Xanthogranuloma of the intrasellar region presenting in pituitary dysfunction: a case report

Intrasellar xanthogranuloma mimicking macroadenoma

Intracranial xanthogranulomas (XGs) have been found at various sites, but xanthogranuloma of the sellar region is extremely rare. We report about a case of sellar XG in a 34-year-old female. Magnetic resonance imaging showed a solid-cystic mass located at the sella turcica. The cystic component was hyperintense on the T1-weighted image (WI) and T2WI. The solid component was hyperintense on T1WI and hypointense on T2WI. There was peripheral enhancement after gadolinium administration. The diagnosis of cystic macroadenoma was considered before surgery. Final diagnosis of XG was confirmed by histopathological examination after surgical resection. Gross total resection of the lesion was achieved using the microscope through endoscopic endonasal transsphenoidal approach. The patient had a good outcome and no symptom of diabetes insipidus, hormonal evaluation did not show any alterations compatible with hypopituitarism and prolactin levels were normal XG should receive diagnostic consideration for the sellar mass lesions with cystic components hyperintense on T1WI and T2WI, solid components hyperintense on T1WI and hypointense on T2WI, and CT without evidence of calcifications. It is important to consider the possibility of XG when pertinent, as it facilitates a proper surgical approach strategy.

Inflammatory and Infectious Disorders in Endocrine Pathology

A variety of inflammatory conditions may directly involve the endocrine glands, leading to endocrine dysfunction that can cause severe consequences on patients' health, if left untreated. Inflammation of the endocrine system may be caused by either infectious agents or other mechanisms, including autoimmune and other immune-mediated processes. Not infrequently, inflammatory and infectious diseases may appear as tumor-like lesions of endocrine organs and simulate neoplastic processes. These diseases may be clinically under-recognized and not infrequently the diagnosis is suggested on pathological samples. Thus, the pathologist should be aware of the basic principles of their pathogenesis, as well as of their morphological features, clinicopathological correlates, and differential diagnosis. Interestingly, several systemic inflammatory conditions show a peculiar tropism to the endocrine system as a whole. In turn, organ-specific inflammatory disorders are observed in endocrine glands. This review will focus on the morphological aspects and clinicopathological features of infectious diseases, autoimmune disorders, drug-induced inflammatory reactions, IgG4-related disease, and other inflammatory disorders involving the endocrine system. A mixed entity-based and organ-based approach will be used, with the aim to provide the practicing pathologist with a comprehensive and practical guide to the diagnosis of infectious and inflammatory disorders of the endocrine system.

Xanthogranuloma of the sellar region: a systematic review

Knowledge of xanthogranuloma (XG) of the sellar region comes from short series or single cases. We performed a systematic review, using the PubMed, Web of Science, Embase, Scopus, eLibrary, and BIOSIS Preview databases, of all cases reported from 2000 to the present. We also describe one unreported patient treated in our institution. A search of the literature revealed that of 71 patients 50.7% were male and that mean age at diagnosis was 34.7 ± 19.2 years old. Median time from clinical onset until diagnosis was 7 (3-21) months. Hypopituitarism (70.4%), visual disorders (64.7%), headache (53.5%), and polyuria-polydipsia (28.2%) were the most common symptoms. On MRI, median tumor size was 20 (16-29) mm, while 71.8% were sellar/suprasellar and less frequently exclusively suprasellar (15.5%) or sellar (12.7%). On T1-weighted imaging, XG was hyperintense in 76.3% of patients, while it showed variable appearance on T2-weighted imaging. The tumor showed cystic features in 50.7%, gadolinium enhancement in 45.1%, and calcification in 22.5% of patients. All patients underwent surgery (77.4% transphenoidal approach and 18.3% craniotomy), with hypopituitarism (56.4%), diabetes insipidus (34.5%), and visual defects (7.3%) being the most common complications. Total/subtotal resection was achieved in 93.5%, while the tumor was partially removed in 6.6%. Median follow-up was 24 (6-55) months and no tumor recurrence or remnant growth was reported in 97.5% of cases. In conclusion, XG affects the younger population, manifested by hormonal deficit and mass effect symptoms. Surgery is safe and offers excellent outcomes, though hypopituitarism is frequent post-surgery. Tumor recurrence or remnant growth is rare and radiological surveillance is a good option for patients with remnant lesions.

