Pituitary tuberculomas are extremely rare, even in the developing countries where tuberculosis is endemic. We report a rare case of isolated pituitary tuberculoma mimicking a pituitary adenoma or a Rathke's cleft cyst in Japan, a developed country. The patient was a 69-year-old woman presented with visual disturbance. Head magnetic resonance imaging (MRI) with contrast enhancement revealed an isolated intrasellar mass showing central hypointensity with an irregularly enhancing rim. She was operated on via an endoscopic transsphenoidal approach. Histopathological findings and an interferon-gamma release assay were highly suspicious of an isolated tuberculous granuloma. After proper infection control management, she was treated with four-drug antituberculous therapy (ATT). Follow-up MRI showed no recurrence 3 years after the discontinuation of ATT. An isolated pituitary tuberculoma has rarely been reported, especially in developed countries. In conclusion, neurosurgeons should consider an isolated pituitary tuberculoma as one of the differential diagnoses for pituitary tumors, because special management for infection control is required for tuberculosis. An interferon-gamma release assay is helpful for the difficult diagnosis of an isolated pituitary tuberculoma with inactive tuberculosis.
Keywords: antituberculous therapy; interferon-gamma release assay; intracranial tuberculosis; pituitary tuberculoma; pituitary tumor.