Imaging of sellar and parasellar pathology

Biological effective dose as a predictor of local tumor control in stereotactic radiosurgery treated parasellar meningioma patients

INTRODUCTION

The radio-surgical literature increasingly uses biological effective dose (BED) as a replacement for absorbed dose to analyze outcome of stereotactic radiosurgery (SRS). There are as yet no studies which specifically investigate the association of BED to local tumor control in para-sellar meningioma.

METHODS

we did a retrospective analysis of patients underwent stereotactic radiosurgery (SRS) for para-sellar meningioma during the period of 1995-2022. Demographic, clinical, SRS parameters, and outcome data were collected. The target margin BED with and without a model for sub-lethal repair was calculated, as well as a ratio of BED at the target margin to the absorbed dose at the target margin. Factors related to local control were further analyzed.

RESULTS

The study was comprised of 91 patients, 20 (22.0%) and 71 (78.0%) of whom were male and female, respectively. The median age was 55.0 (interquartile range Q1, Q3:47.5,65.5years). 34 (37%) patients had a resection of their meningioma prior to SRS. The median interval from SRS to last clinical follow up or progression was 89 months. 13 (14.3%) patients were found to have progression. 3-, 5- and 10-years local tumor control were 98%, 92% and 77%, respectively. In cox univariate analysis, the following factors were significant: Number of prior surgical resections (Hazard Ratio [HR] = 1.82, 95% CI = 1.08-3.05, p = 0.024), BED (HR = 0.96, 95% CI = 0.92-1.00, p = 0.03), and BED/margin (HR = 0.44, 95% CI = 0.21-0.92, p = 0.028). A BED threshold above 68 Gy was associated significantly with tumor control (P = 0.04).

CONCLUSION

BED and BED /margin absorbed dose ratio can be predictors of local control after SRS in parasellar meningioma. Optimizing the BED above 68Gy2.47 may afford better long-term tumor control.

A dual-branch hybrid dilated CNN model for the AI-assisted segmentation of meningiomas in MR images

BACKGROUND AND OBJECTIVE

Treatment for meningiomas usually includes surgical removal, radiation therapy, and chemotherapy. Accurate segmentation of tumors significantly facilitates complete surgical resection and precise radiotherapy, thereby improving patient survival. In this paper, a deep learning model is constructed for magnetic resonance T1-weighted Contrast Enhancement (T1CE) images to develop an automatic processing scheme for accurate tumor segmentation.

METHODS

In this paper, a novel Convolutional Neural Network (CNN) model is proposed for the accurate meningioma segmentation in MR images. It can extract fused features in multi-scale receptive fields of the same feature map based on MR image characteristics of meningiomas. The attention mechanism is added as a helpful addition to the model to optimize the feature information transmission.

RESULTS AND CONCLUSIONS

The results were evaluated on two internal testing sets and one external testing set. Mean Dice Similarity Coefficient (DSC) values of 0.886, 0.851, and 0.874 are demonstrated, respectively. In this paper, a deep learning approach is proposed to segment tumors in T1CE images. Multi-center testing sets validated the effectiveness and generalization of the method. The proposed model demonstrates state-of-the-art tumor segmentation performance.

Predictive Factors of Favorable Visual Outcomes After Surgery of Tuberculum Sellae Meningiomas: A Multicenter Retrospective Cohort Study

BACKGROUND

Because of their proximity to the visual structures, tuberculum sellae meningiomas are frequently revealed by ophthalmologic impairment. The goal of surgery is gross total resection and improvement of visual function. The purpose of the present study was to identify the predictors of favorable visual outcomes after surgery of tuberculum sellae meningioma.

METHODS

We retrospectively collected tuberculum sellae meningiomas treated at 2 neurosurgical centers from 2010 to 2020. We collected the clinical, imaging and surgical data and analyzed their effects on the visual outcome. A favorable visual outcome was defined as an increase in visual acuity of ≥0.2 point and/or an increase of >25% of the visual field or complete recovery.

