Endocrine Abstracts

A 22 years old woman, with secondary infertility, was found to have secondary hypothyroidism and referred to endocrinology. On review her symptoms consisted of headache for 6 months, amenorrhoea, weight gain and progressive loss of vision in the left eye for 6–9 months, which had been investigated by opticians and opthalmologists. Other history includes Von Willebrand disease type2. Clinical examination confirmed total loss of vision of the left eye and complete temporal defect in the right.

Investigation: Biochemistry confirmed secondary hypothyroidism with adrenal insuffieciency –serum FT₄ 5.1 pmol/l (12–22), TSH 0.72 mIU/l (0.27–4.2). A short synacthen test confirmed adrenal insufficiency with a plasma ACTH level of 8.6 ng/l, basal serum cortisol of 142 nmol/l rising to only 344 nmol/l at 30 min after 250 μg ACTH 1–24. Serum prolactin was normal, but serum oestrodiol, LH and FSH were low, consistent with secondary gonadal failure. Gadolinium-enhanced MRI confirmed a pituitary macroadenoma measuring 27 mm×27 mm×17 mm and extending to the suprasellar cistern and compressing the optic chiasm and left optic track with possible recent apoplexy. No sinus abnormality was seen.

Management: Appropriate replacement therapy was commenced. After discussion endoscopic transsphenoidal surgery was performed. Unexpectedly during surgery pus was encountered on first incision of the pituitary mass, resulting in decompression of the optic chiasm. Culture was negative. Histopathology revealed benign squamous epithelial metaplastic cystic lesion with acute on chronic inflammation, consistent with a Rathke’s cleft cyst. Post-operatively she required desmopressin and full anterior pituitary replacement therapy. Remarkably her vision improved immediately after surgery and three months had returned to normal. Repeat MRI scan showed no evidence of recurrence of the cystic pituitary mass after 3 months of surgery.

Discussion: Complete recovery of vision after such an extended period of compression due to pituitary mass is unusual and fortunate in this case. Extensive squamous metaplasia in the Rathke’s cleft cyst is unusual and it appears that this had undergone degenerative change with the formation of sterile pus, but the cause of this unusual presentation is unclear.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.