Xanthogranuloma of the Sellar Region: A Comprehensive Review of Neuroimaging in a Rare Inflammatory Entity

Xanthogranuloma of the sellar region is a rare chronic inflammatory lesion resulting from secondary hemorrhage, inflammation, infarction, and necrosis of an existing Rathke’s cleft cyst, craniopharyngioma, or pituitary adenoma. Sellar xanthogranulomas are challenging to differentiate from other cystic lesions preoperatively due to the lack of characteristic imaging features. We performed a literature overview of the clinical and paraclinical features, treatment options, and long-term outcomes of patients with sellar xanthogranuloma, focusing on the preoperative radiological diagnosis. The hyperintense signal in both T1- and T2-weighted sequences, cystic or partially cystic morphology, ovoid shape, sellar epicenter, intra- and suprasellar location, intratumoral calcifications, linear rim contrast enhancement, and the absence of cavernous sinus invasion suggest xanthogranuloma in the preoperative differential diagnosis. An endoscopic endonasal gross total resection without radiotherapy is the preferred first-line treatment. Given the low rate of recurrence rate and low chance of endocrinological recovery, a mass reduction with decompression of the optic apparatus may represent an appropriate surgical goal. Identifying the xanthogranulomas’ mutational profile could complement histopathological diagnosis and give insight into their histo-pathogenesis. A better preoperative neuroimagistic diagnosis of sellar xanthogranulomas and differentiation from lesions with a poorer prognosis, such as craniopharyngioma, would result in an optimal personalized surgical approach.

Sellar xanthogranuloma: A diagnostic challenge

Background:

Sellar xanthogranulomas are rare intracranial lesions comprising <1% of all sellar lesions. They were described as a separate entity by the World Health Organization in 2000. Because of the paucity of sellar xanthogranuloma cases reported in the literature, they remain a diagnostic challenge with indefinite origin, clinical course, and outcome. The present study reports a case of sellar xanthogranuloma describing the clinical presentation, radiological/pathological characteristics, and outcome.

Case Description:

A 43-year-old female, known to have diabetes, hypothyroidism, and polycystic ovarian syndrome, presented with a 2-week history of sudden right-sided facial deviation, periorbital pain, and moderate-intensity headache. The patient also reported amenorrhea not improving with polycystic ovarian syndrome treatment. Neurologic examination showed bilateral visual field defects and impaired visual acuity. Computed tomography scan, without contrast, revealed a hypodense sellar lesion with areas of hyperdensity. Magnetic resonance imaging showed a well-defined sellar lesion, exhibiting high signals on T1-weighted and T2-weighted images. The patient underwent microscopic trans-nasal trans-sphenoidal excision of the lesion. Histological sections of the sellar lesion revealed fibrous connective tissue with chronic inflammatory cells and cholesterol clefts, suggestive of xanthogranuloma. The patient is currently followed up at neurosurgery, endocrinology, and ophthalmology clinics with periodic laboratory/radiological investigations.

Conclusion:

Sellar xanthogranulomas remain rare intracranial lesions with few cases reported in the literature. Patients mostly present with severe hypopituitarism and visual dysfunction. They show no characteristic radiological features. The diagnosis is confirmed histopathologically, and the prognosis is generally favorable.

