SUN-511 - Utility of DOTATATE PET/CT for Localizing Metastatic Pheochromocytoma After Initial Surgical Cure

Background: Pheochromocytomas are rare, catecholamine-producing neuroendocrine tumors originating from chromaffin cells of the adrenal medulla. While commonly presenting as benign, localized tumors, approximately 10–25% develop metastatic disease, usually in lymph nodes, bones, liver, and lungs. The clinical course is highly variable, ranging from indolent to rapidly progressive. Approximately 40% of cases are associated with germline mutations—most notably SDHB. We present a case of metastatic pheochromocytoma highlighting the diagnostic performance of DOTATATE PET/CT.

Case: A 52-year-old female with a history of pheochromocytoma diagnosed in 2017 presented with biochemical and radiographic evidence of metastatic recurrence following an initial curative resection. Her initial presentation included episodic hypertension, palpitations, diaphoresis, and markedly elevated plasma and urinary catecholamines. Imaging revealed a 5.4 cm right adrenal mass. She underwent adrenalectomy complicated by vascular involvement requiring right nephrectomy. Pathology confirmed pheochromocytoma without aggressive features. Postoperatively, symptoms resolved and metanephrines normalized, with sustained biochemical remission through 2020.

In 2022, plasma metanephrines and epinephrine levels were mildly elevated, with further increased in 2023. CT scan showed a soft tissue density posterior to the IVC which was further evaluated with Cu-DOTATATE PET/CT, which identified a right iliac lesion concerning for metastasis; However, the biopsy was negative. Serial imaging from 2025–2026 revealed progressive, multifocal DOTATATE-positive skeletal lesions involving the pelvis, femur, ribs, and spine, accompanied by rising plasma and urinary metanephrines and chromogranin A. Notably, the patient remained minimally symptomatic despite significant disease burden. Despite a negative biopsy, findings remained highly concerning for metastatic disease. Germline genetic testing for hereditary pheochromocytoma/paraganglioma syndromes was negative.

The patient was initiated on alpha-blockade and bone-directed therapy, with plans for somatostatin receptor–targeted therapy (lanreotide) and consideration of peptide receptor radionuclide therapy.

Discussion: This case highlights delayed metastatic recurrence despite initial biochemical remission and benign pathology, illustrating the importance of long-term surveillance and the diagnostic utility of functional imaging in detecting metastatic pheochromocytoma.

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