 2, whereas cystic neoplasms (e.g., pituitary adenomas and craniopharyngiomas) were more likely to be Type 3 or 4 (p<0.0001). Higher cyst types, compared to Type 1, had higher odds of being cystic pituitary adenomas compared to RCCs (OR: 23.7, p=0.033, and 342.6, p <0.0001, for Types 2 and 4, respectively). Lesions with a fluid-fluid level on preoperative MRI also had higher odds of being pituitary adenomas (OR: 12.7; p=0.023). Cystic pituitary adenomas were more common in patients with obesity (OR: 5.0, p=0.003) or symptomatic hyperprolactinemia (OR: 11.5; p<0.001, respectively). The multivariable model had a positive predictive value of 82.2% and negative predictive value of 86.4%.

Conclusion

When applied to the diagnosis of RCC versus cystic pituitary adenoma, higher cystic lesion types (Type 2 & 4), presence of fluid-fluid level, symptomatic hyperprolactinemia, and obesity were predictors of cystic pituitary adenoma. Further validation is needed, but this classification scheme may prove to be a useful tool for the management of patients with common sellar pathology.

Anterior pituitary function in Rathke's cleft cysts versus nonfunctioning pituitary adenomas

Although Rathke's cleft cysts (RCCs) are common sellar/parasellar lesions, studies examining pituitary function in patients with nonsurgical RCC are limited. This study aimed to clarify the importance of RCCs, including small nonsurgical ones, as a cause of hypopituitarism by determining the prevalence of pituitary hormone secretion impairment and its relationship to cyst/tumor size in patients with RCC and in those with nonfunctioning pituitary adenoma (NFA). We retrospectively investigated the basal levels of each anterior pituitary hormone, its responses in the stimulation test(s), and cyst/tumor size in patients with RCC (n = 67) and NFA (n = 111) who were consecutively admitted to our hospital for endocrinological evaluation. RCCs were much smaller than NFAs (median height, 12 vs. 26 mm). The prevalence of gonadotropin, PRL, and GH secretion impairment in RCC was lower in comparison to NFA (19% vs. 44%, 34% vs. 61%, and 24% vs. 46%, respectively), whereas the prevalence of TSH and ACTH secretion impairment was comparable (21-27% and 17-24%, respectively). A significant positive relationship between cyst/tumor size and number of impaired hormones was observed in both groups, but smaller cysts could cause hormone secretion impairment in RCC. Stimulation tests suggested that most hormone secretion impairment was attributable to the interrupted hypothalamic-pituitary axis in both groups. Therefore, RCC, even small ones, can cause pituitary dysfunction. Different mechanisms may underlie hypothalamic-pituitary interruption in RCC and NFA.

Useful preoperative examination findings to classify the grade of ovarian primary mucinous tumor

PURPOSE

To evaluate various imaging features on magnetic resonance imaging (MRI) and tumor markers and their utility to assess various grades of ovarian primary mucinous tumors (OPMTs): benign, borderline, or malignant.

METHODS

Ninety-five pathologically diagnosed OPMTs [53 benign, 24 borderline malignant (BM), and 18 malignant] were selected in this retrospective study. MRI features of the ovarian mass, namely the maximum diameter, honeycomb loculi, solid components (SC), stained-glass pattern, and signal intensity of the cyst on T1- (T1WI) and T2-weighted imaging (T2WI) with/without fat suppression, and preoperative STMs, namely carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, and CA125, were compared between the three tumor grades using univariate analysis. We also analyzed the findings to estimate the pathological diagnosis using classification tree (CT) analysis.

RESULTS

Maximum diameter, honeycomb loculi, SC, stained-glass pattern, signal intensity of the cyst [hyperintensity on both T1WI and T2WI (T1-hyper/T2-hyper), and hyperintense on T1WI and hypointense on T2WI (T1-hyper/T2-hypo)], and CEA and CA 19-9 concentrations were significantly different between the three tumor grades (p < 0.05). The concordance rate with the pathological diagnosis was the highest with diagnosis by the CT comprising T1-hyper/T2-hypo, CEA, and CA 19-9 and by the CT comprising T1-hyper/T2-hypo, CEA, and SC.

CONCLUSION

Four types of findings were important for OPMT grading. Lesions negative for both T1-hyper/T2-hypo and CEA suggest benign; lesions positive for T1-hyper/T2-hypo and negative for CA 19-9 or SC suggest BM; and lesions negative for T1-hyper/T2-hypo and positive for CEA, or positive for both T1-hyper/T2-hypo and CA 19-9 or SC suggest malignancy.

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Magnetic resonance imaging of the hypothalamo-pituitary region

The diagnosis and management of mass lesions in the sellar and parasellar areas remain challenging. When approaching patients with possible sellar or hypothalamic masses, it is important not only to focus on imaging but also detect possible pituitary hormone deficits or excess, in order to establish an appropriate diagnosis and initiate treatment. The imaging modalities used to characterize hypothalamic and pituitary lesions have significantly evolved over the course of the past several years. Computed tomography (CT) and CT angiography play a major role in detecting various sellar lesions, especially in patients who have contraindications to magnetic resonance imaging (MRI) and can also yield important information for surgical planning. However, MRI has become the gold standard for the detection and characterization of hypothalamic and pituitary tumors, infections, cystic, or vascular lesions. Indeed, the imaging characteristics of hypothalamic and sellar lesions can help narrow down the differential diagnosis preoperatively. In addition, MRI can help establish the relationship of mass lesions to surrounding structures. A pituitary MRI examination should be obtained if there is concern for mass effect (including visual loss, ophthalmoplegia, headache) or if there is clinical suspicion and laboratory evidence of either hypopituitarism or pituitary hormone excess. The information obtained from MRI images also provides us with assistance in planning surgery. Using intraoperative MRI can be very helpful in assessing the adequacy of tumor resection. In addition, MRI images yield reliable data that allow for noninvasive monitoring of patients postoperatively.

