A 25-year-old Laotian female, who lived in Thailand for ten years, presented with low-grade fever, sudden onset of headache, and rapidly progressive visual loss in both eyes for 5 days. There was no previous history of headache, chronic cough, weight loss, prolonged fever or history of exposure to tuberculosis. She gave birth to her second child 2 years before without any complications and successfully breastfed for 9 months, indicating intact hypothalamic-pituitary-gonadal axis previously.
On examination, the patient was alert and cooperative, but acutely ill looking. Vital signs were: body temperature 37.8  C, blood pressure 100/60 mmHg, pulse rate 60 beats/min and respiratory rate 16 breaths/min. Best corrected visual acuity was hand movements of the left eye and 20/40 of the right eye. Right temporal hemianopia was detected by Goldmann perimeter. Other cranial nerves and neurological examinations were normal. A magnetic resonance imaging (MRI) of brain showed rim-enhancing lesion, hypointense on T1-weighted image, mixed hypo- and hyperintense on T2-weighted image, occupying the sellar region with suprasellar extension, measuring about 1.4 x 2.5 x 2.2 cm (Fig. 1). Meningeal enhancement and thickened enhancement of pituitary stalk was seen with absence of posterior bright spot. The lesion compressed optic chiasm causing hyperintense signal in T2-weighted image of both optic nerves and optic chiasm. Chest x-ray was unremarkable. Anti-HIV and VDRL testing were negative.
Anterior pituitary hormone evaluation revealed panhypopituitarism; thyroid stimulating hormone 0.081 uIU/mL (0.35-4.94), serum free T4 0.71 ng/dL (0.70-1.48), early morning cortisol <1 mcg/dL, prolactin <0.6 ng/mL (5.18-26.53), insulin like growth factor-1 81 ng/mL (117-329). Hyponatremia with serum sodium of 124 mmol/L was found. With regular menstrual cycles by using oral contraceptive pill, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were not evaluated. Then the patient was initially treated adrenal insufficiency with intravenous hydrocortisone. Polyuria from central diabetes insipidus was unmasked after hydrocortisone therapy.
Due to acute visual loss, the patient underwent urgent endoscopic transphenoidal pituitary surgery. Thickening of dura mater was noted intraoperatively. A firm un-suckable mass at sellar and suprasellar region, appeared like caseous necrotic tissue, was found separately from normal adjacent pituitary gland. Decompression of optic chiasm and excisional biopsy of mass were performed. Histopathology showed necrotizing granulomatous inflammation with adjacent infarcted normal pituitary tissue (Fig. 2). Gomori Methenamine Silver stain and acid fast bacilli stain were negative. In addition, polymerase chain reaction (PCR) of Mycobacterium spp. was negative.
The combination of histological findings, enhanced pituitary stalk in post-contrast MRI and the fact that patient living in endemic area highly suggested the diagnosis of pituitary tuberculoma. Treatment was initiated with a 2-month combination of isoniazid, rifampin, pyrazinamide and ethambutol, followed by 7 months of isoniazid and rifampin. Mycobacterium and fungus culture were later reported negative. Hormonal replacement including prednisolone and levothyroxine were given. Short-term therapy of oral desmopressin was given for 3 weeks which was later stopped during follow up. Her headache rapidly resolved. She regained her 20/20 vision of both eyes within 1 week with only a small visual field defect in left periphery before discharge from hospital. Unfortunately, her secondary adrenal insufficiency and hypothyroidism are still persistent at 9-month follow-up.