Endocrine Abstracts

Introduction: Pituitary infarction is rare in the paediatric age. In adolescents and adults it is often secondary to haemorrhage into an underlying lesion such as pituitary adenoma or cyst. Lymphocytic hypophysitis is rare in children and usually peri-tumoral due to germinoma, craniopharyngioma or Rathke’s cyst and often associated with hypopituitarism and diabetes insipidus.

Case report: An 11-year-old girl was admitted with a urinary tract infection (UTI) and sudden onset vomiting. She also had experienced frontal headaches, fever, low blood pressure, lethargy and 6 kg weight loss of 3 weeks duration. Symptoms seemed disproportionate to a UTI alone. Laboratory tests indicated normal electrolytes but low TSH 0.09 mIU/l (n 0.6–3.7) and morning cortisol <30 nmol/l (n>250) and mild elevation Prolactin 60 (n 0–42). MRI showed a normal sized anterior pituitary 7 mm with loss of the pituitary bright spot. After gadolinium, normal stalk but no enhancement on the delayed images suggesting a cystic lesion or infarction of the pituitary. MRI 1 month later showed the pituitary had halved in size and over 2 years progressed to an ‘empty sella’. Tumour markers, viral serology and tuberculosis screen were negative. Adrenal antibodies were negative. Pituitary autoantibodies by ITT (in-vitro transcription translation) assay for TPIT, CADPS, CHD8 and enolase were negative but positive for piccolo, a protein involved in dense-core vesicle transport. Hydrocortisone, thyroxine and GH replacement therapy was started and subsequently pubertal induction needed. She remains hypopituitary 10 years later.

Conclusions: No definite cause for pituitary infarction was found in an 11-year-old girl but pituitary autoantibodies reacted to the protein piccolo. We suspect this patient had hypophysitis related to a cystic lesion with resulting infarction of the pituitary. Pituitary autoantibodies may be epiphenomena and not causative.