The neuroimaging features of Rathke's cleft cysts in children with endocrine-related diseases

PURPOSE We aimed to evaluate the frequency and neuroimaging features of Rathke's cleft cysts (RCCs) in children examined for endocrine-related diseases and to determine changes in the neuroimaging features of RCCs during the follow-up of children. We hypothesize that RCCs are being more commonly diagnosed in children with endocrine-related diseases and most of the RCCs show neither fluid intensity nor intensity due to high protein content on magnetic resonance imaging (MRI). METHODS After approval by the local ethics committee, the medical records and contrast-enhanced pituitary MRI of 833 children (boys/girls, 338/495; mean age±SD, 9.4±3.7 years) were retrospectively reviewed between January 2016 and January 2019. The size, location, signal intensities, and postcontrast enhancement pattern of RCCs were assessed by a pediatric radiologist. Same imaging features were also independently reviewed by another radiologist to determine the interobserver agreement by using the kappa statistics (κ) and intraclass correlation coefficient (ICC). RESULTS RCC was evident on MRI in 13.5% of the patients (boys/girls, 39/74; mean age±SD, 9.8±3.9 years). The mean size of RCCs was 5.5 mm (range, 3.1-8.5 mm). An RCC frequency higher than expected was found in patients with central precocious puberty, diabetes insipidus, and hypersecretion of prolactin (P = 0.007). The mean size of RCCs did not show significant differences among the clinical indications for MRI (P ≥ 0.461). All RCCs showed abnormal signal on T2-weighted image and most (89%) showed neither fluid intensity nor intensity due to high protein content (i.e., isointense on T1-weighted imaging and hypointense on T2-weighted imaging compared with the normal anterior pituitary gland). Eighty-four patients with RCCs (74%) had follow-up MRI and the mean follow-up was 1.5 years. In follow-ups, five RCCs disappeared; the mean size of 10 RCCs increased and that of 6 RCCs decreased. These size changes were not statistically significant (P = 0.376). No signal intensity changes of RCCs were seen during the follow-up, except for 4 RCCs, whose protein content increased over time and T1 signals increased on imaging. Interobserver agreements were almost perfect for the MRI findings of RCCs (κ and ICC range, 0.81-1, P < 0.001). CONCLUSION RCCs were not uncommon in patients examined for endocrine-related diseases, and nearly 1 in 10 patients had an RCC. The size and signal intensities of RCCs may change over time and the evolution of RCCs is unpredictable. Most RCCs showed neither fluid intensity nor intensity due to high protein content on MRI, and all RCCs had an abnormal signal on T2-weighted imaging, thus eliminating the need to administer a contrast agent at follow-up imaging of the patients.

Therapeutic Strategies and Prognostic Factors Based on 121 Spinal Neurenteric Cysts

BACKGROUND

Limited data existed to guide the management of intraspinal neurenteric cysts (ISNECs).

OBJECTIVE

To evaluate the risk factors for progression-free survival (PFS), elucidate the radiological features of ISNECs, and propose a treatment protocol.

METHODS

From 2003 to 2015, 121 patients with pathologically confirmed ISNECs treated at our institute were included in this study. Pertinent risk factors were evaluated.

RESULTS

Gross total resection (GTR) was achieved in 55 (44.6%) patients; 106 (87.6%), 12 (9.9%), and 3 (2.5%) ISNECs were classified as Wilkins A, B, and C, respectively. After a median follow-up duration of 64.2 mo, recurrence occurred in 25 (22.7%) patients, with a median PFS time of 43.1 mo. The actuarial PFS rates at 5 and 10 yr were 73.2% and 66.2%, respectively. The actuarial overall survival rates at 5 and 10 yr were 100% and 97.6%, respectively. Non-GTR (hazard ratio [HR], 5.836; 95% confidence interval [CI], 1.698-20.058; P = .005), Wilkins B/C (HR, 3.129; 95% CI, 1.009-9.702; P = .048), and a history of surgical resection (HR, 3.690; 95% CI, 1.536-8.864; P = .004) were adverse factors.

CONCLUSION

GTR and Wilkins A were favorable factors for PFS. If tolerable, GTR alone was advocated as an optimal treatment. Because of the benign nature and favorable prognosis, non-GTR was an alternative if GTR failed. Close follow-up was needed because of the recurrent tendency of ISNEC. Future study with a large cohort is necessary to verify our findings.

Endodermal Cyst with a Non-enhancing Nodule in the Quadrigeminal Cistern Developed in an Octogenarian

BACKGROUND

Intracranial endodermal cysts are congenital lesions that generally develop in the cerebellopontine angle and ventral brainstem of the posterior fossa, whereas endodermal cysts in the quadrigeminal cistern are very rare. We report a rare case of an endodermal cyst in the quadrigeminal cistern with a non-enhancing nodule that developed in patient over 80 years of age.

