Endocrine Abstracts

Introduction: Paragangliomas (PGLs) are extra-adrenal, neural crest-derived neuroendocrine tumours. There are sympathetic (usually abdominal and thoracic regions) or parasympathetic PGLs (head and neck). Catecholamine excess usually occurs in sympathetic PGLs.

Case: A 34-year-old lady initially presented with left-sided neck swelling. She was diagnosed with left cervical PGL which was excised. Twenty years later, she noticed another lump in the same region and functional imaging indicated a second primary disease and underwent repeat surgery. Subsequent genetic testing revealed the succinate dehydrogenase enzyme D (SDHD) mutation. Her sister was also diagnosed with cervical PGL. Two years after surgery, she described daily intermittent forceful palpitations and was hypertensive with BP 170/95. Urinary catecholamine collections, plasma normetanephrine and metanephrine levels were normal. She had anatomical CT and MRI imaging, octreotide isotope scan and MIBG scintigraphy. Functional imaging revealed multiple sites in her mediastinum and her case was discussed at the regional neuroendocrine tumour meeting. As she was intolerant of phenoxybenzamine, doxazosin was started followed by propranolol. She had surgical removal of the right cervical, subclavian and aortic root PGLs. Recently, she was admitted with central chest pain associated with elevated cardiac enzymes. ECG demonstrated lateral ST depression, and an echocardiogram showed mid to apical, segmental and lateral wall hypokinesis with apex ballooning. Coronary angiography revealed normal arteries. Repeat echocardiogram showed ventricular function had returned to normal. A diagnosis of Takotsubo cardiomyopathy was made. Urinary catecholamine, plasma normetanephrine and metanephrine levels were normal throughout.

Conclusions: Head and neck PGLs are usually non-functioning and present as space-occupying symptoms. It is unusual she had symptoms of catecholamine excess. Functional imaging proves invaluable and this highlights the need to discuss complex cases in multidisciplinary meetings. With reported associations between Takotsubo cardiomyopathy and catecholamine-producing PGLs and phaechromocytomas, could this episode be a manifestation of her PGL? There should be a low threshold for functional imaging for PGLs in patients with familial genetic mutations.