Endocrine Abstracts

Pituitary abscess is very rare accounting for 0.2 – 0.6% of all pituitary lesions. Only around 210 case reports have been described so far. We report a case of pituitary abscess presented as pituitary mass lesion with hypopituitarism.

A 51 year old man was admitted with headache and found to have severe hyponatraemia. Past medical history included paranoid schizophrenia. Clinical examination was normal.

Relevant investigations: sodium 110 mmol/l, 0900 h cortisol 21 nmol/l, free T₄ 5.1 pmol/l, TSH 0.34 mIU/l, LH 0.8 IU/l, FSH 3.4 IU/l, testosterone 0.6 nmol/l, prolactin 139 mU/l.

Pituitary MR revealed a macroadenoma measuring 20 mm and abutting the optic chiasm. Glucagon stimulation test confirmed secondary hypoadrenalism. Visual field tests showed bilateral superior upper quadrantanopia.

He was started on hydrocortisone, thyroxine and testosterone replacement for the hypoptuitarism. He was referred to the neurosurgical team. He underwent trans sphenoidal surgery. Creamy soft material drained. Histology revealed fluid with acute and chronic inflammatory cells consistent with abscess. He has received antibiotics. Post operatively he recovered well and headaches improved.

Conclusions:: Pituitary abscess usually occurs in pre-existing pituitary lesion. Predisposing factors usually include focus of parasellar infection. Usual presenting features include headache, visual defects, hypopituitarism, pyrexia and meningitis. MRI with contrast may show peripheral enhancement. Treatment is surgical drainage, antibiotics and hormone replacement.

Pituitary abscess is very rare, a potential cause of pituitary mass. Clinical diagnosis should be suspected with symptoms and signs of pituitary mass and infection. It’s often radilogically indistinguishable from other pituitary lesions. Correct diagnosis is difficult before the surgery.