CASE DESCRIPTION

An 85-year-old man presented to our hospital with progressing gait disturbance and urinary incontinence. Preoperative images showed a cystic mass lesion with a nodule in the quadrigeminal cistern and hydrocephalus. There was no enhanced portion in the lesion, and the intensity of the cyst on magnetic resonance imaging revealed a high protein concentration. Subtotal resection was performed due to the adhesion of the cyst to the brainstem. It was diagnosed as an endodermal cyst. The postoperative course was uneventful, and hydrocephalus improved.

CONCLUSIONS

This is a rare case of an intracranial endodermal cyst in terms of location and age of onset compared with previous reports. This case demonstrates that endodermal cysts should be considered as a differential diagnosis for lesions in the quadrigeminal cistern with high protein concentration in the cyst and nodule representing chronic inflammation, regardless of enhancing effects.

A case of central diabetes insipidus associated with a congenital cyst of the sella turcica in a young cat

Case summary

A 1-year-old neutered male domestic shorthair cat was presented for polyuria and polydipsia which had progressed since adoption, 7 months previously. On admission, clinical examination did not reveal any remarkable features. Urinalysis showed marked hyposthenuria and calculated plasma osmolality was high, suggesting diabetes insipidus. A positive response to desmopressin administration appeared to confirm pituitary dysfunction. Brain MRI revealed a lesion compatible with a cyst or a neoplasm compressing the pituitary gland. A follow-up MRI performed 9 months later showed that the lesion was stable, which at first argued in favour of a congenital pituitary cyst. Intranasal administration of desmopressin was then used to achieve a long-term clinical response.

Relevance and novel information

Central diabetes insipidus (CDI) is a rare cause of polyuria and polydipsia in cats, resulting from inadequate or impaired secretion of antidiuretic hormone from the posterior pituitary gland. Recognised causes include head trauma, central nervous system (CNS) neoplasia, idiopathic CDI and congenital pituitary cysts. Apart from one cat with CNS lymphoma, the few previously reported feline cases have described CDI in young cats with a previous history of trauma, but brain imaging has rarely been performed to look for underlying anatomical abnormalities. This report describes the first case of CDI in a cat with a confirmed congenital pituitary cyst and, as in previous cases, demonstrates successful treatment with desmopressin.

Bronchogenic Cyst: Skull Base Lesions with Extracranial Extension

BACKGROUND

Intracranial bronchogenic cysts (BCs) are extremely rare. To our knowledge, this is the first report of a BC in which lesions involve the middle and posterior cranial fossa, as well as the infratemporal fossa.

CASE DESCRIPTION

We present the case of a 38-year-old woman who suffered from a cranial nerve dysfunction for 2 years. Magnetic resonance imaging showed that there were skull base communication lesions across the middle and posterior fossa. The patient was operated on through an infratemporal fossa approach. The final diagnosis was BC after histopathologic examination and immunohistochemical verification. The patient's neurologic dysfunction was partially ameliorated at the half-year follow-up.

CONCLUSIONS

Intracranial BCs are rare. However, they should be considered in the differential diagnosis for cystic lesions with edge enhancement or extracranial extension.

Proton Magnetic Resonance Spectroscopy Characterization of Rathke's Cleft Cysts (RCCs): Relevance to the Differential Diagnosis of Pituitary Adenomas and RCCs

BACKGROUND

Rathke's Cleft Cysts (RCCs) are rare epithelial cysts arising from remnants of the Rathke pouch in the pituitary gland. A subset of these lesions enlarge and produce a mass effect with consequent hypopituitarism, and may result in visual loss. Moreover, some RCCs with a high intra-cystic protein content may mimic cystic pituitary adenoma, which makes their differential diagnosis ambiguous. Currently, medical professionals have no definitive way to distinguish RCCs from pituitary adenomas. Therefore, preoperative confirmation of RCCs would be of help to medical professionals for the management and proper surgical decision making. The goal of this study is to identify molecular markers in RCCs.

METHODS

We characterized aqueous and chloroform extracts of surgically resected RCCs and pituitary adenomas using ex vivo ¹H NMR spectroscopy.

RESULTS

All RCCs exclusively showed the presence of mucopolysaccharides which are glycosaminoglycans (GAGs) made up of disaccharides of aminosugars and uronic sugars.

CONCLUSION

GAGs can be used as metabolite marker for the detection of RCCs and this knowledge will lay the groundwork for the development of a non-invasive, in vivo magnetic resonance spectroscopy methodology for the differential diagnosis of RCCs and pituitary adenomas using clinical MRI scanners.

Evaluation of image quality of pituitary dynamic contrast-enhanced MRI using time-resolved angiography with interleaved stochastic trajectories (TWIST) and iterative reconstruction TWIST (IT-TWIST)

BACKGROUND

Time-resolved angiography with interleaved stochastic trajectories (TWIST) is a keyhole imaging with frequent sampling of central k-space data and view-sharing for the peripheral k-space of dynamic phases. IT-TWIST is a technique to reconstruct images with a smaller temporal footprint using the same raw data obtained with TWIST by iterative reconstruction.

PURPOSE

To compare image quality between TWIST and IT-TWIST in 3D pituitary DCE-MRI.

STUDY TYPE

Retrospective observation study.

POPULATION

Fifty-one patients (23 men, 28 women) who underwent 3D pituitary DCE-MRI using TWIST between July 2016 and April 2017.

FIELD STRENGTH/SEQUENCE

3T/TWIST and IT-TWIST.

