Endocrine Abstracts

Paragangliomas are rare neuroendocrine tumours that originate from neural crest cells and can arise from any autonomic ganglion of the body. This is a challenging entity given the limited therapeutic options. Here, we present a rare case of metastatic Paraganglioma in a patient with a germline pathogenic succinate dehydrogenase subunit B (SDHB) mutation. A 54 year old lady was initially diagnosed with functioning bladder paraganglioma with raised metanephrine and normetanephrine level, which was treated with open radical cystectomy and lymph node dissection after appropriate alpha and beta blockage. Postoperative MIBG scan did not show any convincing residual or metastatic disease and biochemical work up revealed normalisation of metanephrine levels post operatively. Patient remained under regular follow up and had routine surveillance scans and continued to remain asymptomatic. 3 years after the initial diagnosis, she presented with symptoms of palpitations, pounding sensation in her neck and excessive seating.Surveillance scan picked up multiple lung nodules, a soft tissue nodule in the posterior right para renal space, an acetabular lesion in the left hip and a new lytic lesion in L1 vertebral body with grade 1 pathological fracture. Blood work up showed elevated plasma metanephrine level. Clinically she was hypertensive with resting tachycardia and was commenced on appropriate alpha (Doxazocin)and beta (Bisoprolol) blockage. She was discussed in the MDT with input from multiple specialities and it was decided to treat her with Peptide receptor radio nucleotide therapy (PRRT) using Luteum Dotatate, which is one of the latest modality of treatment There is growing body of evidence that PRRT is highly effective in terms of tumour response, disease stabilisation, symptomatic control and preservation of quality of life with favourable safety profile\. She has currently completed 2 cycles of the therapy and is awaiting FDG PET-CT and Gallium dotatate PET scan to assess response to treatment 8 weeks after the 2 nd cycle. Neurosurgical team advised conservative management of the vertebral fracture. She is also considered for prophylactic radiotherapy to the left acetabular lesion to prevent any fracture in the future. Multi disciplinary team approach remains indispensable given the complex nature of the condition.Patients with SDHx mutation, especially SDHB, have increased risk of developing metastasis and hence require regular, long-term surveillance. For patients with progressive or symptomatic disease that is not amendable to surgery there are various palliative treatment options like radiotherapy, radio frequency or csystemic therapies like chemotherapy or molecular targeted therapies like PRRT.