Endocrine Abstracts

Introduction: Pheochromocytomas are uncommon neuroendocrine tumors arising from chromaffin cells of the adrenal medulla. The aim of our study was to assess imaging characteristics of pheochromocytomas.

Methods: The study was a retrospective analysis of 23 patients with pheochromocytomas. All participants had a computed tomography scan (CT). Several clinical and radiologic features were statistically analysed.

Results: The Mean age was 47.04±12.31 years and the sex-ratio (M/F) was 0.39. All pheochromocytomas were unilateral. Malignancy was proven in five cases. The mean tumor size was 54.17±29.47 mm (Extremes: 20–130 mm). Out of 23 participants, 19 patients had a tumour larger than 30 mm. There was no significant correlation between tumour size and urinary metanephrines (P=0.8). However, a significant correlation between tumor size and the degree of malignancy (r=0.54, P=0.03) was identified. The majority of pheochromocytomas (n=22) had attenuation values greater than 10 Hounsfield units with a heterogeneous enhancement in contrast-enhanced CT. Smaller lesions were typically homogeneous (3/4) whereas larger tumours were more heterogeneous (16/19). Calcifications, necrosis and cystic components were present in 3, 8 and 2 cases, respectively.

Conclusion: Computed tomography scan has been established as the main tool to identify pheochromocytoma, with an overall sensitivity of 89%. The typical appearance of a pheochromocytoma in computed tomography is a mass with a large size, high density greater than 10 Hounsfield units, avid contrast enhancement due to a rich capillary network, and delayed washout. Cystic changes, necrosis, and internal calcifications are commonly described in the literature.