Treatment-resistant hypertension in a post-transplant patient with cystic fibrosis: A rare case of phaeochromocytoma

Abstract

Phaeochromocytoma is a rare catecholamine-producing tumour. We present the case of phaeochromocytoma in a young man with a background history of a double-lung transplant for cystic fibrosis (CF). Clinical case: A 25-year-old man, with a background history of CF, CF-related diabetes (CFRD) and a double-lung transplant in 2012 was presented to the emergency department with crampy abdominal pain, nausea and vomiting. He was diagnosed with distal intestinal obstructions syndrome (DIOS). Contrast-enhanced CT imaging of the abdomen and pelvis showed a 3.4 cm right adrenal lesion. This was confirmed by a subsequent MRI of adrenal glands that demonstrated moderate FDG uptake, suggestive of a diagnosis of phaeochromocytoma. The patient was noted to be hypertensive with a blood pressure averaging 170/90 mm/Hg despite treatment with three different anti-hypertensive medications - amlodipine, telmisartan and doxazosin. He had hypertension for the last 3 years and had noted increasingly frequent sweating episodes recently, without palpitations or headache. Laboratory analysis showed elevated plasma normetanephrines (NMN) of 3167 pmol/L (182-867) as well as elevated metanephrines (MN) of 793 pmol/L (61-377) and a high 3-MT of 257 pmol/L (<185). Once cathecholamine excess was identified biochemically, we proceeded to functional imaging to further investigate. MIBG scan showed a mild increase in the uptake of tracer to the right adrenal gland compared to the left. The case was discussed at a multidisciplinary (MDT) meeting at which the diagnosis of phaeochromocytoma was made. Following a challenging period of 4 weeks to control the patient’s blood pressure with an alpha-blocker and beta-blocker, the patient had an elective right adrenalectomy, with normalisation of his blood pressure post-surgery. The histopathology of the excised adrenal gland was consistent with a 3 cm phaeochromocytoma with no adverse features associated with malignant potential.