Table of Contents  
CASE REPORT
Year : 2014  |  Volume : 7  |  Issue : 5  |  Page : 651-654  

Dynamics of the dynamic enhancement in a suprasellar lesion: Diagnostic dilemmas and literature review


1 Department of Neurosurgery, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad, Andhra Pradesh, India
2 Department of Pathology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad, Andhra Pradesh, India

Date of Web Publication10-Sep-2014

Correspondence Address:
Ashish Kumar
Department of Neurosurgery, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad - 500 082, Andhra Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0975-2870.140485

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  Abstract 

Brain tumors with high vascularity show dynamic enhancement on magnetic resonance contrast imaging owing to their rapid blood flow. This principle is used to differentiate highly vascular lesions in sellar/suprasellar area from the non-vascular or mildly vascular ones. We report a case of suprasellar lesion affecting a 35-year-old female, lesion exhibiting dynamic enhancement on contrast magnetic resonance imaging. The imaging and intra-operative findings have created a diagnostic dilemma about the nature of the lesion and the histopathology revealed it to be a Rathke's cleft cysts (R.C.C). R.C.C have varied imaging manifestations. They can create diagnostic dilemma in a surgeon's mind when they present with such extremes of variations including dynamic contrast enhancement. One should be aware of these atypical imaging findings before approaching these lesions at surgery for an optimal outcome.

Keywords: Dynamic enhancement, Rathke′s cleft cyst, solid Rathke′s cleft cysts, suprasellar lesion


How to cite this article:
Narayana S, Kumar A, Barada SP, Uppin S. Dynamics of the dynamic enhancement in a suprasellar lesion: Diagnostic dilemmas and literature review. Med J DY Patil Univ 2014;7:651-4

How to cite this URL:
Narayana S, Kumar A, Barada SP, Uppin S. Dynamics of the dynamic enhancement in a suprasellar lesion: Diagnostic dilemmas and literature review. Med J DY Patil Univ [serial online] 2014 [cited 2020 Jul 12];7:651-4. Available from: http://www.mjdrdypu.org/text.asp?2014/7/5/651/140485


  Introduction Top


Diagnosing the exact pathology of a suprasellar lesion based on imaging is usually straight forward and we should be able to clinch the diagnosis easily most of the times. Magnetic resonance imaging (MRI) with gadolinium usually remains the investigation of choice. Pituitary adenomas, meningiomas, Rathke's cleft cysts (R.C.C), craniopharyngiomas, opticochiasmatic/hypothalamic gliomas and aneurysms constitute the majority of pathologies. Dynamic contrast study exhibits the temporal relation of the enhancement intensity and is helpful in differentiating a meningioma, hemangioma, or a cavernous malformation from other lesions of this region. [16] However, at certain times atypical imaging characteristics including contrast enhancement may create doubts in a neurosurgeon's mind and hence, keeping these in mind pre-operatively always helps achieve an optimal outcome surgically.


  Case Report Top


The present case is about a 55-year-old female presented with bifrontal, continuous, dull aching type of headache for the past 6 months. On neurological examination, there were no focal deficits. Visual fields and acuity were within normal limits. Computed tomography (CT) brain plain revealed a solitary, well defined, oval, extra axial lesion purely in the suprasellar region which was uniformly hyperdense. There was no sellar extension of the lesion [Figure 1]. MRI showed the lesion to be iso-intense on T1-W images and hypo-intense on T2-W images [Figure 2]. However, administration of contrast resulted in surprising findings. The axial images that were acquired initially showed homogenous intense enhancement of the lesion, whereas the sagittal and coronal sections that were acquired 3 min and 6 min after the axial images respectively, showed minimal enhancement [Figure 3], suggesting dynamic enhancement. This created doubts in the pre-operative diagnosis. Since pituitary was seen separately from the lesion, pituitary adenoma was ruled out. To rule out pathology arising from pituitary stalk owing to its doubtful attachment on imaging, a hormonal analysis was done which was within normal limits. In view of the lesion's location and intensity patterns, a thrombosed aneurysm was also suspected, but the angiogram was negative. Other differentials included were a meningioma pertaining to the intensity patterns, a craniopharyngioma and an opticochiasmatic glioma in view of doubtful attachment of the lesion to the chiasm [Figure 4]. With these various diagnostic possibilities in mind, patient was taken up for surgery (pterional craniotomy and trans-sylvian approach) as per patient's choice (versus observation). Intra-operatively, a yellowish, solid, completely avascular lesion without any attachment to pituitary stalk or chiasm was observed with a clear plane all around [Figure 5]. Gross total resection was performed. Histopathological examination showed the lesion to be lined by pseudo-stratified ciliated columnar epithelium with underlying hyalinized collagenous tissue, filled with amorphous eosinophilic secretions suggestive of R.C.C Post-operatively, patient improved symptomatically and post-operative CT showed no evidence of any residual lesion.
Figure 1: Computed tomography brain showing completely hyperdense lesion in the suprasellar region

