Endocrine Abstracts

Clinical presentation: We report a 46 year old female who presented with a 1 year history of bruising, thin skin and weight gain. In addition; she reported flushing of her chest, heat intolerance, palpitations and abdominal pain. On clinical examination she appeared cushingoid, blood pressure was elevated at 160/98 mm/Hg.

Investigations: Biochemical investigations indicated ACTH-dependent Cushing syndrome: 24 h UFC 300 μg (0–50), ACTH 119 pg/ml (8–42); midnight salivary cortisol 950 ng/dl (<100). MRI pituitary demonstrated a sellar lesion; 14×9×9 mm suggestive of a pituitary macroadenoma. To investigate the symptoms of flushing and palpitations, plasma fractionated catecholamines and metanephrines were performed and were elevated; norepinephrine 822 pg/ml (80–520), epinephrine <10 pg/ml (10–200), dopamine <20 pg/ml (0–20), normetanephrine 1250 pg/ml (18–101), metanephrine 34 pg/ml (12–67). CT abdomen revealed a lipid poor right adrenal mass measuring 17×36 mm with Hounsfield units of 47, consistent with a phaeochromocytoma.

Management: The patient started phenoxybenzamine and subsequently uptitrated the dose for three weeks prior to elective adrenalectomy. A robotic right trans-abdominal lateral adrenalectomy was performed without complications, histology confirmed phaeochromocytoma. One month post-adrenalectomy plasma fractionated catecholamines and metanephrines were normal. The patient continued to be hypercortisolemic post-op. 6 weeks after adrenal surgery transsphenoidal resection of the pituitary mass was performed, the histology revealed an adenoma which was diffusely positive for ACTH, it did not stain with any other anterior pituitary hormones. At 3 months post-pituitary surgery, she had normal plasma metanephrines and 24 h UFC levels with no visible residual disease on pituitary MRI.

Discussion: Phaeochromocytoma is associated with excess morbidity and mortality if undiagnosed, it was therefore fortuitous that this diagnosis was made prior to pituitary surgery. Clinicians should be alert to the about rare association of phaeochromocytoma in patients with clinically significant pituitary adenomas, and pursue further work up if clinically indicated.