RESULTS

A total of 50 patients were included. At 4 months after surgery, 30 patients (60%) had experienced visual improvement. The predictors of a favorable visual outcome were a symptom duration of <6 months, preoperative visual acuity >0.5, a smaller tumor size, and tumor with T2-weighted/fluid attenuated inversion recovery hypersignal on magnetic resonance imaging. During surgery, a soft tumor and a clear brain-tumor interface were associated with favorable visual outcomes. Preoperative optic coherence tomography measurements of the retinal nerve fiber layer thickness >80 μM and ganglion cell complex thickness >70 μM were also associated with a better ophthalmologic outcome.

CONCLUSIONS

In tuberculum sellae meningiomas, rapid surgical treatment must be performed to optimize vision improvement. A hyperintense lesion on T2-weighted/fluid attenuated inversion recovery magnetic resonance imaging and minor vision impairment at the initial ophthalmologic presentation might give hope for a favorable outcome. Performing optic coherence tomography measurements before surgery could clarify patients' expectations regarding their recovery.

Ectopic sphenoid sinus pituitary adenoma masquerading as metastatic head and neck cancer

A 68-year-old Chinese man was found to have a lobular mass in the sphenoid sinus which extended to the clivus and the roof of the nasopharynx on a staging MRI scan performed for his high-grade parotid salivary duct carcinoma. Further positron emission tomography scan showed that this lesion was fluorodeoxyglucose (FDG) avid. This proved to be a diagnostic dilemma. The patient underwent a total parotidectomy, left selective neck dissection and a transphenoidal biopsy of his nasal lesion. Final histology revealed that this lesion was a synchronous ectopic sphenoid sinus pituitary adenoma (ESSPA). Initial differential diagnoses that were considered included a chordoma, metastatic carcinoma and nasopharyngeal carcinoma. However, an important differential with a neoplastic appearance and a tendency for positive FDG uptake is an ESSPA. It requires dedicated immunohistochemical staining to diagnose, and its mainstay of treatment is surgical excision.

Suprasellar Meningiomas: An Experience of Four Cases With Brief Review of Literature

Suprasellar meningiomas make a relevant differential when it comes to sellar/suprasellar masses. The most common pathology in this location is pituitary adenomas. It is imperative to differentiate the two entities based on imaging as the clinical picture, and sometimes the biochemical profile can show significant overlap. It is also essential for the neurosurgeons to have a preoperative diagnosis as the behavior of both tumors is different. This piece will give a pictorial review of the imaging features of suprasellar meningiomas, in patients who presented to us with sellar/suprasellar masses. The aim is to help the radiologists as well as fellow clinicians to diagnose this entity with confidence based on imaging.

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.

Neuroimaging of the Pituitary Gland: Practical Anatomy and Pathology

The pituitary gland is a small endocrine organ located within the sella turcica. Various pathologic conditions affect the pituitary gland and produce endocrinologic and neurologic abnormalities. The most common lesion of the pituitary gland is the adenoma, a benign neoplasm. Dedicated MR imaging of the pituitary is radiologic study of choice for evaluating pituitary gland and central skull region. Computed tomography is complimentary and allows for identification of calcification and adjacent abnormalities of the osseous skull base. This review emphasizes basic anatomy, current imaging techniques, and highlights the spectrum of pathologic conditions that affect the pituitary gland and sellar region.

Parasellar meningioma presenting by stroke and bilateral occlusion of the internal carotid arteries: A case report

