the world health organization ( who ) appointed xanthogranuloma of the sellar region as a specific type of brain tumor in 2000 , differentiating it from adamantinomatous craniopharyngioma ( cp ) . they are a rare entity , with two cases reported in the western hemisphere.1 
 2 histologically , xanthogranulomas correspond to a granulomatous reaction characterized by the presence of cholesterol crystals , foamy macrophages , giant cells , hemosiderin deposits , necrotic detritus , lymphocytic infiltrate , and fibrous proliferation.3 since the 37 cases were reported by paulus et al,3 21 reports have been documented since 2000 , without previous reports in latin america.2 
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  the etiology of xanthogranulomas of the sellar region is controversial , and there are currently two hypotheses under greater discussion . the first states that xanthogranulomas originate from an inflammatory reaction , hemorrhage or rupture of a rathke 's cleft cyst ( rcc ) . the second hypothesis postulates that xanthogranulomas arise from a secondary inflammatory progression of a cp.19 
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 24 until now , there is no preoperative diagnostic method , imaging and immunohistochemical studies have not been sufficient by themselves to achieve accurate preoperative diagnosis.1 
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 21 we report three cases of sellar xanthogranuloma , highlighting an imaging finding in one of the cases that might be helpful to elucidate a characteristic pattern of these lesions . a 10-year - old patient , obese , with no other relevant medical history , presented with a 1-year history of recurrent episodes of headache associated with blurred vision , polyuria , and polydipsia . magnetic resonance imaging ( mri ) of the brain showed a cystic solid heterogeneous sellar mass with suprasellar extension , suggestive of cp or pituitary adenoma ( figs . 1 and 2 ) . ( a ) sagittal t1 precontrast and ( b ) sagittal t1 postcontrast . sellar macroscopically , the mass was described as similar to a cp with an old hematoma at its center . histological examination revealed findings consistent with xanthogranuloma . at 38 months ' follow - up after surgery , the patient had a significant improvement in visual disturbances , with no more headache episodes , polyuria , and polydipsia . a 35-year - old male patient , with a history of dyslipidemia , presented a 2-year history of recurrent headache , progressive visual loss , blurred vision , decreased libido and erectile dysfunction . the visual field test showed a superior temporal quadrantanopsia in the left eye and a temporal hemianopsia in the right eye . the mri showed an expansive process of the sellar  suprasellar region , partially cystic , slightly heterogeneous , hyperintense on t1-weighted and heterogeneous in t2-weighted image with calcifications , mass effect on the optic chiasm , and a retroclival dural tail with contrast enhancement ( fig . ( a ) sagittal t2 , ( b ) sagittal t1 precontrast , and ( c ) sagittal t1 postcontrast . suprasellar solid cystic expansion process with predominance of cystic component hyperintense in t2 , and a hypointense peripheric solid component ( a ) . cystic hyperintense in t1 ( b ) . solid peripheric component and retroclival dural tail slightly enhanced ( c ) . an extended endoscopic transsphenoidal , transselar , transtuberculum , transplanum approach was made without complications . histopathological examination showed the presence of cholesterol crystals , sclerosis and fibrosis of the connective tissue , cholesterol granulomas , lymphocytic infiltrate , hemosiderin deposits , and multinucleated giant cells without epithelial component , findings consistent with a xanthogranuloma ( fig . no complications developed in the postoperative period , except transient diabetes insipidus . at 8 months ' follow - up after surgery , the patient had no more headache episodes ; however , hypogonadism and visual field remain unimproved . postoperative mri showed a heterogeneous residual tumor appearance with a remnant of the retroclival dural tail before mentioned ( fig . ( a ) hematoxylin  eosin technique , fibrous tissue is observed with xanthogranulomatous chronic inflammation . postoperative ( a ) sagittal t1 precontrast , ( b ) sagittal t2 , and ( c ) sagittal t1 postcontrast . the anterior thin solid peripheral component shows slightly enhancement postcontrast and remaining retroclival dural tail . a 31-year - old male patient , without morbid or surgical history , presented with a 2-year history of progressive decrease libido and erectile dysfunction associated with loss of muscle mass and progressive visual loss in the right eye . endocrinological evaluation showed panhypopituitarism and brain mri showed a sellar mass contacting the optic chiasm ( fig . intra- and suprasellar cystic tumor with small solid excentric extension , with predominance of t1 hyperintense cystic component , and a thin peripheral solid component which slightly enhanced postcontrast . histopathological findings were consistent with xanthogranuloma like the other cases . at 6 months ' postoperative follow - up , parasellar region were considered as a variation of adamantinomatous cp.25 paulus et al3 proposed this pathological pattern as a distinct clinicopathological entity and compared these lesions with cps . they found several statistically significant differences highlighting the presentation at a younger age , intrasellar location , more severe endocrinological dysfunction , longer preoperative history , lower frequency of visual disturbances , and better surgical resectability with more favorable outcomes . therefore , this entity was added to the who brain tumor classification in 2000 , found mentioned in the third and fourth edition of the who classification of tumors of the central nervous system.26 
