Endocrine Abstracts

Composite pheochromocytomas (CP) are rare and constitute 3% of pheochromocytomas. So far, less than 100 cases were described in the literature. We present a case of 60 years old man. He was admitted to ER department due to severe bone pain around chest, ribs and vertebra. CT scan showed expansive, 100x87 mm, non-homogenic left adrenal gland tumour as well as metastatic bone lesions. The 24-hour urinary fractionated metanephrines were significantly elevated - 86195 ug/24h (normal range:88,0-440,0), 10214,1ug/24h (normal range:0,0-220,0) and 3302,4 ug/24h (52,0-341,0) for urinary fractionated normetanephrine, 3-methoxytyramine, and metanephrine, respectively. Patient presented no typical symptoms suggestive of pheochromocytoma like hypertension or tachycardia. Tc-99m somatostatin analogues scintigraphy revealed pathological tracer uptake in the left adrenal gland and bones. Patient underwent left adrenalectomy preceding by pharmacological pre-treatment with alpha-receptor blockers. Histopathology showed composite pheochromocytoma with ganglioneuroma component (Ki67 15%, PASS 9). Due to results of MIBG scan, which showed massive bone metastases, patient was qualified for stem cells preservation followed by radioisotope therapy (I-131 MIBG). Initial genetic testing (MAX, RET, SDHB/SDHD, VHL, MEN1) didn’t confirm genetic background, further genetic testing results (TMEM, EPAS FH, SDHA, SDHAF2) are expected. In conclusion, metastatic potential of pheochromocytoma in this case should be suspected based on large tumour dimension (> 6 cm), secretion of norepinephrine and dopamine, as well as distinct histological features ( Ki67>3%, PASS>6). Due to its rarity, it is not well known if non-pheochromocytoma component in CP poses any prognostic factor, which needs further investigations.