Cerebrovascular stroke caused by skull base meningioma has been rarely reported. A 30-year-old male presented (April 2015) with acute right-sided hemiplegia. His brain neuroimaging (computerized tomography and magnetic resonance imaging) showed left ischemic infarction in the territory of middle cerebral artery. Magnetic resonance imaging also showed a right parasellar solid lesion which extended to the right basisphenoid and cavernous sinus and attenuated the right internal carotid artery. It also had left smaller parasellar extension. The lesion enhanced uniformly and strongly following gadolinium injection. Digital subtraction angiography using selective catheterization of both common carotid and left vertebral arteries (07/13/2015) showed occlusion of both internal carotid arteries and faint visualization of left terminal internal carotid artery and its bifurcation. The right internal carotid artery and its branches were not visualized. Left vertebral injection showed prominent left vertebral and basilar arteries and filling of both internal carotid arteries through posterior communicating arteries. A faint blush of contrast was noticed at the parasellar region coinciding with meningioma. The patient received three treatment sessions of gamma knife radiosurgery as follow: 20 cc of the tumor was treated with 12 Gy (15 August 2015), 1.7 cc was treated with 10 Gy (31 January 2016), and 2.5 cc was treated with 11 Gy (13 August 2016) which resulted in complete clinical recovery and tumor size reduction. Compensation from the posterior communicating and external carotid arteries might explain the complete clinical recovery after tumor size reduction with gamma knife radiosurgery.

Parasellar Meningiomas

Parasellar spaces remain particularly singular, comprising the most important neurovascular structures such as the internal carotid artery and optic, oculomotor, and trigeminal nerves. Meningiomas are one of the most frequent tumors arising from parasellar spaces. In this location, meningiomas remain mostly benign tumors with WHO grade I and a meningothelial subtype. Progestin intake should be investigated and leads mostly to conservative strategies. In the case of benign nonsymptomatic tumors, observation should be proposed. Tumor growth will lead to the proposition of surgery or radiosurgery. In the case of an uncertain diagnosis and an aggressive pattern, a precise diagnosis is required. For cavernous sinus and Meckel's cave lesions, complete removal is rarely considered, leading to the proposition of an endoscopic endonasal or transcranial biopsy. Optic nerve decompression could also be proposed via these approaches. A case-by-case discussion about the best approach is recommended. A transcranial approach remains necessary for tumor removal in most cases. Vascular injury could lead to severe complications. Cerebrospinal fluid leakage, meningitis, venous sacrifice, visual impairment, and cranial nerve palsies are more frequent complications. Pituitary dysfunctions are rare in preoperative assessment and in postoperative follow-up but should be assessed in the case of meningiomas located close to the pituitary axis. Long-term follow-up is required given the frequent incomplete tumor removal and the risk of delayed recurrence. Radiosurgery is relevant for small and well-limited meningiomas or intra-cavernous sinus postoperative residue, whereas radiation therapy and proton beam therapy are indicated for large, extended, nonoperable meningiomas. The place of the peptide receptor radionuclide therapyneeds to be defined. Targeted therapy should be considered in rare, recurrent, and aggressive parasellar meningiomas.

Ectopic Pituitary Adenoma Presenting as a Clival Mass

Pituitary adenomas are well described in the literature and are frequently observed and treated in clinical practice by neurosurgeons. On the other hand, ectopic adenomas are a diagnostic enigma; a good understanding of anatomy and radiological characteristics is crucial for the successful management of such pathologies. In this paper, we describe the case of a 77-year-old woman who presented with a clival mass invading the left cavernous sinus; we also discuss the associated diagnostic techniques, approaches, imaging options, and characteristics.

Newly Diagnosed Sellar Tumors in Patients with Cancer: A Diagnostic Challenge and Management Dilemma

BACKGROUND

The use of combined positron emission tomography/computed tomography for staging in patients with cancer and the widespread use of magnetic resonance imaging has led to increased detection of incidental sellar masses. The imaging findings can be suggestive of a benign pituitary tumor, but metastasis can never be completely ruled out with noninvasive work-up. Appropriate diagnosis of sellar masses is critical, as the treatment paradigm might change in the presence of a pituitary metastasis. Definitive tissue diagnosis might prevent unnecessary radiotherapy to the skull base or the need for systemic treatment when benign pituitary disease is confirmed.

METHODS

A retrospective chart review from 2010 to 2015 of all patients with recently diagnosed cancer and undergoing surgery for sellar region masses was performed.

RESULTS

There were 9 patients (3 female and 6 male) identified. Lung cancer was the primary condition in 4 patients; the remaining 5 patients had breast cancer, follicular thyroid cancer, cutaneous melanoma, colorectal carcinoma, and renal cell carcinoma. On final pathology, the sellar mass was a benign pituitary adenoma in 5 patients, metastatic cancer in 3 patients, and a granular cell tumor in 1 patient.

