ESPE Abstracts

Background: Paragangliomas are rare tumours that originate from neural crest cells. Diagnosing and managing patients with paragangliomas pose several challenges.

Objective: We investigated whether MECP2 defects are associated with an idiopathic CPP phenotype with or without mild neurodevelopmental abnormalities.

Clinical presentation: A 14-year-old female presented with consecutive development of bony lesions lasting for more than 2 years before definitive diagnosis. MRI of the initial bony lesion was suggestive of osteomyelitis, biopsy was suggestive of chronic recurrent multifocal osteomyelitis. Bony lesions continued to develop, bone marrow did not reveal abnormal cells, and was negative for synaptophysin and chromogranin. She experienced a few episodes of abdominal pains and headaches but no reported sweating, palpitations, or tremors. Two years after the initial presentation, she had acute cardiovascular collapse, was admitted to PICU, and needed inotropic support. Repeated imaging showed pulmonary nodules and new bony lesions involving the left parietal bone, a biopsy of which showed granulation tissue with no evidence of malignancy. While on inotropic support, plasma normetanephrine and plasma 3-methoxytyramine were 22500 and 188 pmol/L respectively. A PET CT showed PET-avid lesions and a biopsy from a rib lesion finally revealed findings consistent with a paraganglioma with strong and diffuse positive staining with NSE, chromogranin, and synaptophysin. A repeat plasma normetanephrine and plasma 3-methoxytyramine were 20600 and 257 pmol/L respectively. An MIBG scan showed an MIBG-avid para-aortic/aortocaval mass, suspected to be the primary lesion. Genetic testing revealed a heterozygous variant of the SDHB gene NM_003000.2:c.423+1G>A Alpha blockade was commenced in incremental doses then beta blockade was added. Her blood pressure was successfully controlled, with a postural drop, in preparation for further treatment. The family was counselled about the diagnosis, therapeutic options, and the relatively unfavourable prognosis. Challenges discussed in the NET MDT meeting included that the lesions were not amenable to surgical excision, MIBG therapy was the most suitable for her but was not available so Lutetium dotatate therapy (LuDO) was pursued as a clinical trial, which requires isolation for radioisotope administration at another centre, and the importance of genetic counselling in an extended and complex family. The girl was reluctant to agree to treatment and struggled in the hospital setting but with support from the MDT, both the patient and her mother agreed to receive targeted radionuclide therapy.

Conclusion: This case highlights the challenges in diagnosing metastatic paragangliomas, which should be considered in the differential diagnosis of multiple bony lesions of uncertain aetiology. It illustrates the practical challenges in treating such a rare case in paediatrics.