Endocrine Abstracts

Pheochromocytomas, tumors derived from adrenal medulla, are characterized by a polymorphic clinical picture dominated by paroxysmal hypertension. Between the clinical, laboratory and pathology data, discordances are frequently seen.

Patients and Methods: Thirty five cases of pheochromocytoma and paraganglioma (10 men) with adrenal tumors and hypertension were confirmed with pheochromocytoma. They were aged 53.68±12.75 years (36–75), while the tumor diameter ranged from 1.5 to 13 cm. Five cases were oligosymptomatic, with only one or two crises in life suggesting catecholamine excess. The evaluation was done for plasma metanephrines and normetanephrines as well as chromogranin A (CGA) with Elisa commercial assays. Immunohistochemistry was performed on removed tumor tissue on paraffin sections by avidin biotin complex method using antibodies against CGA, neuron specific enolase (NSE), synapthophysin (SYN), protein S100, succinate dehydrogenase, as well as Ki67 index as marker of tumor proliferation. The staining intensity was marked from 0 to 3, considering the number of stained cells.

Results: The initial evaluation confirmed excess of plasma metanephrines (MN) (736.11±886.51 pg/ml), normetanephrines (NMN) (2423.26±1907.6 pg/ml) and CGA (790.44±697.85 ng/ml). Immunostaining for CGA was moderate / intense positive in 30/35 cases, in 3 cases the plasma CGA values being in normal range. Better pathology markers were NSE and SYN, while S100 protein was nonspecificaly high even in oligosymptomatic tumors. Olygosymptomatic patients were with similar plasma values as compared with pheochromocytoma with frequent crises, but SYN and NSE staining was weaker. Ki67 index, around 2–4%, was not related to plasma or pathology data.

Conclusions: From our data, there is no direct correlation between classical neuroendocrine plasma and pathology markers; still, low expression of NSE and SYN might reflect a lower metabolism rate in oligosymptomatic tumors.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.