Endocrine Abstracts

Background: Pituitary abscess is a rare entity which is often not suspected in pituitary lesions differential diagnoses; arising de novo or as a consequence of sinus infection, meningitis, or haematogenous spread. The diagnosis is challenging and mostly made during surgery.

Case Report: A 54-year-old male patient presented with 3 days of severe headaches, vomiting, and left eyelid drooping. He was afebrile, BP 90/61mmHg, and had a left third nerve palsy with a superior visual field defect. Investigations showed hyponatremia 126mmol/l, cortisol 33nmol/l, prolactin 29mU/l, LH 0.6 iU/l, FSH 4 iU/l, Testosterone < 0.4 nmol/l, TSH 0.57 mU/l, FT4: 13.4pmol/lm CRP 167 mg/l. He was resuscitated with intravenous fluids and hydrocortisone. OCT showed normal optic nerve. A pituitary MRI scan showed a 14 x 23 x 16 mm heterogeneous mass displacing the optic chiasm in contact with the left ICA. A diagnosis of pituitary macroadenoma with apoplexy was made. After initial conservative management, his visual dysfunction was thought to be worse than the volume of the adenoma leading to a suspicion that there may have been an additional process causing nerve irritation from a combination of direct pressure and inflammation. Hence early surgical decompression was reconsidered to facilitate resolution of third nerve palsy. During endoscopic decompression, pus was drained. Microbiology revealed Staphylococcus Lugdunensis sensitive to cotrimoxazole and flucloxacillin and histology showed an infarcted FSH-secreting adenoma. He was commenced on antibiotics for 6 weeks duration.

Conclusions: Pituitary abscess is a rare potentially life-threatening condition with few distinct features to that of pituitary lesions presenting acutely. Presurgical diagnosis is uncommon and thus pituitary abscess should be considered in this clinical scenario.