Xanthogranulomatous Pituitary Adenoma in a Dog with Typical Hyperadrenocorticism

Xanthogranuloma of the sellar region has been reported in both humans and animals. The lesion is rare, and its aetiology and pathogenesis are not fully understood. The association of sellar xanthogranuloma with an adenoma, known as xanthogranulomatous pituitary adenoma (XPA), is an extremely rare condition in humans and is usually associated with anterior pituitary insufficiencies, headache, vomiting and visual deficits. We present the first report of XPA in an animal. A 7-year-old male neutered Labrador Retriever was presented for investigation of progressive lethargy, vomiting and hyporexia, having been previously diagnosed with chronic kidney disease, pituitary-dependent hyperadrenocorticism and hypoparathyroidism. The dog was euthanized due to lack of response to medical treatment and post-mortem examination revealed XPA. Although rare, xanthogranulomatous lesions should be considered in patients with pituitary disease.

Xanthogranuloma of the sellar region: A case report

RATIONALE

Xanthogranuloma of the sellar region is exceedingly rare, and described in only a handful of case reports. Herein, we present a case of xanthogranuloma of the sellar region to improve our knowledge for the diagnosis and management of this unusual disease.

PATIENT CONCERNS

A 50-year-old female presented with the symptoms of intermittent vomiting, occasional head discomfort, and diabetes insipidus of 1 month duration.

DIAGNOSES

Magnetic resonance imaging showed a large well-defined, vase-like, heterogeneous mass in the sellar region. The lesion showed mixed signal with hierarchical signal presentation. Fluid-fluid level sign can be found within the lesion. The upper part of the lesion was hyperintense, and the lower part was hypointense on both T1-weighted images and T2-weighted images. The lesion showed no enhancement following the intravenous administration of gadolinium. The normal pituitary tissue was not clearly visible. Optic chiasm was compressed and displaced by the lesion. Initial diagnosis of pituitary macroadenoma with hemorrhage in the sellar region was made before surgery. Final diagnosis of sellar xanthogranuloma was confirmed by histopathological examination after surgical resection.

INTERVENTIONS

Gross total resection of the lesion was achieved using the microscope through endonasal transsphenoidal approach.

OUTCOMES

The patient recovered well with improved binocular vision and no symptom of diabetes insipidus, and was discharged 5 days after operation.

LESSONS

Sellar xanthogranuloma should receive diagnostic consideration for the lesion that is a heterogeneously mixed mass with a degree of T1-weighted images hyperintense in the sellar region.

Sellar Cholesterol Granuloma Mimicking Cystic Sellar Lesions: A Report of Three Cases and Literature Review

BACKGROUND

Cystic lesions in the sellar region include a variety of entities, such as craniopharyngioma, Rathke cleft cyst (RCC), intrasellar arachnoid cyst, cystic pituitary adenomas, cholesterol granulomas (CGs), and xanthogranulomas (XGs). The distinction among them remains a preoperative challenge due to similarities in their clinical and radiologic findings.

CASE DESCRIPTION

We describe 3 cases with cystic sellar lesions. The first patient is a woman who presented with headache and hormonal disturbances, including high levels of prolactin, with a sellar and suprasellar cystic lesion discovered on magnetic resonance imaging. She was initially treated with dopamine agonists with normalization of prolactin levels but no changes on the size of the lesion. She underwent an endoscopic endonasal resection and the histology resulted in a CG/XG. The second patient is a woman who consulted for an incidentally discovered sellar cyst. During the follow-up, the lesion demonstrated enlargement with compression of the optic chiasm. With a preoperative diagnosis of RCC, the lesion was removed through an endoscopic endonasal transsellar approach. Final pathologic diagnosis was consistent with CG/XG. The third case was that of a man who presented with refractory headaches and vision loss, with a sellar/suprasellar cystic lesion on magnetic resonance imaging. He underwent endoscopic endonasal transsellar surgery for resection of what preoperatively was thought to be a giant RCC; final pathology again was consistent with CG/XG.

