Endocrine Abstracts

A 24-year old female patient was referred to the endocrinology department after discovery of a left adrenal tumor measuring 4×5 cm, on a CT-scan performed for recurrent back pain. She had a history of lower extremity lymph-oedema since the age of 13 years and juvenile xanthogranulomas operated at the age of 2 years. The tumor had a high density in native CT sequences (48 Hounsfield Units). MRI showed T1 iso-intensity and T2 hyper-intensity, as well as lymph nodes of the celiac trunk. 24-h urine metanephrines were 5 times higher than the upper limit of normal range. I¹²³-MIBG-scan was negative. The patient also fulfilled clinical criteria for type 1 neurofibromatosis (NF-1, Von Recklinghausen disease). After preparation with alpha-adrenergic blockers, a laparoscopic left adrenalectomy was performed. Histology showed composite pheochromocytoma with 30-40% differentiated neuroblastoma, exhibiting a Mib-1 proliferation index of 10-20%. Postoperative plasma-fractionated metanephrines were negative and I¹²³-MIBG-scan as well as PET-CT were normal. Genetic testing did not confirm NF-1 or any other genetic cause of pheochromocytoma. The patient had total thyroidectomy 3 years after initial presentation, for bilateral thyroid nodules with FNA having shown oncocytic follicular neoplasia. Calcitonin levels were negative. Histology only found oncocytic hyperplasia with no proof of malignancy. No tumor recurrence was found at follow-up (7 years). Composite pheochromocytomas are rare tumors consisting of pheochromocytoma and neurogenic tumors (most frequently ganglioneuroma but also ganglioneuroblastoma, neuroblastoma, or peripheral nerve sheath tumor), with only a few series of cases cited in literature. There is uncertainty concerning natural history of these tumors, which often seem to be associated with NF-1. Only a few cases of composite pheochromocytoma with neuroblastoma have been published, and prognosis seems to be related to this latter component. MYC-N gene amplification (negative in our patient) has been found to predict aggressive behavior.