CONCLUSIONS

Surgical resection of a sellar mass in patients with known cancer helps in the definitive diagnosis, relieves compressive symptoms, and avoids unnecessary empiric radiotherapy in cases of confirmed benign pituitary disease.

Pituitary apoplexy presenting as a peripheral rim enhancing parasellar mass lesion with dural enhancement along the tentorium

Pituitary apoplexy is a potentially life-threatening clinical condition caused by rapid enlargement of a pituitary adenoma because of haemorrhage or infarction. The clinical features are typically acute in onset. We report an interesting case of 25-year-old man with complaints of sudden onset of headache and ophthalmoplegia in the right eye one month previously. He had ptosis and complete ophthalmoplegia in the right eye with visual acuity 6/24 and 6/12. Imaging showed a peripheral rim-enhancing mass lesion in the right parasellar and cavernous sinus with a dural tail. He underwent craniotomy and subtotal excision of the lesion. Histopathology was reported as pituitary apoplexy. Hormonal analysis was within normal limits. At two years of follow-up he had complete resolution of ophthalmoplegia and improvement in his vision. It is very uncommon to see pituitary apoplexy evolved in right parasellar region presenting as peripheral rim-enhancing mass lesion.

Giant multi-compartmental suprasellar Rathke's cleft cyst with restriction on diffusion weighted images

Rathke's cleft cysts are congenital lesions seen in sellar-suprasellar regions. We report a case of giant Rathke cyst in a 43-year-old patient with multi-compartmental involvement who presented with seizures with almost normal visual acuity. We discuss radiological and pathological features of various differential diagnoses for the giant suprasellar Rathke's cyst.

Current imaging techniques for the diagnosis of pituitary adenoma

Stepwise improvements in the imaging of pituitary adenomas in the last 100 years have had a tremendous impact on patient care. Pituitary tumors are now diagnosed earlier in the time course of the disease, improving chances of endocrine and visual recovery. There is improved pre-surgical planning due to a better understanding of the investment of the tumor around important surrounding parasellar structures. Approaches to tumors are now safer due to stereotactic navigation and residual disease can be radiographically followed for a lifetime and treated prior to irreversible neurological damage. Furthermore, adjuvant radiotherapy can be more precisely delivered to the tumor bed with the aid of higher resolution images. Thanks to these incremental improvements previously formidable macroadenomas, which carried a high risk for morbidity and residual disease, can now be treated safely and effectively. Here, we review modern imaging modalities used to diagnose pituitary adenomas, and identify areas for further improvement.

Clinical features of sellar and suprasellar meningiomas

Meningiomas account for about 1% of sellar masses. Although they can mimic pituitary adenomas, they are more vascularized and invasive. To gain insights that would enhance our ability to establish a pre-surgical diagnosis of meningioma, we performed a retrospective study of these tumors. Query of the surgical pathology database identified 1,516 meningiomas operated at out institution between January 2000 and May 2012. Cases were matched to the radiology database to identify a strictly defined sellar and/or suprasellar location. We identified 57 meningiomas. F:M ratio was 6:1. The mean age was 52 years (median 50, range 30-78). The most common symptoms were visual disturbance (58%), headache (16%) and incidental finding (12%). The mean duration of symptoms was 13 months. Hyperprolactinemia was found in 36%, with mean value of 51.6 ng/ml (median 41.8, range 22.5-132). Mean maximal diameter was 2.9 cm (median 2.7, range 0.9-6.8), and most tumors enhanced homogeneously on MRI after gadolinium. A "dural tail" sign was reported in a third. The radiologist reported "likely meningioma" in 65%, "possible meningioma" in 8.7%, and pituitary adenoma in 11%. After surgery, visual disturbances improved in most patients (80%) but headache only in 7%. Post-operative complications at 1 and 3 months occurred 38.6 and 33.3% respectively. There was no mortality. Sellar/suprasellar meningiomas represent 4% of all meningiomas, and have a particularly high female predominance. The diagnosis is suggested by the radiologist in approximately 2/3 of the cases. An improved method to differentiate preoperatively these tumors from adenomas would be desirable.