CONCLUSIONS

CG/XG is an uncommon pathology with unspecific clinical and radiologic features. However, this pathology should be considered in the differential diagnosis of mixed cystic/solid lesions in the sellar region.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Functioning Pituitary Adenoma with Xanthogranulomatous Features: Review of Literature and Case Report

Objectives  We present a patient with a prolactin-secreting adenoma with extensive secondary, noninfectious, xanthogranulomatous changes due to remote intratumoral bleeding and provide a literature review of xanthogranulomas (XGs) of the sellar region with emphasis on prolactinomas with xanthogranulomatous features. Design  Case report, with PubMed search of cases of sellar XG, focusing on neuroimaging and surgical approach. Results  A 35-year-old male was found to have a large sellar/suprasellar calcified/cystic mass. Endoscopic transsphenoidal approach for extradural resection was performed and diagnosis made. Review generated 31 patients with the diagnosis of sellar XG. In a minority (6 patients), the underlying lesion for the XG was a pituitary adenoma. Headache was the most common presenting symptom and panhypopituitarism the most common endocrinological abnormality. Examples of hyperprolactinemia associated with sellar XG are also uncommon and due to stalk effect. Neuroimaging of XG on T1-weighted magnetic resonance imaging (MRIs) showed 18 cases (56.3%) were hyperintense, 1 case (3.13%) was isointense, 4 (12.5%) had mixed-signal intensity, and 2 (6.25%) were hypointense. On T2-weighted MRIs, five lesions (15.6%) were hyperintense, three (9.38%) were isointense, nine (28.1%) were heterogeneous, and nine (28.1%) were hypointense. Only one case (3.1%) had calcifications on computed tomography scan similar to ours. In 14 cases (43.7%), the lesions enhanced with contrast administration on MRI. Conclusion  Prolactinomas with secondary xanthogranulomatous change represent a rare cause of XG of the sella. With no radiological or clinical signs specific for XG of the sellar region, preoperative diagnosis can be challenging, if not impossible.

Giant Sellar Xanthogranuloma after Surgical Treatment of Symptomatic Rathke's Cleft Cyst

Extremely massive sellar xanthogranuloma (XG) are rare, and the surgical outcome and prognosis are not well known. XG remain unknown whether they are derived from Rathke's cleft cysts (RCCs) or craniopharyngiomas (CPs) following extensive inflammation and metaplasia, to the point that no epithelium is readily identifiable. These lesions usually tend to occur in younger patients (mean 28.3 years), have a smaller diameter, and remain primarily intrasellar region with infrequent calcification. This 36-year-old man presented our hospital with visual deterioration. At the time of visit, there were no neurological problems other than visual field defect and hormonal disorder. He visited our hospital in 2007 due to headache and decreased vision, and underwent transphenoid surgery for pituitary RCC. Since then, he has received treatment at our hospital for postoperative hormonal disorders. Through preoperative imaging study, the author suspected CP and underwent surgery. During the operation, the adhesion of the tumor to the surrounding major neurovascular structures was severe in the naked eyes, but the tumor could be removed more easily than expected. The postoperative histological findings were confirmed as XG. The postoperative course was uneventful. Compared to the previous literature, this case is a case where the size of XG is very large in a sellar region and it can be proved that it originated from the RCC. And regular follow-up is necessary to confirm the prognosis after surgery.

Pituitary xanthogranulomas: clinical features, radiological appearances and post-operative outcomes

BACKGROUND

Xanthogranulomas are inflammatory masses most commonly found at peripheral sites such as the skin. Sellar and parasellar xanthogranulomas are rare and present a diagnostic challenge as they are difficult to differentiate from other sellar lesions such as craniopharyngiomas and Rathke's cleft cysts pre-operatively. Their radiological imaging features are yet to be clearly defined, and clinical outcomes after surgery are also uncertain. This study reviews clinical presentation, radiological appearances, and clinical outcomes in a cohort of patients with pituitary xanthogranulomas.

METHODS

A prospectively maintained pituitary surgery database was screened for histologically confirmed pituitary xanthogranulomas between May 2011-December 2016. Retrospective case note assessments were then performed by three independent reviewers. Patient demographics, clinical presentations, imaging, and clinical outcomes were analysed.

