Xanthomatous Hypophysitis Is Associated with Ruptured Rathke's Cleft Cyst

Area of Science:

• Endocrinology
• Pathology
• Neurosurgery

Background:

• Xanthomatous hypophysitis is a rare pituitary inflammation.
• Its pathogenesis is poorly understood, but may involve secondary reactions to ruptured cysts.
• It can mimic pituitary neoplasms clinically and radiologically.

Purpose of the Study:

• To investigate the association between xanthomatous hypophysitis and Rathke's cleft cysts.
• To characterize the clinical and pathological features of xanthomatous hypophysitis.
• To classify xanthomatous hypophysitis based on its pathogenesis.

Main Methods:

• Retrospective review of 1221 pituitary specimens.
• Identification of seven cases of xanthomatous hypophysitis.
• Preoperative radiological and biochemical workup, endoscopic transsphenoidal resection, and pathological examination.

Main Results:

• Seven cases of xanthomatous hypophysitis were identified.
• All cases showed foamy macrophages, giant cells, and chronic inflammation.
• Six patients presented with cystic pituitary masses (mean 2.0 cm) and five had endocrine dysfunction.
• Concurrent ruptured Rathke's cleft cyst was found in all but one patient with prior surgery.

Conclusions:

• Xanthomatous hypophysitis predominantly occurs secondary to ruptured Rathke's cleft cysts.
• It should be considered in the differential diagnosis of cystic pituitary lesions.
• It is best classified as a secondary (reactive) hypophysitis.