Endocrine Abstracts

Case history: A 64-year-old male was admitted to our hospital in January 2024 following a road traffic accident. The patient was not wearing a seatbelt, and airbags did not deploy due to low speed, resulting in the patient’s head hitting the windscreen. A subsequent CT trauma series showed a large destructive expansile lesion within the clivus and sphenoid bone extending superiorly into the hypothalamus with findings typical of a chordoma. Appearance on non-contrast MRI was also consistent with a chordoma. Imaging was reviewed by the local Neurosurgical centre and a pituitary profile requested, which unexpectedly showed a prolactin level of >100,000 munit/l and an elevated IGF-1 level of 78.6 nmol/l. Symptoms and features of acromegaly (macroglossia, increase in hand and foot size) and low testosterone (erectile dysfunction and low libido) became apparent following review by the Endocrine team.

Investigations: Due to patient claustrophobia initial MRI scans of the brain and whole spine were performed without contrast, but these showed no other spinal pathology other than a 50 × 40 × 76 mm lesion centred on the clivus. A CT chest, abdomen and pelvis was normal, showing no solid organ, lung or bony mass lesions (concern that clival lesion may be a metastasis). Visual field testing showed a possible left inferior arcuate defect (no bitemporal hemianopia). Pituitary function testing revealed normal thyroid and cortisol axes, and hypogonadotrophic hypogonadism consistent with hyperprolactinaemia. An oral glucose tolerance test (OGTT) confirmed acromegaly with failure to suppress growth hormone.

Results and treatment: The patient was initially treated with cabergoline 250 mg twice weekly and showed good biochemical (prolactin reduced to 98,510 munit/l) and radiological response (reduction in tumour size on repeat MRI) but discontinued therapy after three weeks due to an acute change in mood with depression, poor sleep and dark thoughts. The patient was not keen to restart cabergoline, and so testosterone replacement was commenced to try to ameliorate some of these psychological symptoms. Lanreotide was commenced once acromegaly was confirmed by OGTT. Despite concerns, there was no evidence of any CSF leak, and the current plan is to assess tumour response to medical therapy prior to surgical intervention. Surgical treatment and definitive diagnostic biopsy results are awaited.

Conclusions and points for discussion: Ectopic pituitary adenomas (in this case a lactosomatotroph adenoma) are a rare entity and can be mistaken for a chordoma. A definitive histopathologic diagnosis is awaited in this case.