RESULTS

During the study period 295 endoscopic endonasal pituitary surgeries were performed. Six patients had confirmed pituitary xanthogranulomas (2%). Patients most commonly presented with visual field deficits and/or endocrine dysfunction. Common imaging features included: a cystic consistency, hyperintensity on T1-weighted MR images, and contrast enhancement either peripherally (n = 3) or homogenously (n = 3). The most common pre-operative endocrine deficits were hyperprolactinaemia and hypoadrenalism (at least one of which was identified in 4/6 patients; 66%). Thirty-three percent (2/6) of patients presented with diabetes insipidus. The most common post-operative endocrinological deficits were adrenocortical dysfunction (66%) and gonadotropin deficiency (66%). Visual assessments normalised in all six patients post-operatively. Gross total resection was achieved in all patients, and at median follow up of 33.5 months there were no cases of tumour recurrence.

CONCLUSIONS

The prevalence of pituitary xanthogranulomas in our series is higher than that suggested in the literature. Surgery restored normal vision to all cases, however four patients (67%) required long-term hormonal replacement post-operatively. Imaging features such peripheral rim enhancement, a suprasellar tumour epicentre, and the absence of both calcification or cavernous sinus invasion were identified as potential indicators that together should alert clinicians to the possibility of pituitary xanthogranuloma when assessing patients with cystic sellar and parasellar tumours.

Pediatric Case of Xanthogranuloma in the Sellar Region Presenting a Visual Disturbance Successfully Treated with Endoscopic Endonasal Surgery

BACKGROUND

Xanthomatous pituitary diseases rarely occur in childhood. We report a rare pediatric case of a xanthogranuloma that developed in the sellar region, resulting in a visual disturbance that was treated successfully with endoscopic endonasal surgery.

CASE DESCRIPTION

A 13-year-old boy came to us with a headache and visual disturbance that occurred 1 month prior. Clinical examination findings showed that he was alert with signs of bitemporal hemianopsia. An endocrinologic examination showed partial hypopituitarism, and brain magnetic resonance imaging revealed a cystic mass in the sellar turcica compressing the optic apparatus. Endoscopic endonasal surgery was performed to decompress the optic apparatus, and the mass was removed. Histopathologic analysis of the tumor demonstrated granulomatous tissue with cholesterol clefts, foamy macrophages, and multinucleated giant cells, with no epithelial component. The diagnosis was xanthogranuloma of the sellar region. The patient gradually recovered from the visual disturbance and was free from any neurologic signs or symptoms 6 months after surgery.

CONCLUSIONS

Xanthogranuloma, although rare, should be considered as a differential diagnosis of a sellar or suprasellar lesion, even in children.

Cholesterol granulomas presenting as sellar masses: a similar, but clinically distinct entity from craniopharyngioma and Rathke's cleft cyst

PURPOSE

Cholesterol granulomas in the sella are rare and can mimic the appearance of craniopharyngioma or Rathke's cleft cysts. Information regarding the clinical presentation, imaging characteristics, and clinical course of sellar cholesterol granulomas can help clinicians to differentiate these lesions from other sellar cystic lesions.

METHODS

We present three cases of sellar cholesterol granulomas. A literature review was performed for all cases of sellar cholesterol granulomas with individual patient data reported.

RESULTS

We identified 24 previously reported cases in addition to our three cases. Mean age was 36.6 years (range 5-68). There were 16 (59%) females. The most common (74%) presenting symptom was endocrinological deficits, typically either isolated diabetes insipidus (DI) or panhypopituitarism. Location was intrasellar in 3 (11%), suprasellar in 6 (22%), and intrasellar/suprasellar in 18 (67%) patients. Lesions were most commonly (83%) T1 hyperintense. Gross total resection was achieved in 16 (64%) and subtotal resection in 9 (36%) patients. Of the seventeen (63%) patients presenting with varying degrees of bitemporal hemianopsia, all had improvement in vision postoperatively. It is worth noting that no cases of preoperative hypopituitarism or DI improved postoperatively. Even though gross total resection was only achieved in 64%, there was only one recurrence reported.

