An unusual case of phaeochromocytoma
MA Clarke, A Choo-Kang, M Cooper, S Kumar, P Dodson & A Rahim
A 62 year old woman presented in May 2001 with a one year history of palpitations. A 24 hour tape showed a short run of supra ventricular tachycardia only.
In December 2001 she was admitted with palpitations, presyncope and a labile blood pressure. Systolic pressures of 150-186mmHg and diastolic pressures of 95-112mmHg were recorded. 24 hour urine collection for catecholamines revealed normal adrenaline levels but elevated noradrenaline at 5265 nanomols per collection (normal range 76-561) and dopamine at 8950 nanomols per collection (normal range 866-2897).
Following an endocrine referral repeat 24 hour catecholamines showed similar levels. A diagnosis of phaeochromocytoma was made. A CT scan of abdomen and pelvis demonstrated a 1.5cm lesion within the left adrenal gland. A MIBG scan was negative. She was treated with phenoxybenzamine and beta blockade and underwent left adrenalectomy in August 2002.
She made a good post-operative recovery but histology confirmed a benign adrenal adenoma. Repeat urinary collections confirmed the continued high levels of noradrenaline and dopamine. MRI scanning was contraindicated so further investigation included a CT scan of the neck and thorax. This demonstrated a large mixed attenuation mass in the subcarinal region but no focal pulmonary abnormality. A biopsy of this mass was not diagnostic. An octreotide scan showed uptake within the thorax, right femur and abdomen. Subsequent x-ray of the right hip confirmed a lytic lesion but this was unsuitable for biopsy
The patient is currently awaiting labelled octreotide chemotherapy.
The biochemistry was consistent with an extra adrenal phaeochromocytoma whilst imaging demonstrated an adrenal tumour. However this subsequently turned out to be an adrenal incidentaloma. This demonstrates an unusual case of phaeochromocytoma and illustrates the diagnostic difficulties when dealing with a rare condition.