Endocrine Abstracts

Introduction: Hyperprolactinaemia, amenorrhoea with ophthalmoplegia and radiological abnormalities in suprasellar region usually suggest a pituitary tumour. We present a case of carotico-cavernous sinus fistula causing pituitary engorgement (CCF) mimicking pituitary tumour.

Case history: 45 year old female with background history of long term amenorrhea, migraine admitted under Neurology with worsening headache, nausea, vomiting and blurred vision. There was no associated pyrexia, rash or diarrhoea. Other background history included PTSD, obesity, chronic fatigue syndrome, depression, hypothyroidism and fibromyalgia. She was on regular pericyazine, citalopram, levothyroxine, pregablin. Physical examination revealed bilateral chemosis, right eye proptosis with diplopia on right horizontal gaze consistent with right sixth nerve palsy.

Investigations: All initial investigations, including autoimmune screen for rheumatoid arthritis, SLE, were normal. MRI brain suggested a potential CCF and also a possibility of a suprasellar lesion. At this point endocrine input was sorted, hormonal testing indicated a moderately raised prolactin of 1906 mUI/l, low TSH 0.15 (0.35–3.50 mU/l) with T4 of 16 (8 – 21 pmol/l), LH 1.8 IU/l, FSH 3.5 IU/l, oestradiol 147 pmol/l, IGF1 14.8 (7.6–28.5 nmol/l), 0600 h cortisol 302 nmol/l. She subsequently had a dedicated MRI pituitary which was reported having a pituitary tumour with suprasellar extension. Her case was further discussed in radiology MDT and it was concluded that appearance was more in keeping with pituitary engorgement secondary to low cerebral pressure. This was confirmed on CT angiogram which showed CCF. She underwent bilateral cavernous sinus embolization with 35% precipitating hydrophobic injectable liquid and recovered slowly with a period of rehabilitation. Her prolactinaemia was likely from combination of stress and periciazine therapy. Repeat MRI was not carried out to see whether engorgement was resolved due to potential radiology interference of metal coils used in the embolization. Subsequent pituitary function tests were normal. Her menstrual period also returned spontaneously.

Conclusion: CCF is an abnormal communication between the cavernous sinus and the carotid arterial system. CCF may result in enlargement of the interconnecting components of the cavernous sinus around the pituitary fossa. Radiologically this can mimic pituitary enlargement/tumour thereby proving to be potential diagnostic pitfall. Careful history, clinical examination and multi-disciplinary approach are essential for correct diagnosis and management.