Xanthogranuloma of Sellar Region : A Case Report with Diagnostic Imaging Findings , Treatment Response and Literature Review

Xanthogranuloma of sellar region is uncommon and difficult to differentiate from craniopharyngioma, Rathke’s deft cyst and other sellar lesions by imaging findings. In this article, we report a rare case of sellar xanthogranuloma in a 49-year-old woman who presented with headache and visual defect. Computed tomography (CT), magnetic resonance imaging (MRI), and partial surgical excision were performed and pathology confirmed the diagnosis. Postoperative follow-up series of imaging studies demonstrated the residual tumor evolution in various size and partial response to the radiotherapy. Current evidence regarding to the clinicopathologic and radiological features of sellar xanthogranuloma will be summarized, along with discussion on its main differential diagnoses. Correspondence Author to: Yu-Kun Tsai Department of Medical Imaging, Chi Mei Medical Center, Yong-Kang, Tainan, Taiwan No.901, Zhong-Hua Road, Yong-Kang, Tainan 710, Taiwan J Radiol Sci 2012; 37: 89-94 Xanthogranuloma of sellar region 90 J Radiol Sci June 2012 Vol.37 No.2 with suprasellar extension and tight compression of the right optic nerve and optic chiasm. The tumor was cystic with cholesterol and bile-like fluid. Microscopic study of the surgical specimen showed that the tumor was composed of macrophages, giant cells with lymphocytic infiltration, dystrophic calcification, cholesterol cleft formation and hemosiderin deposition (Fig. 2). There were tiny sloughed squamous epithelia identified. The histological diagnosis of sellar xanthogranuloma was rendered. The postoperative course was uneventful except for the presence of transient diabetes insipidus. Postoperatively there were minimal recovery of the visual acuity (OD from blindness to 0.1) and mild improvement of bitemporal hemianopia. However, the hypopituitarism was still noted. Post-operative MRI was arranged 6 months later and demonstrated a residual sellar tumor measuring about 3.5 × 2.5 × 4 cm. The sequential annual MRI for the next three years showed tumor evolution with various diameters from 2.8 to 3.5cm. The follow-up MRI about 20 months after surgery revealed the prominent dark signal intensity with "blooming" effect on the gradient echo sequence and susceptibility-weighted images (SWI) (Fig. 3a, 3b). He was then referred for post-operative radiotherapy which consisted of a total radiation dose of 2500 cGy in 5 fractions. The tumor showed marked shrinkage of the size (2.2 cm) about one year later.