Endocrine Abstracts

Paraganglioneuromas producing predominantly dopamine are very rare. Such tumours are potentially malignant and often tend to have atypical clinical presentation. Majority of the patients are normotensive and tumours are detected incidentally on imaging studies. We report a case of dopamine secreting – malignant paraganglioneuroma with spinal metastasis. A 65-year-old man was referred to the endocrinology clinic after an incidental finding of large right para-adrenal mass on ultrasound. He denied any history of palpitations, headaches, and dizziness and was normotensive. Ten years previously he had an excision of right-sided neck mass, which was reported to be a benign paraganglioneuroma. Endocrine investigations showed normal levels of serum aldosterone and renin. 24-hour urine 5HIAA and cortisol, adrenaline and noradrenaline were within the reference range and dopamine measured 49.6 (0.22–2.86 μmol/24 hr). Neurogut peptides were negative. CT scan abdomen displayed a 12 cm lesion superior to the right kidney in keeping with an adrenal mass without any features of malignancy. The patient underwent excision of the tumour and histology suggested a benign paraganglioneuroma.

On subsequent endocrine follow up the patient had persistently high levels of urinary dopamine. A I-123 MIBG scan performed to detect any remnant paraganglioneuromic tissue demonstrated a pathologically increased uptake in the neck, right half of the abdomen and the whole length of spine. These findings were confirmed by a 24hr SPECT CT neck and abdomen. An MRI demonstrated multiple metastases predominantly along the thoracolumbar spine and narrowing of the spinal canal at L2. The patient received a short course of radiotherapy to the lower thoracolumbar spine and is currently under our follow up. The aforementioned case reinforces a high index of clinical suspicion about the malignant potential of dopamine secreting paraganglioneuroma.