Endocrine Abstracts

Case history: A 72 year old gentleman from Zimbabwe presented to clinic with MRI pituitary findings of 1.5×1.4×1 cm pituitary macroadenoma. This had been discovered incidentally during outpatient investigation for severe headaches refractory to standard analgesia at another hospital. The mass was in contact with but not compressing the optic chiasm. He did not describe any visual loss. He had an unintentional weight loss of 10 kg in the last 2 months. He described decreased libido for the last 3 years and no erections including the mornings. He has no other past medical history other than glaucoma. Examination of the testes revealed small testes bilaterally approximately 6–8 ml in volume. Visual fields were minimally decreased temporally to confrontation with red pin.

Investigations, results and treatment: Pituitary profile revealed a raised prolactin of 19 204 mU/l (0–496) after PEG precipitate. The rest of his anterior pituitary function was within normal limits. Testosterone was suppressed at 1.6 nmol/l (9–27). PSA was raised at 4426 mcg/l (0–4.4) and liver function revealed a raised ALP of 758 U/l (30–130). On the basis of these blood tests he was diagnosed with a macroprolactinoma and metastatic prostate cancer and referral to oncology was made.

Whole body CT and bone scans revealed widespread bony disease including a burden of disease in the skull. He was started on docetaxel and also cabergoline. His headaches improved but after his PSA dropped but after some time his testosterone level started to rise. Cabergoline was stopped and he remains headache free. He has not had any visual disturbance and MRI pituitary reveals no compromise of the optic chiasm. His prostate cancer disease burden is currently stable on enzalutamide 18 months on from diagnosis.

Conclusion and points for discussion: This case describes a gentleman with metastatic prostate cancer who is biochemically castrate secondary to a macroprolactinoma. The management dilemma of this case is balancing the treatment of each as they are interrelated and how best this should be done.