CONCLUSION

Sellar cholesterol granulomas are characterized by T1 hyperintensity, younger age, and more frequent and severe endocrinological deficits on presentation. Our review demonstrates high rates of improvement of visual deficits, but poor rates of endocrine function recovery. Recurrence is uncommon even in cases of subtotal resection.

Review of xanthomatous lesions of the sella

Xanthomatous lesions of the sellar region have traditionally been divided into two separate categories, xanthomatous hypophysitis (XH) and xanthogranuloma (XG) of the sellar region. The seminal article on XH, a condition typified by foamy histiocytes and lymphoplasmacytic infiltrates in the pituitary gland/sellar region, but usually little or no hemosiderin pigment, detailed three patients. However, most reports since that time have been single cases, making understanding of the entity difficult. In contrast, the seminal report on XG, characterized by sellar region cholesterol clefts, lymphoplasmacytic infiltrates, marked hemosiderin deposits, fibrosis, multinucleated giant cells around cholesterol clefts, eosinophilic granular necrotic debris, and accumulation of macrophages, included 37 patients, allowing more insights into etiology. Few examples could be linked to adamantinomatous craniopharyngioma, and although ciliated epithelium similar to that of Rathke cleft cyst (RCC) was identified up to 35% of the 37 cases, it could not be proven that XG was related to hemorrhage into RCC. Case reports since that time, however, occasionally linked XG to RCC when an etiology could be identified at all, and a few recognized that a spectrum exists in xanthomatous lesions of the sella. They review literature, adding 23 cases from our own experience, to confirm that overlap occurs between XH and XG, and that the majority-but not all-can be linked to RCC leakage/rupture/hemorrhage. It was suggested that progressive accumulation of hemosiderin pigment in the lesion, possibly caused by the multiple episodes of bleeding, could account for the transition of at least some cases of XH to XG.

Remarkable Diagnostic Magnetic Resonance Imaging Findings in Sellar Xanthogranuloma: Report of Three First Cases in Latin America

The sellar xanthogranuloma is a rare lesion of the sellar–parasellar region difficult to differentiate from other tumors such as craniopharyngiomas or Rathke's cleft cyst in the preoperative evaluation. As they are recently recognized as a separate entity and the few number of reports in the literature, its etiology is unknown and its impact remains uncertain. This article will describe the first three cases reported in Latin America, identified in one of them an imaging feature that may be helpful to elucidate an imaging growth pattern. Current evidence will be described regarding to the clinicopathological features, imaging diagnosis, and etiology origin theories.

Xanthogranuloma as an unsuspected cause of idiopathic central diabetes insipidus

OBJECTIVE

To demonstrate that xanthogranuloma is a rare cause of idiopathic central diabetes insipidus in the early phase of the disease and that it presents as a suprasellar mass at a later stage. In addition, we emphasize the importance of identifying the cause of idiopathic central diabetes insipidus and review the literature concerning endocrine disturbance in central xanthogranuloma.

METHODS

Review of recently published case reports of central xanthogranuloma with endocrine disorders. The case of a 35-year-old man who presented with a very large suprasellar mass is also reported. The patient was diagnosed with idiopathic central diabetes insipidus 20 years ago with normal brain magnetic resonance imaging.

RESULTS

Most cases of this disease present as supra- or parasellar masses with endocrine involvement, the most common of which (in approximately 75% of patients) is sex hormone deficiency. Diabetes insipidus was found in 65% of patients.

CONCLUSION

Xanthogranuloma should be in the differential diagnosis of idiopathic central diabetes insipidus and sellar and parasellar masses. A detailed skin examination is very important in making the diagnosis of central diabetes insipidus.