ASSESSMENT

Visual evaluation was conducted for image quality of delineation of the pituitary stalk and posterior lobe during the early arterial phase, cerebral white matter near the sella turcica, and the mass lesion. Bolus sharpness of the pituitary stalk, posterior lobe, and bilateral cavernous sinus was evaluated on the enhancement slope map calculated from TWIST and IT-TWIST. Temporal stability of intensity of the nonenhanced area was evaluated on temporal standard deviation (SD) maps calculated from TWIST and IT-TWIST.

STATISTICAL TESTS

Paired t-test or Wilcoxon rank-sum test was used to test the differences between TWIST and IT-TWIST in both visual evaluation and region of interest evaluation.

RESULTS

Scores of visual evaluations for IT-TWIST were significantly better than those for TWIST (P < 0.001) in all items. Enhancement slope for IT-TWIST was significantly higher than that for TWIST in posterior lobe, and right and left cavernous sinus (P < 0.001). Temporal SD for IT-TWIST was significantly lower than that for TWIST in all items, with statistical significance (P < 0.001).

DATA CONCLUSION

IT-TWIST yielded better visualization, and better enhancement slope, and less temporal SD compared with TWIST in 3D pituitary DCE-MRI. Evidence Level: 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1497-1506.

Predictive Factors for Rathke's Cleft Cyst Consistency

OBJECTIVE

Rathke's cleft cysts (RCCs) may have various anatomic, clinical, and radiologic characteristics, which may be related to their differences in texture or consistency. The purpose of the study was to investigate RCCs based on consistency.

METHODS

We retrospectively reviewed 25 cases of patients with RCCs who underwent endoscopic endonasal transsphenoidal surgery between 2008 and 2018. Cases were divided into 3 types based on cyst consistency: fluid (serous) or type A (n = 4); semi-fluid (mucoid) or type B (n = 17); and non-fluid (caseous) or type C (n = 4). Demographic, clinical, radiologic, and surgical characteristics for each group were analyzed.

RESULTS

All type A RCCs (100%) had visual impairment. The mean age (42.8 ± 13 years) and cyst volume (2442.5 ± 533.6 mm³) were higher in these patients. T1-weighted images were hypointense and T2-weighted images were hyperintense on magnetic resonance imaging. Type B RCCs were more frequently encountered (68%). Although headache was the most common (82.3%) symptom, endocrine disorders were also prevalent (52.9%). T1-weighted images were typically isointense or hyperintense on magnetic resonance imaging. Type C RCCs had the youngest patient population (30.3 ± 10.2 years) and T2-weighted images were predominantly hypointense in this group.

CONCLUSIONS

The proposed novel consistency classification of RCCs will provide a practical tool for more accurately estimating the nature of the pathology, because each type has its own specific characteristics. Furthermore, the new classification of RCCs may aid in planning a consistency-specific surgery.

Entirely Suprasellar Rathke Cleft Cysts: Clinical Features and Surgical Efficacy of Endoscopic Endonasal Transtuberculum Sellae Approach

BACKGROUND

Rathke cleft cysts (RCCs) arise from the remnant of Rathke pouch and are usually found in the intermediate lobe. In most cases, RCCs remain intrasellar and extend into the suprasellar region. Rarely, they emerge entirely into the suprasellar cistern-entirely suprasellar Rathke cleft cyst (ESSRCC).

METHODS

We retrospectively reviewed medical records of 7 patients (5.5%) with ESSRCC among 128 patients with a diagnosis of RCC from January 1994 to September 2018. Of RCC cases, 70 were treated surgically. Patient age and sex, symptoms, magnetic resonance imaging findings, cyst diameter, presence of preoperative or postoperative hypopituitarism, operative procedures and complications, and functional outcomes at the final follow-up were investigated.

RESULTS

All patients with ESSRCC were women with mean age 45.7 years (range, 29-69 years) at diagnosis. All patients experienced headache, mainly in the retro-orbital region. Mean ESSRCC diameter was 9.9 mm (range, 6-14 mm). Most cases exhibited hyperintensity on both T1-weighted and T2-weighted imaging. The endoscopic endonasal transtuberculum sellae approach relieved headache effectively and safely in 5 patients. Postoperative endocrinologic functions were almost entirely preserved. No patient experienced recurrence during the follow-up period.

CONCLUSIONS

RCCs should be considered in the differential diagnosis of suprasellar cysts. The endoscopic endonasal transtuberculum sellae approach has an advantage in visualizing these lesions owing to the direction of light from the endoscope. Headache could be treated effectively with the endoscopic endonasal transtuberculum sellae approach without recurrence of cysts or pituitary dysfunction.

Magnetic resonance characterization of the 'dot sign' in colloid cysts of the third ventricle

PURPOSE

To determine the incidence of the 'dot sign' in patients with colloid cysts of the third ventricle and to characterise its MRI appearances.

MATERIALS AND METHODS

Single institution retrospective analysis between January 2007 and October 2016 of all patients with either an imaging or imaging and histology-confirmed diagnosis of colloid cysts of the 3rd ventricle was undertaken. For all cases, MRI signal intensities of the cyst fluid component were graded by two independent radiologists relative to brain parenchyma. Presence of a dot, and if present, its size and relative position within the cyst were recorded. Signal intensities of the dot were then similarly assessed.

