Xanthogranulomatous pituitary adenoma: A case report and literature review.

Xanthogranuloma, also referred to as cholesterol granuloma or xanthogranulomatous reaction, is a granulomatous lesion that is infrequently found in the sellar and parasellar regions. Xanthogranulomatous pituitary adenoma is relatively rare and, thus, the etiology, diagnosis, management and prognosis of this condition remain incompletely understood. We herein report the case of a 56-year-old female patient who presented to our institution with intermittent headache, vomiting and distending pain in the bilateral orbital regions. Brain magnetic resonance imaging revealed a sellar mass with a heterogeneous signal. The mass was subtotally resected, and histopathological examination confirmed the diagnosis of xanthogranulomatous pituitary adenoma. Although the patient's symptoms were relieved following surgical treatment, intractable hyponatremia and diabetes insipidus developed and she received hormone replacement therapy. At the last follow-up (November 2016), the patient remained recurrence-free. A total of 14 cases of pituitary adenoma with concomitant xanthogranuloma were identified in the literature, and the clinical and radiological manifestations are discussed. Sellar xanthogranuloma is usually associated with craniopharyngioma or Rathke's cleft cyst; however, it may also occur in isolation. Xanthogranulomatous pituitary adenomas are infrequent, making their diagnosis challenging. Surgical resection is the preferred treatment, and attention should be paid to postoperative hypopituitarism and development of diabetes insipidus.