Pituitary Adenoma with Cholesterol Clefts

Area of Science:

• Endocrinology
• Neurosurgery
• Pathology

Background:

• Cholesterol clefts are common in craniopharyngioma, Rathke's cleft cyst, and granulomas.
• Their presence in pituitary adenomas is infrequent.
• Pituitary adenomas can cause hormonal imbalances and mass effects.

Purpose of the Study:

• To report a rare case of pituitary adenoma with cholesterol clefts.
• To investigate the histopathological and imaging features of such a tumor.
• To elucidate the potential pathogenesis of the cystic component.

Main Methods:

• Case presentation of a 46-year-old woman with visual field disturbance and galactorrhea.
• Magnetic resonance imaging (MRI) for tumor characterization.
• Trans-sphenoidal surgery for tumor resection.
• Histopathological examination including H&E staining, immunostaining, and electron microscopy.

Main Results:

• MRI revealed a pituitary tumor with an intratumoral cyst showing high signal intensity on T1- and T2-weighted images.
• Histopathology confirmed a chromophobic pituitary adenoma with ACTH immunoreactivity.
• Numerous cholesterol clefts and hemosiderin-laden macrophages were observed within the tumor and cyst.
• Electron microscopy showed sparse secretory granules and abundant lysosomes.

Conclusions:

• This case demonstrates a rare pituitary adenoma exhibiting cholesterol clefts.
• The cystic component is likely attributed to focal hemorrhagic infarction and subsequent degenerative changes.
• The findings underscore the importance of thorough histopathological evaluation for diagnosing rare pituitary lesions.