RESULTS

37 cases of colloid cyst were identified. Of these 37.8% (n = 14) demonstrated the dot sign. The majority (11 of 14) were observed inferiorly within the cyst; two cases were anteroinferior, and one other was posterior. All identified intracystic nodules displayed low signal intensity with respect to cyst fluid on T2 weighted sequences, and only two nodules were hypointense to fluid on T1-weighted imaging, with the remainder either iso- or hyperintense.

CONCLUSIONS

An intracystic low T2 'dot' is a common MRI feature of colloid cysts of the third ventricle, and to our knowledge not previously systematically described. Presence of such a dot should not only not dissuade from a diagnosis of colloid cyst being made, but should in fact be used to strengthen the imaging diagnosis.

Rathke Cleft Cyst with Entirely Ossified Cyst Wall and Partially Solid Cyst Content: A Case Report and Literature Review

BACKGROUND

In Rathke cleft cysts (RCCs), inflammation by the cyst contents infrequently spreads to the surrounding structures. Calcification, which is regarded as a result of chronic inflammation of the cyst wall, can rarely be found in RCCs. Moreover, ossification is extremely rare.

CASE DESCRIPTION

A 60-year-old woman experienced headaches, fatigue, and weight loss owing to pan-hypopituitarism. Magnetic resonance imaging revealed a mass lesion in the sellar region, which was composed of two different parts, with hypointensity anteriorly and hyperintensity posteriorly on T1-weighted image, and the rim with significant hypointensity entirely on T2-weighted image. During the transsphenoidal surgery, the cyst wall was so rigid that it was difficult to cut and remove it. The cyst contained mucinous fluid with both old and new hemorrhages, and a yellowish, elastic hard, solid nodule. Postoperative histologic diagnosis was RCC with unusual lymphocyte infiltration, massive granulation, and mature bone formation. Six months later, the fluid in the cyst reaccumulated, and the patient complained of headaches. Removal of the entire cyst wall and the aspiration of the cyst content were performed to collapse the cyst cavity and, consequently, to prevent further recurrence. Postoperatively, panhypopituitarism was unchanged and the symptoms were treated with hormonal replacement. The cyst has not recurred for 2 years after the second surgery.

CONCLUSIONS

Persistent, long-term inflammation induced by the RCC content, mucin-containing fluid, and several phases of hemorrhage presumably promoted the formation of mature bone on the cyst wall and of the elastically solid nodule within the cyst.

Pediatric symptomatic Rathke cleft cyst compared with cystic craniopharyngioma

INTRODUCTION

Symptomatic Rathke cleft cysts (RCCs) are rarely detected in neuroradiological screening and are less commonly found in children than in adults. However, when RCCs are observed in children, it is important to carefully distinguish a RCC from a cystic craniopharyngioma (CP) even if surgically treated or conservatively followed up.

METHODS

We conducted a retrospective review of clinical data from 11 patients with symptomatic RCCs whose ages were under 18 years and compared the data with data from 15 age- and sex-matched patients with cystic CP who were treated at our institute.

RESULTS

The mean age of the patients with RCCs was 12.2 years (range, 6-18). There were six males and five females. As initial symptoms, nine patients presented with headache, while two each had impaired visual function, diabetes insipidus, and activity loss. The 14 patients with CP suffered from impaired visual function. Magnetic resonance imaging (MRI) mainly showed hyperintensity on T1-weighted images (WIs) and hypointensity on T2-WI in patients with RCC. However, patients with CP had characteristic hyperintensity on T2-WI. The average maximum diameter of the RCCs was 19.0 mm on average (range, 8-33 mm). The RCCs were thus significantly smaller than CPs (34.9 mm; range, 21-54 mm). The RCCs were usually oval or dumbbell-shaped and regular in appearance, while the larger CPs were lobular and irregular. A preoperative endocrinological evaluation revealed insufficiencies in four axes in five patients with RCC. Postoperative endocrinological status improved in three patients, remained unchanged in three, and worsened in one. The gonadotropin axis was damaged in a majority (nine) of the patients with CP preoperatively. Postoperative evaluation revealed deficits in five axes in 14 patients with CP, which is a significantly different trend than observed in patients with RCC. Eight patients underwent surgical procedures (transsphenoidal surgery (TSS) in four, craniotomy in four). Two of these patients experienced a recurrence of the cysts. One of these patients subsequently underwent two craniotomies followed by radiation and other underwent TSS. Among the three conservatively treated patients, two experienced a transient worsening of their symptoms along with cyst enlargement. However, none of the three conservatively treated patients required an operation.

CONCLUSIONS

When RCCs become symptomatic in children, the most common symptom they lead to is headache. The cysts are commonly small, regular, and oval in shape. Hypointensity of cyst contents on MRI is a characteristic of RCCs, which distinguishes them from CPs. Surgical intervention can be effective and lead to the relief of symptoms without a high rate of complications. However, there seems to be a relatively high recurrence rate following surgery. Thus, if the patient's symptoms remain minor, the surgical treatment option should be used only when prudent, as the patient's symptoms may improve over time.

T1 Hyperintense Prepontine Mass with Restricted Diffusion--A White Epidermoid or a Neuroenteric Cyst?

Neuroenteric cysts (NC) are benign, congenital malformation which are of endodermal origin commonly located in the central nervous system. We report a case of intracranial NC with squamous metaplasia and xanthogranulomatous response masquerading as a white epidermoid on conventional MRI sequences. Lesion showed two components on T2W-images. We observed differential diffusion characteristics including fractional anisotropy, radial diffusivity and axial diffusivity within the two components of the lesion.

