Endocrine Abstracts

We report a case of 43 year old gentleman who had surgery in 1998 for left glomus typanicum, leaving him with complete left lower facial nerve palsy. Incidentally he was noted to have had labile blood pressure during this surgery. He had gradual growth of residual tumour which required fractionated radiotherapy in 2012. He has had ongoing problems with headaches with profuse left-sided rhinorrhoea and intermittent episodes of sweating. In February 2016 he was referred to ENT for evaluation of his symptoms. His urinary catecholamines showed methoxytyramine 5.17 umol/24 hr (reference range succinate dehydrogenase B (SDHB). A likely indolent left level IIb nodal metastasis was identified on FDG PET scan. The iodine-123-meta-iodobenzylguanidine (M IBG) scan demonstrated no increase uptake in the lesion. However, a skull base mass lesion and lymph nodes were avid on 68-Ga- DOTATATE PET CT. This is in keeping with recent finding that lesions due to SDHB mutations are more likely to be avid on 68-Ga-DOTATATE scans. The patient was symptomatic and the biochemical markers confirmed the lesion to were functional (no other lesions were identified on scans). The utility of the Ga-68 DOTATE PET scan has provided a treatment option Lutetium based Peptide Receptor Radionuclide Therapy (PRRT).

This case highlights that, though rare, head and neck paragangliomas can be secretory. Furthermore, the utilisation of appropriate functional imaging can be quite important in the treatment pathway. Genetic testing was carried out relatively late during the course of the management of this patient which may have given important information about likely course of the disease as well as imaging modalities that may have been useful in the detection of the disease.