Giant Cell Granulomatous Hypophysitis Mimicking a Giant Pituitary Macroadenoma

Abstract

Abstract: : Purpose: To present a case of giant cell granulomatous hypophysitis mimicking a giant pituitary macroadenoma and literature review. Methods: A case report Results: A 52–year–old Chinese female with no previous endocrine or autoimmune disease, presented with a history of blurring of vision in the left eye associated with headache. A bitemporal visual field defect was found. She underwent a MRI and was diagnosied as having a pituitary adenoma with suprasellar extension compressing the optic chiasma. She was also found to have panhypopituitarism. Interestingly, when she was listed for an endoscopic trans–sphenoidal excision of the tumour, intra–operative findings showed a yellow, firm lesion inconsistent with an adenoma and only a biopsy was performed. Histology revealed a diagnosis of giant cell granulomatous hypophysitis. Conclusions: Granulomatous inflammation of the pituitary gland is a rare disease. There is associated panhypopituitarism, and rarely hyperprolactinemia. It can present clinically to an ophthalmologist with a bitemporal visual field defect and thus mimic a pituitary macroadenoma. As it is hard to differentiate this difference based on radiology, most diagnoses are based on histology. Our patient's symptoms of headache and her visual field defect were relieved after the biopsy. However, her endocrine problem of panhypopituitarism remained.

Keywords: neuro-ophthalmology: diagnosis • inflammation • neuro-ophthalmology: cortical function/rehabilitation