MRI and histopathologic study of a novel cholesterol-fed rabbit model of xanthogranuloma

PURPOSE

To develop a rabbit model of xanthogranuloma based on supplementation of dietary cholesterol. The aim of this study was to analyze the xanthogranulomatous lesions using magnetic resonance imaging (MRI) and histological examination.

MATERIALS AND METHODS

Rabbits were fed a low-level cholesterol (CH) diet (n = 10) or normal chow (n = 5) for 24 months. In vivo brain imaging was performed on a 3T MR system using fast imaging employing steady state acquisition, susceptibility-weighted imaging, spoiled gradient recalled, T1 -weighted inversion recovery imaging and T1 relaxometry, PD-weighted and T2 -weighted spin-echo imaging and T2 relaxometry, iterative decomposition of water and fat with echo asymmetry and least-squares estimation, ultrashort TE MRI (UTE-MRI), and T2* relaxometry. MR images were evaluated using a Likert scale for lesion presence and quantitative analysis of lesion size, ventricular volume, and T1 , T2 , and T2* values of lesions was performed. After imaging, brain specimens were examined using histological methods.

RESULTS

In vivo MRI revealed that 6 of 10 CH-fed rabbits developed lesions in the choroid plexus. Region-of-interest analysis showed that for CH-fed rabbits the mean lesion volume was 8.5 ± 2.6 mm(3) and the volume of the lateral ventricle was significantly increased compared to controls (P < 0.01). The lesions showed significantly shorter mean T2 values (35 ± 12 msec, P < 0.001), longer mean T1 values (1581 ± 146 msec, P < 0.05), and shorter T2* values (22 ± 13 msec, P < 0.001) compared to adjacent brain structures. The ultrashort T2* components were visible using UTE-MRI. Histopathologic evaluation of lesions demonstrated features of human xanthogranuloma.

CONCLUSION

Rabbits fed a low-level CH diet develop sizable intraventricular masses that have similar histopathological features as human xanthogranuloma. Multiparametric MRI techniques were able to provide information about the complex composition of these lesions. J. Magn. Reson. Imaging 2016;44:673-682.

Parasellar xanthogranulomas

OBJECT

Xanthogranulomas are rare inflammatory masses most often found in the skin and eye. The incidence of intracranial xanthogranulomas is 1.6%–7%, with those found in the sellar and parasellar region being exceedingly rare and their etiology controversial. Sellar and parasellar xanthogranulomas are rarely reported in the western hemisphere, and their incidence in Western countries is unknown.

METHODS

A prospectively acquired database of all endonasal endoscopic transsphenoidal surgeries performed at Weill Cornell Medical College was queried. Patients with histologically confirmed xanthogranulomas who were diagnosed and treated between 2003 and 2013 were included in the study. Patient history, demographic data, histological findings, and surgical approach were also evaluated.

RESULTS

A total of 643 endonasal endoscopic procedures had been performed at the time of this study. Four patients (0.6%) were identified as having a histologically confirmed xanthogranuloma of the parasellar region, compared with an incidence of 6.7% for craniopharyngioma (CP) and 2% for Rathke cleft cyst (RCC). The most common symptom was visual loss, followed by headache. Preoperative diagnosis was CP in all cases. All patients underwent extended endonasal endoscopic transsphenoidal surgery with gross-total resection. Two patients developed panhypopituitarism after surgery. There were no CSF leaks. The mean follow-up was 61 months, at which time there were no recurrences. The key histological features differentiating xanthogranulomas from CPs were accumulation of foamy macrophages, multinucleated foreign body giant cells, cholesterol clefts, and hemosiderin deposits without stratified squamous epithelium. These histological features appear commonly as part of the spectrum of a secondary inflammatory response in an RCC.

CONCLUSIONS

Parasellar xanthogranulomas most closely approximate CPs clinically but pathological evidence may suggest an RCC origin. Gross-total resection can be achieved through extended endonasal endoscopic transsphenoidal approaches, and is curative.