Endocrine Abstracts

Introduction: Pheochromocytoma is a tumour of chromaffin cells of the sympathetic nervous system and its clinical symptoms are associated with excessive production and release of catecholamines.

Case report: We report a rare case of non-functioning malignant adrenal oncocytic pheochromocytoma incidentally found during yearly repeated ultrasound abdomen examination in a 78-year-old man with history of cardiovascular diseases: aortal abdominal aneurysm, ischemic heart disease and some years ago an episode of hypertension. The patient confirmed a polycyclic high density large left adrenal mass. The preoperative problem in the differential diagnosis of this case was to determine its origin (adrenal or renal). The lack of did not have clinical manifestations of pheochromocytoma. Computed tomography study typical symptoms and signs and the low level of catecholamine metabolites (Metanephrine 53.78 ug/24 h: No. 52-341, Normetanephrine 200.14 ug/24 h: No. 88–440, VMA 11.6 umol/24 h: No. 9–36) preoperatively further eliminated some clues for differential diagnosis. The tumor measured 80×60×60 mm was subsequently excised. It was considered to be a malignant lesion because of the size, extracapsular extension and focal necrosis. Histological examination revealed an oncocytic pheochromocytoma. It consisted of large polygonal tumor cells containing eosinophilic granular cytoplasm. The latter were immunohistochemically positive for chromogranin, vimentin and s-100 protein. During three years follow up patient was in general good condition - free of disease. Three years after adreanlectomy he had a relapse and then died because of dissemination.

Conclusion: There are only few papers on cases of adrenal oncocytic pheochromocytoma.

Because of unusual histology and rarity of this type of tumor, we report a case of adrenal oncocytic pheochromocytoma including its’ visual, histologic and immunohistochemical features.

The presented case appears to be the first adrenal oncocytic malignant and non-functioning pheochromocytoma. It confirms the complexity of biology and difficulties in diagnosing this type of neoplasm.

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 research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.