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  most cases of xanthogranulomas of the sellar region have been reported in asia with few reports in western hemisphere and none in latin america . there is controversy regarding the origin of these rare lesions , and there are two main hypotheses under greater discussion . the first theory postulates that xanthogranulomas originate from an inflammatory reaction , hemorrhage , or rupture of a rcc . the second theory proposes their origin from a secondary inflammatory progression of a cp.3 
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 24 however , there is also reports related to systemic diseases such as sarcoidosis7 and erdheim chester 's disease.5 
 16 the actual evidence is not yet conclusive regarding its etiology . the presence of squamous epithelium and calcifications reinforce the theory that relate xanthogranulomas to adamantinomatous cps,3 but the evidence gathered last year has been accumulating , favoring their origin related to rcc.1 
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  clinically , they are characterized by the presence of cephalea , weight loss , anorexia , nausea , fatigue , visual disturbances , and endocrine disorders ranging from mild deficiencies of one or more hormone to panhypopituitarism . they have also been reported as a cause of diabetes insipidus of central origin ( 510.19 ) and obstructive hydrocephalus.15 all our cases were nonfunctioning tumors . in our series of cases , headache was the predominant symptom in one case , while in the other two cases were secondary to hypogonadism . due to the rarity of this entity and considering its definitive diagnosis is by biopsy of the surgical specimen , the natural history of presentation of xanthogranuloma remains unknown , and there is no diagnostic method developed to achieve an accurate preoperative diagnosis to date . there are no typical radiological characteristics or patterns for xanthogranuloma.9 
 20 they have variable levels of intensity secondary to unpredictable bleeding patterns and calcified lesions associated ; therefore , it has not been possible to describe a typical imaging pattern presented consistently . we have conducted a literature review of previously reported cases of xanthogranulomas of the sellar  suprasellar region and elaborated a table focusing on the imaging characteristics with the intention of achieving an imaging pattern that contributes to the preoperative diagnosis ( table 1 ) , without finding patterns or consistency in its mr signal characteristics . recently , madan mohan et al23 reported a case with residual tumor followed up with mr assessment revealing the development of new lesions that may illustrate a growth pattern , one of these lesions described was the development of a dural tail , also developed in our case 2 , supporting it as an interesting feature that may elucidate a new imaging pattern that could be helpful in preoperative diagnosis . f , female ; hrt , hormone replacement therapy ; m , male ; mri , magnetic resonance imaging ; na , not available ; postop . the increased risk of pituitary dysfunction compared with cp and rcc is probably due to bleeding , inflammation , or degeneration of a primary lesion . regardless of tumor size , it appears that there is a better outcome when there is less intrasellar commitment and time between the onset of symptoms and the surgical resolution.19 surgical resection is the treatment of choice . the management has been almost universally treated by craniotomy or transsphenoidal microscopic surgery.17 
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 20 our three cases were treated by endoscopic endonasal transsphenoidal approach achieving a satisfactory exposure with no morbidity related to the surgical procedure , being less invasive than craniotomy . recurrences after complete resection are rare.16 radiotherapy has also been described as an effective treatment in a case of partial resection.20 otolaryngologists and neurosurgeons must be cognizant of the existence of sellar xanthogranulomas as a differential diagnosis . we report the first three cases in latin america , all of them operated by an endonasal endoscopic extended approach which allows a satisfactory exposure and gross tumor resection being a less invasive and effective approach to cure this pathology . the existence of a retroclival dural tail sign in a context of a sellar solid cystic lesions suspicious for a cp or rcc might be a specific feature that could raise the suspicion of a xanthogranuloma . further studies with mri assessment are needed to prove the reliability of this imaging characteristic .
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 .