Anatomical analysis on the lateral bone window of the sella turcica: a study on 530 adult dry skull base specimens

OBJECTIVE

To investigate the morphometric characteristics of the lateral bone window (LBW) of the sella turica.

METHODS

A descriptive anatomical study of LBW was performed in 530 cases of dry skull base specimens with relatively complete sella turcica. Detailed morphometric characteristics such as dimensions and classification of the LBW was studied. All data analysis was performed using SPSS 17.0 statistical software.

RESULTS

LBW is located in the lateral bony structures of sella turcica. The mean area sizes of the LBW were 75.99 ± 25.81 mm(2) (left) and 76.00 ± 25.53 mm(2) (right). There was no significant difference and there was a ​​good positive correlation between bilateral areas of the LBWs. The area size of the LBWs is graded as follows: Grade A (< 60 mm(2)), B (60~90 mm(2)) and C (> 90 mm(2)). LBW morphology was typed as follows: Type I, II, III, IV. And Tpye III includes Type IIIa and IIIb; Type IV includes Type IVa, IVb, IVc, IVd.

CONCLUSIONS

The lateral bone window of sella turcica is an important structure located between pituiary fossa and parasellar region. The morphological measurements and variations of LBW in this study will provide preliminary data for further anatomical study of sella turcica. Moreover, knowing detailed anatomy of this region is essential for neurosurgeons who make surgery on cranial base or for teaching about the sella turcica in the neuroanatomy lab.

Magnetic resonance imaging validation of pituitary gland compression and distortion by typical sellar pathology

OBJECT

Identification of the normal pituitary gland is an important component of presurgical planning, defining many aspects of the surgical approach and facilitating normal gland preservation. Magnetic resonance imaging is a proven imaging modality for optimal soft-tissue contrast discrimination in the brain. This study is designed to validate the accuracy of localization of the normal pituitary gland with MRI in a cohort of surgical patients with pituitary mass lesions, and to evaluate for correlation between presurgical pituitary hormone values and pituitary gland characteristics on neuroimaging.

METHODS

Fifty-eight consecutive patients with pituitary mass lesions were included in the study. Anterior pituitary hormone levels were measured preoperatively in all patients. Video recordings from the endoscopic or microscopic surgical procedures were available for evaluation in 47 cases. Intraoperative identification of the normal gland was possible in 43 of 58 cases. Retrospective MR images were reviewed in a blinded fashion for the 43 cases, emphasizing the position of the normal gland and the extent of compression and displacement by the lesion.

RESULTS

There was excellent agreement between imaging and surgery in 84% of the cases for normal gland localization, and in 70% for compression or noncompression of the normal gland. There was no consistent correlation between preoperative pituitary dysfunction and pituitary gland localization on imaging, gland identification during surgery, or pituitary gland compression.

CONCLUSIONS

Magnetic resonance imaging proved to be accurate in identifying the normal gland in patients with pituitary mass lesions, and was useful for preoperative surgical planning.

Sellar meningiomas: an endocrinologic perspective

To review the clinical manifestations and outcomes of those with sellar meningiomas treated surgically at Mayo Clinic between 1975 and 2003. This is a retrospective chart and pathology review of 17 patients with a diagnosis of purely or largely intrasellar meningiomas treated surgically at our institution. Data in regards to presentation, endocrine hormonal status, surgical approach, pathology findings, outcome and adjunctive treatment were abstracted from the medical records. The majority of patients present with visual disturbances. All 17 tumors were WHO grade I. Surgical cure was achieved in 53 % after initial surgery. Postsurgical hypopituitarism occurred with high frequency. A substantial proportion of patients required subsequent surgical intervention or adjunctive treatment with external beam radiation. Sellar meningiomas are technically challenging and carry a high risk for visual disturbance and pituitary hormonal abnormalities. Many patients experience persistent disease requiring further intervention. These patients require long-term follow-up for evaluation of recurrence or development of new pituitary hormonal insufficiencies.

