Primary hypophysitis: Classification review.

Area of Science:

• Endocrinology
• Pathology
• Immunology

Background:

• Primary hypophysitis is classified into lymphocytic, granulomatous, necrotizing, or IgG4-related disease.
• Secondary hypophysitis is linked to systemic conditions, often negating biopsy needs.
• Primary hypophysitis can mimic pituitary tumors, necessitating histological confirmation.

Purpose of the Study:

• To detail primary hypophysitis cases and discuss challenges in histological classification.
• To explore the role of IgG4+ cells in different hypophysitis subtypes.
• To evaluate treatment outcomes irrespective of precise histological diagnosis.

Main Methods:

• Case series of four women with primary hypophysitis.
• Histopathological analysis of pituitary biopsies, including IgG4 staining.
• Review of clinical presentations, suspected diagnoses, and treatment responses.

Main Results:

• Four women (32-76 years) presented with symptoms like weakness and visual changes, suspected of having pituitary macroadenoma.
• Biopsies showed lymphocytic hypophysitis (with/without IgG4+ cells) and granulomatous hypophysitis (with necrosis, IgG4+ cells, giant cells).
• Steroid therapy, with rituximab in one case, was administered, showing efficacy across different histological types.

Conclusions:

• Histological classification of primary hypophysitis can be challenging, with overlap in features like IgG4+ cells.
• Granulomatous and necrotizing types are less common and can feature numerous IgG4+ cells.
• Treatment with steroids, and potentially rituximab, may be effective for all hypophysitis types, possibly reducing reliance on exact histological distinctions.