Intraspinal Neurenteric Cysts in Children

Background:

Neurenteric cysts are rare congenital epithelium-lined cysts of the central nervous system. They are found predominantly in the spinal cord, with lower incidence in the intracranial compartment, and may be associated with various other congenital spinal anomalies. Seven patients with symptomatic intraspinal neurenteric cysts are presented.

Materials and Methods:

Seven patients with intraspinal neurenteric cysts aged from nine months to ten years treated at this hospital from May 2000 to July 2006 were reviewed. The clinical manifestations, imaging and surgical findings of patients were analyzed retrospectively. All patients underwent operation. One patient's cervical neurenteric cyst was resected using the lateral cervical approach, and the other six resections were performed with posterior approach.

Results:

All seven patients presented with neurological involvement. One patient had an intramedullary cyst, while the other six cysts were situated ventrally. Three patients' cysts occurred in the cervical region, two in the cervicothoracic region, one in the thoracic region and one in the lumbar region. One patient had bony anomalies, and one had a lumbar posterior occult spinal dysraphism. Five patients' symptoms improved rapidly after surgery.

Conclusions:

Intraspinal neurenteric cysts in children are rare and most occur ventral to the spinal cord. Magnetic resonance imaging (MRI) is the most effective imaging modality. Earlier diagnosis and surgical resection of spinal neurenteric cysts improves prognosis.

Pituitary apoplexy: an update on clinical and imaging features

Pituitary apoplexy (PA) is a rare and potentially fatal clinical condition presenting acute headache, vomiting, visual impairment, ophthalmoplegia, altered mental state and possible panhypopituitarism. It mostly occurs in patients with haemorrhagic infarction of the pituitary gland due to a pre-existing macroadenoma. Although there are pathological and physiological conditions that may share similar imaging characteristics, both clinical and imaging features can guide the radiologist towards the correct diagnosis, especially using magnetic resonance imaging (MRI). In this review, we will describe the main clinical and epidemiological features of PA, illustrating CT and MRI findings and discussing the role of imaging in the differential diagnosis, prognosis and follow-up. Teaching points • Headache, ophtalmoplegia and visual impairment are frequent symptoms of pituitary apoplexy. • CT is often the first imaging tool in PA, showing areas of hyperdensity within the sellar region. • MRI could confirm haemorrhage within the pituitary gland and compression on the optic chiasm. • Frequent simulating conditions are aneurysms, Rathke cleft cysts, craniopharingioma and mucocele. • The role of imaging is still debated and needs more studies.

Clinical and radiological findings of incidental Rathke's cleft cysts in children and adolescents

PURPOSE

In the pediatric population, Rathke's cleft cysts (RCCs) are known to be an infrequent cause of headaches, visual disturbances, and pituitary dysfunction. We investigated the clinical characteristics of children in whom RCCs were incidentally discovered and evaluated whether RCCs influence the treatment response of patients with proven endocrinopathy.

METHODS

A retrospective analysis was conducted in 34 patients with RCCs who were diagnosed between 2006 and 2013 at Hallym University Medical Center. Their clinical, hormonal, and imaging findings were reviewed. We evaluated the clinical outcomes of the patients with concomitant RCCs and endocrinopathy compared to matched controls.

RESULTS

Twenty-six of 34 patients with radiologically proven RCCs had endocrine disorders. They were 9 boys and 17 girls, with ages ranging from 4.8 to 17.4 years at the time of the diagnosis. Of these, 7 (27%) had idiopathic short stature, 7 (27%) had growth hormone deficiency (GHD), and 12 (46%) had central precocious puberty (CPP). Nineteen of 26 patients (73.1%) showed low signal intensities on T1-weighted images (T1WI) and high signal intensities on T2-weighted images. The incidence of hypointensity on T1WI was higher in the patients with RCCs accompanied by endocrinopathy than in those without endocrinopathy (P=0.033). The treatment outcomes of the patients with CPP and GHD with and without RCCs were similar.

CONCLUSION

CPP and GHD patients with a small RCC (less than 20 mm) expressing cystic magnetic resonance intensity can be managed with medical treatment, although the RCCs need to be closely monitored in radiological studies to observe their growth.

Assessment of pre- and postoperative endocrine function in 94 patients with Rathke's cleft cyst

We reviewed 94 patients with Rathke's cleft cyst (RCC) who were surgically treated at Nippon Medical School Hospital between December 1995 and July 2009 to clarify the effect of surgery on their endocrine function. In our statistical analysis we considered their age and sex, the cyst volume, and preoperative MRI findings. Using simple linear- and multiple regression analysis we evaluated the association between these factors and their preoperative hormone baseline levels. To assess pre- and postoperative anterior pituitary function we subjected the results of various hormone loading tests to the Wilcoxon rank sum test. Surgery improved headache and visual impairment in most patients and elevated PRL levels were significantly normalized after surgery (p = 0.004). However, pre- and postoperative anterior pituitary hormone loading tests revealed that the levels of GH, TSH, LH, and FSH were not improved significantly by surgery. Although the ACTH loading test showed postoperative improvement, the change was not statistically significant. We suggest that RCC patients with headache or visual impairment are good candidates for surgery. We also recommend that patients with hyperprolactinemia and those with ACTH deficiency whose MRI findings reveal low-intensity on T1WI and high-intensity on T2WI are likely to benefit from surgery. In contrast, RCC patients with other hormone dysfunctions do not appear to benefit from surgical intervention.