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Figure 2: T1- and T2-weighted images showing iso- and hypo-intense lesions respectively in the suprasellar region seen separately from the pituitary stalk

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Figure 3: Contrast enhanced magnetic resonance imaging showing intense enhancement in the axial planes while the gadolinium is completely washed out in coronal and sagittal images which were acquired later

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Figure 4: The histopathology sections showing the cyst wall lined by columnar epithelium with collagen at the base H and E, ×100

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Figure 5: Intra-operative picture showing a completely solid, waxy and yellowish lesion completely separated from the optic chiasm

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  Discussion Top


R.C.C is non-neoplastic epithelial lined cyst occupying the sellar/suprasellar regions. There are many hypothesis regarding the development of R.C.C, [1],[2],[3] but the most widely accepted theory is that they originate from embryonic remnants of Rathke's pouch. [1] Even though the R.C.C's are common in occurrence, they do not come to medical attention since most of them are asymptomatic. 13-33% of pituitary sections at autopsy reveal R.C.C [4] If they become symptomatic, they usually manifest between 40 and 60 years of age, with female preponderance. Headache is the most common symptom, [5] followed by visual and endocrine disturbances. [6] Nishioka et al. [5] concluded that headache which is particularly bifrontal, non-pulsatile and episodic is a common and characteristic manifestation of R.C.C Commonly, R.C.C's are found in the sella between the pars anterior and posterior owing to its embryological origin from Rathke's pouch. [7] Suprasellar extension is also common, whereas purely suprasellar R.C.C are rare. [8],[9] The pars tuberalis lying above the diaphragma sella is the site of origin of entirely suprasellar R.C.C's. [10] Symptomatic, entirely suprasellar R.C.C with normal sella are very rare. [11] Wen et al. have studied 22 cases of R.C.C and in them 9 were intrasellar, 12 were intrasellar with suprasellar extension and only 1 case was of purely suprasellar variety. [8] Imageologically, on plain CT scans, R.C.C's are usually hypo- or iso-dense and rarely hyperdense as visualized in our patient. Furthermore, sometimes small intracystic nodules with low signal on T2-W and high signal on T1-W, which do not enhance are seen and are pathognomonic of R.C.C [12] Choi et al., [13] stated that lack of enhancement or thin cyst wall enhancement is the main differentiating feature of R.C.C from other neoplastic cysts of this region. The imaging characteristics may vary as per the cyst content (protein rich or not), but enhancement with contrast is usually lacking or of peripheral rim type. On the contrary, Wen et al., have actually described the role of dynamic MRI in differentiating pituitary adenomas from intrasellar R.C.C [8] But as observed in our case, R.C.C also showed a homogenous enhancement immediately after injection of gadolinium and the contrast washed out in minutes while the images were still being acquired. This type of dynamic intense enhancement of R.C.C is not described in the literature until now. Furthermore, the consistency of R.C.C is usually cystic, having occasionally few intracystic solid nodules. [7],[14] Ours was totally solid and waxy in composition. Solid R.C.C's are extremely rare and to the best of our knowledge they were published only by Tominaga et al. [15] They studied 31 cases of R.C.C's in which only four were totally solid, but none of them were suprasellar. From their study, they inferred that R.C.C's are usually oval or dumb-bell shaped with smooth walls and without evidence of any invasion in to the surrounding structures. They usually reach to a size of 1-4.5 cm by the time of diagnosis. Tissues adjacent to the R.C.C may also show contrast enhancement, which may be secondary to the gadolinium uptake by the normal but compressed pituitary gland or an inflamed cystic wall. CT scan can be of some help in differentiating R.C.C from craniopharyngioma with rate of calcifications in these two lesions being 13% and 87%, respectively. [15] The diagnosis of R.C.C was never thought of pre-operatively owing to these imaging characteristics. Moreover, as no attachment to the stalk could be identified, doubts about the theory of origin of suprasellar R.C.C from pars tuberalis may still exist. [10]


  Conclusion Top


R.C.C's are typically variable in their imaging findings, consistency and clinical presentation. They can create diagnostic dilemma in a surgeon's mind when they present with such extremes of variations including dynamic contrast enhancement. One should be aware of these atypical imaging findings before approaching these lesions at surgery for an optimal outcome. Furthermore, extensive work-ups for a similar lesion may be avoided in the future although we will require few more similar solid, entirely suprasellar and dynamically enhancing R.C.Cs to substantiate their entity.

