Pituitary tuberculosis mimicking idiopathic granulomatous hypophysitis

Area of Science:

• Neurology
• Endocrinology
• Infectious Diseases

Background:

• Granulomatous hypophysitis is a rare inflammatory condition affecting the pituitary gland.
• Pituitary adenomas are common sellar masses, often diagnosed via MRI.
• Tuberculosis can present with diverse clinical and radiological manifestations.

Observation:

• A patient presented with a sellar mass initially diagnosed as pituitary adenoma.
• Histology revealed non-caseating granulomas, glandular destruction, and fibrosis, leading to a misdiagnosis of Idiopathic Granulomatous Hypophysitis.
• Acid-fast bacilli stains were negative, complicating the initial diagnosis.

Findings:

• The patient developed meningitis post-surgery, with cerebrospinal fluid (CSF) positive for Mycobacterium tuberculosis by PCR.
• This confirmed a diagnosis of tubercular granulomatous hypophysitis, despite the absence of caseous necrosis.

Implications:

• Highlights the importance of considering tuberculosis in all cases of granulomatous hypophysitis, especially in endemic areas.
• Emphasizes the need for high clinical suspicion for tuberculosis, even with negative AFB stains and non-caseating granulomas.
• Underscores the critical role of early and accurate diagnosis to prevent severe sequelae such as meningitis.