Spontaneous involution of a Rathke's cleft cyst in a patient with normal cortisol secretion

BACKGROUND

Rathke's cleft cyst (RCC) is a lesion derived from maldeveloped remnants of a dorsal invagination of the stomodeal ectoderm (Rathke's pouch). Although commonly found on autopsy, these lesions rarely become symptomatic during an individual's lifetime. When symptoms occur, they most often include headaches, visual disturbances, and/or varying degrees of hypopituitarism. The natural history remains unclear. The current standard of care includes surgical drainage and biopsy of the cyst wall or surgical resection of symptomatic lesions; however, debate exists regarding the management of asymptomatic lesions. Rare reports of spontaneously resolving RCC can be found in the literature.

CASE DESCRIPTION

We describe the management of a case of RCC in an 8½-year-old girl who presented with a history of growth deceleration since 4 years of age and near-growth arrest since 7 years of age. Her parents also described a tendency towards polydipsia since she was 2 years of age. Endocrine evaluation revealed growth hormone deficiency, central hypothyroidism, and diabetes insipidus, but normal cortisol secretion. The patient experienced no symptoms characteristic of intracranial or sellar mass. Neurologic examination was normal; formal ophthalmologic examination revealed no deficits. The magnetic resonance imaging (MRI) was consistent with RCC. The patient was treated medically for her hormone deficiencies. Over the next year, her sellar mass spontaneously involuted. Twenty-seven months after her initial presentation to our clinic, imaging revealed no sellar mass; the patient remained on hormone replacement therapy.

CONCLUSION

Although the natural history of RCC requires further study, observation with serial MRI may be an acceptable management strategy in the absence of debilitating symptoms.

Rathke cleft cysts: a review of clinical and surgical management

The aim of this paper is to provide a comprehensive review of clinical, imaging, and histopathological features, as well as operative and nonoperative management strategies in patients with Rathke cleft cysts (RCCs). A literature review was performed to identify previous articles that reported surgical and nonsurgical management of RCCs. Rathke cleft cysts are often incidental lesions found in the sellar and suprasellar regions and do not require surgical intervention in the majority of cases. In symptomatic RCCs, the typical clinical presentation includes headache, visual loss, and/or endocrine dysfunction. Visual field testing and endocrine laboratory studies may reveal more subtle deficiencies associated with RCCs. When indicated, the transsphenoidal approach typically offers the least invasive and safest method for treating these lesions. Various surgical strategies including cyst wall resection, intralesional alcohol injection, and sellar floor reconstruction are discussed. Although headache and visual symptoms frequently improve after surgical drainage of RCCs, hypopituitarism and diabetes insipidus are less likely to do so. A subset of more aggressive, atypical RCCs associated with pronounced clinical symptoms and higher recurrence rates is discussed, as well as the possible relationship of these lesions to craniopharyngiomas. Rathke cleft cysts are typically benign, asymptomatic lesions that can be monitored. In selected patients, transsphenoidal surgery provides excellent rates of improvement in clinical symptoms and long-term cyst resolution. Complete cyst wall resection, intraoperative alcohol cauterization, and sellar floor reconstruction in the absence of a CSF leak are not routinely recommended.

Rathke's cleft cysts

Rathke's cleft cysts (RCCs) are benign, sellar and/or suprasellar lesions originating from the remnants of Rathke's pouch. Although a common finding in routine autopsies (12-33% of normal pituitary glands), symptomatic cases are rare and comprise 5-15% of all surgically resected sellar lesions. Small, asymptomatic RCC do not require surgical intervention, and their natural history is not clear. In series of nonoperated presumed RCCs, 26-94% did not progress during follow-up periods up to 9 years. In symptomatic ones, surgery is indicated, aiming to drain the cyst content and safely remove as much of the capsule as possible. Following surgical intervention, headaches and visual field defects improve or resolve in a significant number of patients (40-100% and 33-100%, respectively) and partial hypopituitarism recovers in 14-50%. Data on relapse rates published in the last 15 years are based on variable follow-up periods and show wide variation (between 0% and 33%). The lowest relapse rates have been described in reports with relatively short mean observation periods (<3 years), whereas in those with longer follow-up the relapse rates increase. Most of the relapses occur within 5-6 years, suggesting that follow-up is required for at least 5 years after surgery. Risk factors for relapse include the presence of squamous metaplasia in the cyst wall, cyst size and the presence of inflammation. Long-term sufficiently powered studies aiming to clarify the natural history of asymptomatic RCCs and of those relapsing postoperatively are required.

Bevacizumab-induced tumor calcifications as a surrogate marker of outcome in patients with glioblastoma

Therapy-induced calcifications in glioblastoma are rarely recognized. They may represent regressive changes in the tumor tissue, but their occurrence and possible predictive or prognostic value have not been systematically assessed. The observation of hyperintense lesions on precontrast T1-weighted magnetic resonance images (MRIs) in 2 index patients with glioblastoma after therapy with bevacizumab, subsequently identified as calcifications on computed tomographs (CTs), prompted us to prospectively screen for these radiographic changes. Therefore, 36 patients with recurrent glioblastoma prospectively treated with bevacizumab in an observational trial were examined every 8 weeks by MRI and, if clinically necessary, by CT. In 22 patients (61.1%), T1 hyperintense lesions became apparent after bevacizumab treatment. The median time to detection of these lesions was 55 days. In 14 (63.6%) of 22 patients, CTs were available and confirmed the existence of tumor calcifications. No substantial changes in T1 hyperintense lesions or calcifications were recognized on additional MRI or CT scans. Interestingly, the patients with therapy-induced T1 hyperintense lesions had better durations of progression-free survival than patients without these changes (median, 5.8 vs 3.5 months; P< .001), and the duration of overall survival was also superior (median, 9.7 vs 5.0 months; P= .006). There was a striking correlation between the appearance of therapy-induced T1 hyperintense lesions and overall response to bevacizumab. Therefore, this phenomenon is a rather early and time-limited event during the first weeks of treatment and appears to be response related. In summary, T1 hyperintense lesions are common in patients with glioblastoma who have been exposed to bevacizumab, may represent a novel biomarker of response and outcome, and seem to correspond to tumor calcifications.

