SUN-405 Paraganglioma Originating Within the Maxillary Bone

Abstract E. Chuki: None. K. Saleh Anaraki: None. A. Derkyi: None. S. Talvacchio: None. A. Jha: None. K. Pacak: None. Introduction: Paragangliomas (PGLs) are typically neoplasms that develop from neurosecretory cells, believed to originate from the neural crest. Primary intraosseous PGLs are uncommon given the rarity of paraganglionic tissue within bone structures. We report the first instance of primary tumor arising from a bone. Clinical case: A 30-year-old woman presented with right facial pain and swelling along with palpitations; physical examination highlighted a tender and swollen right maxillary area. CT imaging showed a 33x31x23 mm heterogeneously enhancing mass arising from anterior maxilla. Endocrine labs revealed elevated plasma levels of dopamine [620 (normal <30) pg/mL)], 3-methoxytyramine [195 (normal <20) pg/mL], and chromogranin A [156 (normal <93) ng/mL)]. Plasma catecholamines and metanephrines were within normal range. The differential diagnoses encompassed neoplasms such as ameloblastomas, odontogenic tumors, and potential metastatic bone lesions from any primary including PPGL, in addition to infectious and inflammatory conditions. Biopsy of the lesion was performed and confirmed a PGL, demonstrating specific marker expression of synaptophysin, chromogranin, and GATA-3, along with retained expression of SDHB. Functional imaging using PET/CT studies identified the lesion as intensely 18F-FDOPA avid, faintly avid on 68Ga-DOTATATE, and hypermetabolic on 18F-FDG. No other lesions, either primary or metastatic were identified. Given the potential complications and aesthetic concerns associated with surgical intervention, a decision was made in favor of proton radiation therapy. She received a total of 54 Gy to the right maxilla. Post treatment, patient experienced significant symptom relief, a notable reduction in dopamine levels (469 pg/mL) and normalization of chromogranin A. Minimal growth of the lesion was observed during the 10-month follow-up. Conclusion: In the absence of any primaries on PET/CT imaging, this maxillary bone lesion was classified as a rare case of primary bone PGL. The hypothesis regarding the occurrence of primary PGLs in unconventional locations, such as bone, may be attributed to an increased dispersion of paraganglia during fetal development, potentially causing the formation of PGLs as individuals age. Given the similarities with other tumors, the role of immunohistochemistry and PPGL-specific PET/CT imaging is pivotal in reaching a diagnosis. Positive staining for proteins such as chromogranin A and synaptophysin as well as tumor’s 18F-FDOPA and 68Ga-DOTATATE avidity is paramount for confirming the diagnosis. This case of an exceedingly rare primary bone PGL (right maxilla) emphasizes the importance of a comprehensive diagnostic approach that combines physical examinations, biochemical testing, advanced imaging, and histopathological analysis. Such an approach is essential for providing personalized treatment options. Sunday, June 2, 2024