Sellar xanthogranuloma: A diagnostic challenge

Abstract

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.

Keywords: Adenohypophysis; Cholesterol; Fibrous; Foamy; Granuloma; Pituitary.

Figure 1:

(a and b) Sagittal and coronal brain CT without contrast showing a hypodense lesion with areas of hyperdensities (Arrow). (c and d) Sagittal and coronal T1-weighed images with contrast of the pituitary gland. (e) Sagittal T2-weighted image. (c-e) The images demonstrate a well-defined, rounded sellar mass which exhibit a high signal on T1- and T2-weighted images (Arrow). The lesion causes deviation of the pituitary stalk to the left side and abuts the optic chiasm. It measures 19 × 20 × 12 mm in anteroposterior, transverse, and craniocaudal diameters.

Figure 2:

(a) Cholesterol clefts (H&E, original magnification ×100). (b) Foreign body giant cells between the cholesterol clefts (H&E, original magnification ×200). (c) Hemosiderin deposits (H&E, original magnification ×200). (d) Pituitary adenohypophysis (H&E, original magnification ×200).

Figure 3:

(a and b) Postoperative sagittal and coronal brain CT without contrast demonstrating expected postoperative changes in the form of opacification of the sinonasal cavity as well as fragmented pockets of air foci, along the hemorrhagic densities, within the surgical cavity (Arrow).