Clinical features of nonpituitary sellar lesions in a large surgical series

CONTEXT

Pituitary adenomas are the most common lesions in the sellar region, but other pathologies need to be considered in the differential diagnosis.

OBJECTIVE

To assess the prevalence of unusual sellar masses in a large series of patients and identify clinicopathological factors that may aid the pre-operative diagnosis.

DESIGN

Retrospective case series.

PATIENTS

We analysed the records of 1469 transsphenoidal procedures performed between 1998 and 2009. One hundred sixteen cases (7·9%) were not pituitary adenomas.

MEASUREMENTS

Final pathological diagnosis.

RESULTS

One hundred sixteen patients (45 men, 71 women; mean age (±SD): 45 ± 17 years) with nonadenomatous lesions were divided into four major aetiological groups: cystic lesions (CYS) (53%); benign neoplasms (BEN) (22%); malignancies (MAL) (16%) and inflammatory lesions (INF) (9%). Rathke's cysts, the most common lesions, represented 42% of all cases. Twenty-five per cent of malignant lesions were metastases, and some of the MAL (e.g., fibrosarcoma, lung metastasis) had a radiographical appearance suggestive of a pituitary adenoma. The most common presenting symptoms were visual field impairment (51%) and headache (34%). Pre-operative pituitary dysfunction was present in 58% of cases, with hyperprolactinaemia (35%), hypogonadism (23%) and hypocortisolism (23%) found most frequently. Postoperative resolution of headache and visual symptoms occurred in 63% and 65% of patients, respectively. Hyperprolactinaemia resolved in 77% of cases.

CONCLUSIONS

A substantial minority of sellar masses are not pituitary adenomas. While they frequently present with the symptoms, hormone abnormalities and radiographical appearance typical of pituitary tumours, the possibility of a nonadenomatous lesion needs to be considered in the differential diagnosis.

Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings

Ectopic pituitary adenomas (EPAs) are rare lesions. The purpose of this study was to describe the CT and MRI features of sphenoid sinus EPAs. Eight patients with histology-proven EPAs in the sphenoid sinus, all of whom underwent CT and MRI, were reviewed retrospectively. The following imaging features were analysed: (i) size, (ii) margin, (iii) CT attenuation characteristics and (iv) MRI signal intensity. In addition, the involvement of adjacent structures and the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analysed. All EPAs had well-defined margins and showed no relationship to the intrasellar pituitary gland. The mean size was 28 mm (range, 20-46 mm). On non-enhanced CT, the lesions appeared isodense to grey matter in 7 (88%) patients and hypodense in 1 (12%) patient. Only two patients underwent post-contrast CT, and they showed moderate enhancement. On T1 weighted images, EPAs appeared isointense in 6 (75%) patients and hypointense in 2 (25%). On T2 weighted images, the lesions appeared hyperintense in 2 (25%) patients and isointense in 6 (75%). EPAs showed mild to moderate heterogeneous contrast enhancement and exhibited a cribriform-like appearance. Two patients underwent DCE MRI; the TIC showed a rapidly enhancing and slow washout pattern. The following features were also seen: an empty sella, bone changes and involvement of the cavernous sinus (5 patients; 62.5%). In conclusion, a high index of suspicion for EPA and a familiarity with the imaging findings may help to diagnose this rare entity accurately.

Collision tumors of the sella: craniopharyngioma and silent pituitary adenoma subtype 3: case report

Collision tumors of the sella turcica are rare and consist mainly of more than one type of pituitary adenoma, usually a corticotropin- and a prolactin-producing adenoma. The association of a craniopharyngioma and a pituitary adenoma is rare. Herein, we report the first case of an association between craniopharyngioma and silent pituitary adenoma subtype 3. It involved a 12-year-old boy who underwent a frontal craniotomy with surgical removal of a calcified sellar tumor. Histology revealed an adamantinomatous craniopharyngioma; however, by electron microscopy, there was conclusive evidence of adenoma cells showing the ultrastructural features of silent pituitary adenoma subtype 3. Endocrine and neuroimaging as well as detailed immunohistochemical and ultrastructural studies were undertaken. The literature is also reviewed.

