Lymphoplasmacytic hypophysitis associated with immunoglobulin G4

Area of Science:

• Endocrinology
• Neuroimaging
• Immunopathology

Background:

• Sellar lesions can present with varied etiologies, including pituitary adenomas and inflammatory conditions.
• Amenorrhea and sellar mass are common presenting symptoms requiring thorough differential diagnosis.

Observation:

• A 33-year-old woman presented with a 2-year history of amenorrhea and an expanding sellar lesion.
• Magnetic resonance imaging (MRI) revealed a pituitary fossa lesion initially suspected to be a pituitary adenoma.
• The lesion enlarged by 5mm over one year, with dural and pituitary stalk enhancement.

Findings:

• Histopathology demonstrated a lymphocytic and plasma cell inflammatory infiltrate.
• The findings were suggestive of lymphoplasmacytic hypophysitis.
• The condition was associated with immunoglobulin G4 (IgG4) deposition.

Implications:

• This case highlights IgG4-related hypophysitis as a rare differential diagnosis for sellar masses.
• Accurate diagnosis is crucial for appropriate management and to differentiate from neoplastic lesions.
• Understanding IgG4-related hypophysitis expands the spectrum of sellar pathology.