 
  References Top

1.Fager CA, Carter H. Intrasellar epithelial cysts. J Neurosurg 1966;24:77-81.  Back to cited text no. 1
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2.Shuangshoti S, Netsky MG, Nashold BS Jr. Epithelial cysts related to sella turcica. Proposed origin from neuroepithelium. Arch Pathol 1970;90:444-50.  Back to cited text no. 2
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3.Asa SL. Tumors of the pituitary gland. In: Rosai J editor. Atlas of Tumor Pathology. 3 rd Series. Fascicle 22. Washington, DC: Armed Forces Institute of Pathology; 1998.  Back to cited text no. 3
    
4.Teramoto A, Hirakawa K, Sanno N, Osamura Y. Incidental pituitary lesions in 1,000 unselected autopsy specimens. Radiology 1994;193:161-4.  Back to cited text no. 4
    
5.Nishioka H, Haraoka J, Izawa H, Ikeda Y. Headaches associated with Rathke′s cleft cyst. Headache 2006;46:1580-6.  Back to cited text no. 5
    
6.Billeci D, Marton E, Tripodi M, Orvieto E, Longatti P. Symptomatic Rathke′s cleft cysts: A radiological, surgical and pathological review. Pituitary 2004;7:131-7.  Back to cited text no. 6
    
7.Bonneville F, Cattin F, Marsot-Dupuch K, Dormont D, Bonneville JF, Chiras J. T1 signal hyperintensity in the sellar region: Spectrum of findings. Radiographics 2006;26:93-113.  Back to cited text no. 7
    
8.Wen L, Hu LB, Feng XY, Desai G, Zou LG, Wang WX, et al. Rathke′s cleft cyst: Clinicopathological and MRI findings in 22 patients. Clin Radiol 2010;65:47-55.  Back to cited text no. 8
    
9.Wenger M, Simko M, Markwalder R, Taub E. An entirely suprasellar Rathke′s cleft cyst: Case report and review of the literature. J Clin Neurosci 2001;8:564-7.  Back to cited text no. 9
    
10.Barrow DL, Spector RH, Takei Y, Tindall GT. Symptomatic Rathke′s cleft cysts located entirely in the suprasellar region: Review of diagnosis, management, and pathogenesis. Neurosurgery 1985;16:766-72.  Back to cited text no. 10
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11.Itoh J, Usui K. An entirely suprasellar symptomatic Rathke′s cleft cyst: Case report. Neurosurgery 1992;30:581-4.  Back to cited text no. 11
    
12.Trifanescu R, Ansorge O, Wass JA, Grossman AB, Karavitaki N. Rathke′s cleft cysts. Clin Endocrinol (Oxf) 2012;76:151-60.  Back to cited text no. 12
    
13.Choi SH, Kwon BJ, Na DG, Kim JH, Han MH, Chang KH. Pituitary adenoma, craniopharyngioma, and Rathke cleft cyst involving both intrasellar and suprasellar regions: Differentiation using MRI. Clin Radiol 2007;62:453-62.  Back to cited text no. 13
    
14.Byun WM, Kim OL, Kim D. MR imaging findings of Rathke′s cleft cysts: Significance of intracystic nodules. AJNR Am J Neuroradiol 2000;21:485-8.  Back to cited text no. 14
    
15.Tominaga JY, Higano S, Takahashi S. Characteristics of Rathke′s cleft cyst in MR imaging. Magn Reson Med Sci 2003;2:1-8.  Back to cited text no. 15
    
16.Symons SP, Aviv RI, Montanera WJ, Kucharczk W. The sella turcica and parasellar region. In: Atlas SW, editor. Magnetic Resonance Imaging of the Brain and Spine. 4 th ed. Philadelphia: lippincott Williams & Wilkins; 2009. p. 1120-92.  Back to cited text no. 16
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]



 

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