[Sellar tumors]

Because of the complex anatomy, examination of the sella turcica and hypophysis needs a dedicated MR sequence protocol. Not every sellar lesion is a pituitary adenoma. Thus, this review article summarizes the most frequently encountered intra-, supra-, and parasellar tumors and lesions. Differential diagnoses comprise besides adenoma among others craniopharyngioma, meningioma, glioma, germinoma, hamartoma, aneurysm, trigeminal schwannoma, pituitary carcinoma, chordoma, metastasis, infection, and empty sella. Characteristic imaging findings are presented and correlated to micro- and macro-pathology.

Brain MRI: tumor evaluation

The designation "brain tumors" is commonly applied to a wide variety of intracranial mass lesions that are distinct in their location, biology, treatment, and prognosis. Since many of these lesions do not arise from brain parenchyma, the more appropriate term would be "intracranial tumors." The term "tumor" is used to include both neoplastic and non-neoplastic mass lesions, and should be considered in its broadest sense to simply indicate a space-occupying mass. This review describes an imaging-based approach for evaluating intracranial tumors. Conventional MRI is discussed in the setting of a regional classification system. This system provides a framework for analysis, and imaging clues can then be applied to narrow the differential possibilities. Emphasis is placed on advanced MRI techniques and their utility for deciphering common diagnostic problems.

Parasellar tumors: suprasellar and cavernous sinuses

This article will review the presentation and imaging appearance of tumors affecting the area around the pituitary gland. For convenience, the lesions will be discussed in order of the regions they usually affect. For example, lesions affecting the suprasellar region include craniopharyngiomas, optic or hypothalamic gliomas, germ cell tumors, epidermoids, dermoids, hamartomas, lipomas, and choristomas. Tumors that commonly affect the parasellar cavernous sinus include schwannomas and meningiomas. Tumors like chordomas may arise in the sphenoid bone or clivus and affect the sella. Metastasis, meningiomas and aneurysms may involve any area around the sella. For a detailed discussion of normal anatomy and imaging protocols, see the first article of this monograph.

Thin-slice three-dimensional gradient-echo magnetic resonance imaging of the pituitary gland in healthy dogs

OBJECTIVE

To evaluate thin-slice 3-dimensional gradient-echo (GE) magnetic resonance imaging (MRI) of the pituitary gland in healthy dogs.

ANIMALS

11 healthy dogs.

PROCEDURES

By use of a 0.2-Tesla open magnet, MRI of the skull was performed with T1-weighted GE sequences and various protocols with variations in imaging plane, slice thickness, and flip angle before and after administration of contrast medium; multiplanar reconstructions were made. The pituitary region was subjectively assessed, and its dimensions were measured. Image quality was determined by calculation of contrast-to-noise and signal-to-noise ratios.

RESULTS

Best-detailed images were obtained with a T1-weighted GE sequence with 1-mm slice thickness and 30 degrees flip angle before and after administration of contrast medium. Images with flip angles > 50 degrees were of poor quality. Quality of multiplanar reconstruction images with 1-mm slices was better than with 2-mm slices. The bright signal was best seen without contrast medium. With contrast medium, the dorsal border of the pituitary gland was clearly delineated, but lateral borders were more difficult to discern.

CONCLUSIONS AND CLINICAL RELEVANCE

MRI of the canine pituitary gland with a 0.2-Tesla open magnet should include a T1-weighted GE sequence with 1-mm slice thickness and flip angle of 30 degrees before and after administration of contrast medium. The neurohypophysis was best visualized without contrast medium. The MRI examination permitted differentiation between the pituitary gland and surrounding structures.

Optic pathways tuberculoma mimicking glioma: case report

BACKGROUND

Optochiasmatic tuberculomas are very rare lesions. They can occur with concomitant tuberculous meningitis, and pulmonary tuberculosis or as the only manifestation of the disease. The authors present a case of optic pathways tuberculoma with radiologic appearance simulating an optic pathways glioma.

