Endocrine Abstracts

Section 1: Case: A 42-year-old woman developed central chest pain four hours after undergoing right mastectomy for intraductal breast carcinoma. Serial blood pressures were recorded as significantly elevated, up to 240/130mmHg. There was no history of new-onset headaches, palpitations, anxiety, hirsutism, change in weight or easy bruising. She had no other significant past medical history or family history.

Section 2: Investigations : An electrocardiogram was normal and troponin levels were not elevated. A computer tomography pulmonary angiogram was performed which excluded pulmonary embolism (PE), but also revealed a large (12 cm x 6.6 cm) left-sided retroperitoneal mass. Plasma normetanephrine and metanephrine levels were not elevated. Renin and aldosterone levels were raised at 243ng/l and 1490pmol/l respectively, ratio 2pmol/mg (RRs: 0.5-3ng/l and 90-700pmol/l). FDG-PET scan showed an intensely avid area within the lesion, with no other sites of FDG uptake. Repeat measurement of plasma metanephrines included 3-methoxytyramine levels which were significantly raised at 21 906pmol/l (RR <180pmol/l).

Section 3: Results and treatment : The results primarily raised concern for adrenocortical carcinoma. Initial imaging showed central necrosis within the suspected tumour with marked peripheral vascularity, with the mass encasing the renal artery. The renin:aldosterone ratio did not indicate primary aldosteronism. However, 3-methoxytramine levels were strongly indicative of phaechromocytoma or paraganglioma. The patient underwent left adrenalectomy and nephrectomy. Histology confirmed a moderately differentiated paraganglioma with evidence of capsular and vascular invasion with a Ki-67 index of between 18-20%, which was excised completely. The patient’s hypertension was treated successfully with alpha blockade using doxazocin. A Gallium Dototate PET-CT scan was carried out four weeks after surgery. This showed no tracer avid disease. Genetic testing confirmed succinate dehydrogenase gene subunit A (SDHA) related Hereditary Paraganglioma-Phaechromoctyoma Syndrome (HPPS). Future imaging surveillance will consist of annual whole body and neck MRI. The patient underwent genetic counselling to discuss screening and surveillance for her brother and two primary school-aged children.Section 4: Conclusions and points for discussion We describe a case of HPPS and malignant paraganglioma, diagnosed during active treatment of a separate primary malignancy. The case illustrates the challenges in diagnosis at varying stages of investigation. Here, a hypertensive crisis, which is well-known to occur with paraganglionoma and phaeochromocytoma, occurred as an index event, but the incidental finding on imaging for PE was key to elucidating the diagnosis. This case also highlights the diagnostic value of 3-methoxytramine and issues that may arise around genetic counselling.