Endocrine Abstracts

Background: Pituitary abscesses are rare and carry a high mortality risk. Recurrence of such abscesses is even rarer, with only 9 cases previously reported in the literature to our knowledge. We describe a case of a recurrent pituitary abscess, felt to be associated with inflammatory bowel disease. Case history, investigations, results and treatment A 27-year-old female presented with a right 6th nerve palsy associated with a 3-month history of headache post-partum. Further investigations revealed panhypopituitarism and a peripherally-enhancing cystic sellar mass, impinging on the optic chiasm. Initiation of steroid therapy unmasked diabetes insipidus, but her headache improved. Her WCC was expected, but her CRP elevated at 114 mg/L. She underwent an endoscopic pituitary biopsy, and frank pus was drained from the fossa. Gram staining was negative, but cultures later grew Streptococcus pneumonia and Staphylococcus epidermidis. She received empirical antimicrobial therapy. She recovered her pituitary hormones post-operatively, apart from her gonadal axis. A granulomatous inflammatory response and chronic lymphatic infiltrate were noted in Rathke’s cleft cyst on histology. Three years later, she developed a recurrence of her pituitary abscess associated with panhypopituitarism and diabetes insipidus. Pus was again drained, but microbiology cultures were negative. Soon after, she was diagnosed with Inflammatory Bowel Disease (IBD) when investigated for diarrhoea and mouth ulcers. She was treated with budesonide but suffered a flare-up of her IBD. She was then initiated on adalimumab, a monoclonal antibody used as a disease-modifying antirheumatic drug. Close biochemical and radiological surveillance of her pituitary remained satisfactory. 20 months later, she reported a minor headache. MRI of the pituitary fossa revealed a recurrence of her pituitary abscess but smaller than her previous episodes. Her pituitary functions were normal except for her known central hypogonadism. Her serum adalimumab level was undetectable and her anti-adalimumab antibody level elevated at >160 ng/mL (reference range <10). Given that her vision was not compromised by her recurrent pituitary abscess, she was started on high dose steroid therapy. Repeat imaging 3 weeks later demonstrated a significant reduction in the size of the pituitary mass. She is now established on azathioprine and infliximab as second-line immunosuppressive therapy and has stopped steroid therapy. Her surveillance imaging remains stable.

Discussion: Granulomatous hypophysitis associated with IBD is exceedingly rare. We demonstrate the role of immunomodulation in the acute management of recurrent pituitary abscess, felt to be associated with IBD with a high degree of certainty.