A 71-year-old female presented with acute right-sided chest/flank pain with blood pressure 103/66 mmHg and unremarkable biochemistry. Computed tomography (CT) scan of the chest/abdomen demonstrated right subsegmental pulmonary emboli and a 108mmx99mm heterogeneous lesion inseparable from the inferior vena cava (IVC) suspicious for a haemorrhagic right adrenal mass while the left adrenal gland was unremarkable. She had well-controlled hypertension (amlodipine monotherapy) and no history of diabetes, osteoporosis or episodes of sweats, headaches or palpitations.
Subsequent outpatient adrenal functional screen was unremarkable with normal plasma normetanephrines 430 pmol/L (<1280), metanephrines 90 pmol/L (<447) and 3-methoxytyramine 110 pmol/L (<181), late-night salivary cortisol 3 nmol/L (<8) and aldosterone/renin ratio 21 (<70). Progress CT abdomen showed an 88x64x68mm right homogeneous adrenal mass with resolution of haemorrhage. 18F-FDG-PET/CT scan demonstrated the right adrenal mass had diffuse intense FDG-avidity (SUVmax 20.2) with no other focal abnormal FDG-avidity.
She was re-admitted for open right adrenalectomy for presumed non-functioning adrenocortical cancer. The right adrenal mass was adherent to the IVC and diaphragm requiring partial resection. She had intraoperative and immediate (<24 hours) post-operative hypotension requiring metaraminol. She was covered with hydrocortisone which was later ceased given robust morning cortisol level (283 nmol/L) off glucocorticoid therapy.
Surprisingly, histopathology demonstrated a completely resected 120mm phaeochromocytoma with tumour cells arranged in small nests with areas of sheet-like growth and low mitotic count (1/10 per hpf). There was extensive haemorrhagic and cystic change in the centre of the lesion and the tumour invaded into the peri-adrenal soft tissue and IVC lumen. Tumour cells demonstrated positive staining for synaptophysin and chromogranin-A with Ki-67 index of 5%. Staining for SDHA and SDHB and fumarate hydratase were intact however weakly positive staining for 2SC raised suspicion for fumarate hydratase-deficient phaeochromocytoma.
Results of 68Ga-DOTATATE-PET/CT scan to exclude multifocal/metastatic disease and germline phaeochromocytoma panel will be presented.