Transaminitis Evaluation Leads to the Incidental Diagnosis of Familial Paraganglioma Due to SDHB Mutation

Background: Paragangliomas are rare neuroendocrine tumors. Patients with succinate dehydrogenase subunit B (SDHB) gene mutations are predisposed to developing paraganglioma/pheochromocytoma. We are presenting the case of an incidental finding of a paraganglioma during an evaluation for transaminitis. Clinical Case: A 23-year-old male with a medical history of right hydrocele repair as a teenager was evaluated with an ultrasound of the abdomen for elevated liver enzymes and right upper quadrant discomfort. The ultrasound revealed a large lobular solid vascular 13.8 x 8.1 x 11.3 cm mass in the mid abdomen. He underwent a CT of the chest, abdomen and pelvis which demonstrated a large retroperitoneal mass measuring 16 x 10 x 13.7 cm within the right mid abdomen. The mass was described as a large centrally necrotic peripherally enhancing right retroperitoneal mass displacing the IVC anteriorly. The patient subsequently underwent an image-guided biopsy of the mass and the pathology revealed it was a paraganglioma. The patient denied any history of hypertension, orthostasis, headaches or palpitations. Biochemical workup for plasma catecholamines, plasma metanephrines, 24-hour urine catecholamines and metanephrines and cortisol were unremarkable. His transaminitis also resolved. He underwent a retroperitoneal paraganglioma excision and the final pathology was consistent with paraganglioma and negative for capsular invasion. He was referred to a genetic counsellor for testing since paragangliomas can be inherited. He also mentioned a family history of breast cancer in his mother and HTN and prostate cancer in his father. His test revealed that he had a c.289A>T mutation in his SDHB gene. He was encouraged to share the information with his family to help them understand the implications of his genetic test result. He underwent a surveillance PET scan which showed multiple osseous lesions in his temporal calvarium, sphenoid, spine and sacrum suggestive of metastasis. Repeat imaging with a DOTATATE PET scan showed stable disease. His transaminitis was transient, and we did not find a correlation to his paraganglioma. His imaging tests showed no liver metastasis. A CT of the head showed no evidence of intracranial metastasis. The current plan is to continue surveillance. His older brother underwent a genetic testing. He tested positive for the same SDHB mutation and underwent biochemical and imaging tests which were unremarkable. He too will continue surveillance. Conclusions: Patients with a succinate dehydrogenase subunit B (SDHB) gene mutations are predisposed to developing paraganglioma/pheochromocytoma. The tumors produce catecholamines, but can be biochemically silent as in our patient. They are inherited in an autosomal dominant manner. Our case highlights the importance for genetic counseling which increases the chances of early screening and surveillance in affected family members for optimal multidisciplinary management of patients.