CASE DESCRIPTION

We report a case of a 20-year-old man with mental retardation due to anoxic encephalopathy who developed a sudden bilateral amaurosis. He also presented with diabetes insipidus, panhypopituitarism, right proptosis, and chemosis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed an enhancing lesion in the optochiasmatic region extending to both optic nerves, with a mass in the right orbit, mimicking an optic pathways glioma. There was no other evidence of systemic involvement of the tuberculosis. The lesion was explored through a right pterional transylvian approach with opening of the optic canal and orbital roof, and a biopsy and an internal decompression were performed. Histopathological studies demonstrated a granulomatous lesion with central caseous necrosis with acid-fast bacilli. The patient improved after treatment with tuberculostatic drugs, but vision recovery could not be achieved.

CONCLUSIONS

Visual compromise in tuberculosis is associated with hydrocephalus, optical neuritis or tuberculomas involving the optic pathways. Reviewing the literature on tuberculomas of the optochiasmatic area, we could not find any other case with such extensive involvement of the optic pathways that was radiologically suggestive of an infiltrating glioma. Histopathological studies remain crucial in the diagnosis of intrinsic expansive processes of the optochiasmatic region.

Morphological changes on MR imaging of the normal pituitary gland related to age and sex: main emphasis on pubescent females

The pituitary gland of 300 individuals (ages: 3-85 years; 101 males and 199 females) with no pituitary gland related symptoms were studied using a 1.5-T superconductive magnetic resonance imaging (MRI) unit. The focus of the study was on morphological changes at puberty in females. Among three parameters related to pituitary size, height changed the most remarkably in relation to age and sex, reaching a peak towards the first half of the third decade of a women's life. However, the convex shaped upper pituitary surface was most often recognized in the first half of the second decade. Moreover, in children and adolescents, this shape was predominantly shown by females. A coronal deviation of the stalk attachment to the pituitary gland, which might be indicative of pituitary tumour, was most frequently observed in individuals less than 20 years of age and those over 50. The pituitary size and shape varied, especially with respect to height, likely in response to changes in the hormonal environment. Hence, care must be taken when evaluating the size of the pituitary gland by MRI, especially in the diagnosis of pituitary tumour.

[Hormonal dysfunction of nonpituitary lesions from midline and perisellar area]

OBJECTIVE

To analyse clinical and/or laboratorial preoperative hormonal dysfunction, of the nonpituitary intracranial lesions from midline and parasellar area.

METHOD

Forty-four patients were evaluated with nonpituitary intracranial lesions, who had images studies (computed tomography or magnetic resonance) and preoperative basal hormonal level; 16 had preoperative hypothalamus-hypophysial function tests (megatests). These patients were divided in two groups. Group I - 34 lesions from midline: 11 craniopharyngiomas, 8 meningiomas, 3 germinomas, 3 tumors of sphenoid sinus, 2 empty sella syndrome, 2 pylocitic astrocytomas, 1 giant aneurysm, 2 mucoceles, 1 III ventricle diverticulum and 1 Rathke's cleft cyst; Group II - 10 lesions from parasellar area: 9 meningiomas and 1 giant aneurysm.

RESULTS

In group I, 25/34 (73.5%) patients showed laboratorial hormonal deficit (14 without clinical manifestations) 18/34 (52.9%) hyperprolactinemia (5 with galactorreia) and 8 (53.3%) showed growth hormone deficiency in 15 megatests available in this group; 3 (8.8 %) patients presented central diabetes insipidus (CDI). In group II, 6/10 (60%) patients showed laboratorial hormonal deficit (5 without clinical manifestations), 1 (10%) hyperprolactinemia and 1 growth hormone deficiency (single megatest realized in this group); no patient had preoperative CID.

CONCLUSIONS

The presence of nonspecific or poorly valorized clinical manifestations, does not indicate absence of hormonal dysfunction; in this present serie, 19/38 (50%) patients with laboratorial abnormalities, didn't show clinical manifestations. Hormonal dysfunction is frequent in sellar and perisellar nonpituitary lesions, specially involving midline.