Endocrine Abstracts

Introduction: Pheochromocytomas (PCCs) and paragangliomas (PGL) are rare but unique tumors. Only 10% of PCCs are malignant, defined by metastases. Metastases can be seen at diagnosis of the primary tumor or develop even 20 years later. Approximately half of patients with metastatic PCC/PGL have inherited SDHB mutations.

Case report: A 45-year-old man was referred to Urology for curvature of the penis and painful erections. Among his medical background highlighted high blood pressure and herniated disc intervened twice. Abdominal US revealed a large heterogeneous lesion in the right suprarenal region. A CT scan of the abdomen revealed a 9x5.8x6.1 cm heterogeneous right suprarenal mass. Laboratory analysis showed elevations in urine fractionates metanephrines (771 mg/24 h [25–312]) and normetanephrines (1425 mg/24 h [35–445]) levels. ^I-123 MIBG scintigraphy revealed uptake in the right adrenal region. Two months after diagnosis blood pressure figures were raised, being difficult to control.Phenoxybenzamine was used for preoperative preparation prior to surgical resection. Nephrectomy and right adrenalectomy were performed. Histopathology confirmed pheochromocytoma with lymph nodes metastasis. At six months follow-up, 4 right retrocrural lymph nodes metastasis of 7–10 mm were detected in CT scan and confirmed by 18F-dopa PET. ^I-123 MIBG scintigraphy did not reveal any uptake. Surgery was performed by high right para-aortic lymphadenectomy. Histopathological examination confirmed the diagnosis of pheochromocytoma metastasis in three nodes. Six months after surgery a follow-up 18F-dopa PET/TAC detected a 8-mm right retrocrural lymphatic metastasis with a maxSUV of 2.8. Catecholamines and metanephrines levels were within the normal range and blood pressure was controlled with enalapril. The genetic study performed in peripheral blood (SDHB) and tumor piece (SDHB, SDHC, SDHD, SDHA, SDHAF1, SDHAF2, RET, MEN-1, VHL, NF1, KIF1, BETA, MAX, TMEM127, MDH2, FH, EPAS1, HRAS) did not show genetic alterations. A 18F-dopa PET/TAC performed 4 years after the first surgery detected a retrocrural lymph node metastasis of 3 mm with a maxSUV of 2.2.

Conclusion: Complete resection is the only curative treatment in metastatic disease. Given the often indolent nature of the disease, other therapies (mainly 131I-MIBG, chemotherapy and/or radiation) are reserved for patients with severe symptoms or clear progression. A wait and see policy is recommended as first-line management in asymptomatic patients. The management of these patients requires a multidisciplinary follow up. Eventually a better knowledge about genetics might lead us to find better targets for therapy.