Recurring Primary Xanthomatous Hypophysitis Behaving Like Pituitary Adenoma: Additional Case and Literature Review

Xanthomatous hypophysitis (XH) is the rarest histologic type of primary hypophysitis. It is nonlymphocytic and characterized by an infiltration of the pituitary gland by lipid-laden histiocytes and macrophages. The clinical and radiologic features overlap heavily with pituitary adenomas and are prone to misdiagnosis. We describe a rare case of XH recurrence at 1 year, treated surgically. Moreover, we provide an updated review of the literature to further elucidate useful management and detection strategies.

A 45-year-old woman presented with a history of menstrual irregularity for 9 months, amenorrhea, galactorrhea, and headache for 2 months duration. Preoperative endocrinologic studies showed increased prolactin levels. Magnetic resonance imaging of the sella showed a cystic lesion with suprasellar extension suggestive of a pituitary adenoma. The patient underwent transsphenoidal resection, showing a thick yellowish colloidal material. Histopathology showed necrotic tissue with no definitive diagnosis and no identified microorganisms. At 2 months after surgery, prolactin levels and menstrual cycle normalized. At 1 year after surgery, her menstrual cycle again became irregular. Repeat magnetic resonance imaging showed a recurrent mass and a second transsphenoidal resection was undertaken. Repeat histopathology was consistent with XH. The patient is 9 years postoperative and is doing well without evidence of recurrence.

XH presents similarly to nonfunctional adenomas and diagnosis remains difficult without surgical pathology, requiring meticulous immunohistochemistry to prevent misdiagnosis. Thus, XH should be considered as a rare cause in the differential of disease of the sellar region. Management can parallel that of pituitary neoplasm, with a focus on radiosurgery, re-resection, and high-dose steroids.