Diagnosis and management of adult intracranial neurenteric cysts

BACKGROUND

Intracranial neurenteric cysts are rare, benign lesions of the central nervous system.

OBJECTIVE

To analyze our experience with these lesions and conduct a review of the literature with the aim of identifying a rational approach to diagnosis and management.

METHODS

Seven patients underwent surgical treatment for intracranial neurenteric cysts from July 2000 to December 2008. The general strategy was to perform complete resection whenever possible. The clinical, radiological, operative, and pathological findings of the patients were reviewed retrospectively.

RESULTS

This series included 3 women and 4 men. The age of hospitalized patients ranged from 19 to 55 years, with an average age of 34 years. Headache and dizziness were the most common chief symptoms. The imaging spectrum for these lesions is broad, leading to several preoperative misdiagnoses. All 7 lesions were resected by a far lateral transcondylar or retrosigmoid approach. Total tumor resection was achieved in 3 patients. Four patients presented transient fever postoperatively. All patients were healthy and showed no signs of tumor recurrence at their latest follow-up.

CONCLUSION

Intracranial neurenteric cysts ventral to the brainstem are rare lesions occurring in young adults. These lesions should be considered in the differential diagnosis for intracranial extra-axial cystic lesions anterior to the brainstem. Total surgical resection seems to be the most effective therapeutic method, although radical resection at the risk of impairing the brainstem is not recommended. This benign lesion has a favorable overall prognosis.

Endocrinopathy, Vision, Headache, and Recurrence After Transsphenoidal Surgery for Rathke Cleft Cysts

BACKGROUND

Rathke cleft cyst can enlarge and become symptomatic.

OBJECTIVE

To review the clinical data and results of all patients treated by the senior author for a Rathke cleft cyst.

METHODS

A prospectively maintained surgical database, supplemented with updates from telephone conversations, of all patients presenting to the Barrow Neurological Institute from 1992 to the present was reviewed.

RESULTS

Seventy-three patients (17 males, 56 females; mean age, 40 years; range, 5–80 years) underwent 77 resections. The mean length of follow-up was 27 months (range, 0–129 months). Presenting symptoms included headache (75%), followed by endocrinopathy (49%), and visual symptoms (39%). Preoperative chiasmopathy resolved in 75% and improved in 21% of the patients. Patients' preoperative endocrinopathy resolved at various rates, depending on the specific axis (29%–100%). Endocrinopathies were more likely to resolve in females than males. New postoperative endocrinopathies also occurred (0–8%). Headache resolved (68%) or improved (21%) in most patients. No patient had worsened headaches. Eight patients had a recurrence, 4 of whom underwent reoperation. The presence of squamous metaplasia was the only predictor of recurrence.

CONCLUSION

Surgical fenestration and/or resection of Rathke cleft cyst via the transsphenoidal approach are a rational choice for surgical management of these lesions when symptomatic. In most cases, visual symptoms and headache can be expected to improve. New persistent endocrine deficits can be expected in a small percentage of patients, but preexisting endocrinopathies resolve in many patients.

Craniopharyngioma and other cystic epithelial lesions of the sellar region: a review of clinical, imaging, and histopathological relationships

Object

Cystic epithelial masses of the sellar and parasellar region may be difficult to differentiate on a clinical, imaging, or even histopathological basis. The authors review the developmental relationships and differentiating features of various epithelial lesions of the sellar region.

Methods

The authors performed a review of the literature to identify previous studies describing the etiological relationships and differentiating features of various cystic sellar lesions, including craniopharyngioma (CP), Rathke cleft cyst, xanthogranuloma, and dermoid and epidermoid cysts.

Results

There is significant evidence in the literature to support a common ectodermal origin of selected sellar and suprasellar cystic lesions, which may account for the overlap of features and transitional states observed in some cases. Research obtained from animal studies and reports of transitional cystic epithelial masses or lesions crossing over from typical to more aggressive pathological subtypes have collectively provided a solid foundation for this theory. Histological features that signify transitional entities beyond simple benign Rathke cleft cysts include squamous metaplasia, stratified squamous epithelium, and ciliated or mucinous goblet cells in squamous-papillary CPs. Several studies have identified key clinical, imaging, and histopathological features that can be used in the differentiation of these lesions.

Conclusions

The pattern of embryological formation of the hypothalamic-pituitary axis plays a major role in its propensity for developing cystic epithelial lesions. Subsequent inflammatory, metaplastic, and neoplastic processes may promote further progression along the pathological continuum, ranging from benign epithelial cysts to aggressive neoplastic cystic CPs. Selected clinical, imaging, and histopathological features can be used collectively to help differentiate these lesions and assign a formal diagnosis, thus accurately guiding further treatment.