8338 A Case Series Of 3 Patients With Unusual Miliary Lung Metastases In Paraganglioma: Diagnostic Workup, Treatment Challenges And Outcomes

Abstract Disclosure: K.M. Charles: None. M.A. Nazari: None. A. Jha: None. A. Derkyi: None. S. Talvacchio: None. M.J. Kuo: None. M. Patel: None. T. Prodanov: None. A.S. Alzahrani: None. A. Chen: None. J. Glod: None. J. Del Rivero: None. A.M. Gharib: None. K. Pacak: None. Background: Pheochromocytomas (PCCs) and paragangliomas (PGLs, together PPGLs) are uncommon neuroendocrine tumors originating from adrenal medulla chromaffin cells and sympathetic/parasympathetic ganglia. Metastatic disease occurs in a subset of PPGLs, ranging from 5% to 30% depending on the underlying genetic factors. Metastases are typically found in the bone, lung, lymph nodes, or liver. Historically, there have been no reported cases of PPGL with miliary pattern of pulmonary metastases. Methods: Three patients were identified with pulmonary metastases. All patients were evaluated between 2016 and 2023, and all developed extensive pulmonary metastatic disease. The evaluation process involved reviewing their medical history, laboratory results, and potential therapeutic approaches. Each patient underwent surgical intervention for the primary tumor and received systemic therapies once metastatic spread was detected. Results: We present three patients with either germline succinate dehydrogenase subunit D (SDHD) or von Hippel-Lindau (VHL) pathogenic variants who developed this rare condition. Patient 1: a 14-year-old female with right PCC and a recurrent left neck PGL carrying VHL type 2 pathogenic variant: VHL c.250G>T (p.Val84Leu) and received various chemotherapies with an unfavorable response. Patient 2: a 23-year-old female with a left jugular PGL carrying SDHD pathogenic variant: SDHD c.124_127delinsA TA (p.Glu42Ilefs*44). Patient 3: a 26-year-old female with a right PCC carrying a germline VHL type 2 pathogenic variant: VHL c.439C>G (p.Leu147Val). The latter two patients experienced disease stabilization through chemotherapy and systemic targeted radiotherapy, respectively. Discussion/Conclusion: This case series is unique as it highlights the rare occurrence of miliary spread of pulmonary metastases resulting from PCC or PGL. It also provides insight into prospective treatments options and outcomes for clinicians administering care within this population of patients. Though it is not clear at this time, this case series may represent a new subset of PPGL that have different genomic features and require a different therapeutic approach. Presentation: 6/1/2024