A 14-year-old female was initially referred with an 18-month history of lethargy, reduced appetite, abdominal pain, bloating and nausea. She developed a headache at a later stage that was not associated with vomiting, visual symptoms or neurological deficit. Her significant concerns at presentation were primary amenorrhoea and lack of pubertal progression reporting no progressive breast development since 11 years. On examination her height was 151 cm (-1.73 SDS) and weight was 33 kg (-3.36 SDS) with a BMI of 14 kg/m2 (-3.03 SDS). Her pubertal assessment showed her to be at Tanner breast stage 3, with no axillary or pubic hair. A previously performed thyroid function test had revealed a low free thyroxine (T4) (8.9 pmol/l) and an inappropriately low TSH (2.3 IU/l) suggestive of central hypothyroidism. Subsequent dynamic pituitary function tests confirmed anterior hypopituitarism (Table 1) and she was commenced on hydrocortisone (10 mg/m2) and levothyroxine (50 mug daily) replacement. Steroid replacement unmasked her background diabetes insipidus both clinically and biochemically (Table 1) and she was commenced on desmopressin 100 mug twice daily. Her TW3 bone age was delayed by 2 years. Formal visual assessment showed bitemporal quadrantanopia worse on the left than on the right. Cranial magnetic resonance imaging (MRI) revealed a suprasellar mass compressing the optic chiasm with a relatively uniform high-signal intensity on T1- and T2-weighted sequences (Fig. 1A and B). Differential diagnoses considered based on these findings were pituitary macroadenoma, CP or a Rathke's cleft cyst. Endoscopic transsphenoidal surgery was performed in order to preserve her vision and obtain a formal diagnosis. Histopathology of the resected lesion showed reactive changes with necrotic material and cholesterol clefts suggestive of xanthogranuloma of the sellar region. Haemosiderin was observed and, although multinucleate cells were around some cholesterol clefts, these were not prominent (Table 2 and Fig. 4A). Gram stain (for bacteria), Warthin-Starry stain (for treponemes) and Ziehl-Neelsen stain (for TB) were all negative. Histology did not demonstrate evidence of vasculitis or granuloma formation, therefore ruling out sarcoidosis and Wegener's granulomatosis as the other biochemical tests were not performed.
She made an excellent recovery following hormone replacement and surgery. She has shown remarkable catch up growth (height velocity 9.36 cm/year) following growth hormone (0.7 mg/m2 per day) treatment. She is due to commence oestrogen replacement. An MRI scan performed 6 months post-surgery demonstrated significant decompression of the chiasm and a thin line of pituitary tissue in the base of the pituitary fossa.