Endocrine Abstracts

JOINT3947

Paragangliomas are rare neuroendocrine tumors that can arise in various locations throughout the body. While typically benign, these tumors can exhibit aggressive behavior and malignant potential, particularly when associated with genetic mutations. They can secrete catecholamines, leading to a range of adrenergic symptoms which further complicates their diagnosis and management. One of the most clinically significant mutations linked to hereditary paragangliomas involves the succinate dehydrogenase subunit B (SDH-B) gene. Patients with these mutations are at higher risk for malignancy and tumor recurrence, presenting unique challenges. We report the case of a 41-year-old patient with an abdominal paraganglioma harboring an SDH-B mutation, initially treated in January 2022 with both biochemical and imaging evidence indicating complete response. In August 2024, the patient presented with adrenergic symptoms and biochemical evidence of recurrence and was started on phenoxybenzamine. A thoracoabdominal-pelvic CT scan showed no signs of disease, but a subsequent gallium PET scan revealed a focal area of intense abnormal uptake in the posterior region of the left acetabulum, suggestive of metastatic paraganglioma. The case was discussed in a multidisciplinary team meeting, with the option for a targeted approach, based on the most recent clinical guidelines. Surgical intervention by the orthopedic team was deemed unfeasible due to the difficulty in accurately locating the lesion intraoperatively, and the only remaining surgical option- a total hip replacement—was associated with significant morbidity. Similarly, image-guided intervention was ruled out due to the risk of sciatic nerve injury. Subsequently the case was referred to radiation oncology, where stereotaxic radiotherapy was selected as the preferred treatment modality. This case highlights the elevated risk of recurrence in patients with SDH-B mutations and underscores the complexities involved in managing them, particularly due to the size, location, and metastatic potential of the lesions. A multidisciplinary approach is critical, as decision-making often requires input from various specialties to determine the most appropriate treatment plan. In patients with solitary metastases and low tumor burden, local control is typically the first-line option. Furthermore, this case emphasizes the importance of considering stereotaxic radiotherapy in the treatment of paragangliomas, a modality that may be underutilized.