CT AND MRI IMAGING CHARACTERISTICS OF ADRENAL PHEOCHROMOCYTOMA

Abstract

Objective: (1) To describe the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of adrenal pheochromocytoma; (2) To evaluate the role of CT and MRI in the diagnosis of pheochromocytoma. Methods: A cross-sectional descriptive study was conducted on 70 patients diagnosed at Bach Mai Hospital. Age, sex and hypertension were analyzed tumor location, size and imaging features on CT (cystic degeneration, necrosis, calcification, contrast washout) and MRI (cystic degeneration, T2-weighted signal, lightbulb sign, diffusion restriction on ADC map). Results: Mean age was 48.1 ± 15.7 years (range 11–78); female/male ratio was 1:1. Hypertension was present in 72.9% of patients (n=70). Tumors were more common on the right side (55.4%). Among 74 tumors, with a mean size of 50.4 ± 24.0mm; 82.4% of tumors were larger than 30mm. CT was performed in 63 tumors (85.1%) and MRI in 23 tumors (31.1%). On CT, cystic degeneration, necrosis and calcification were observed in 49.2%, 33.3% and 20.6% of cases, respectively. On MRI, T2 hyperintensity was present in 91.3%, diffusion restriction in 82.6%, while the classic lightbulb sign was seen in only 39.1%. Combined sensitivity reached 55.6-77.8% on CT and 100% on MRI (T2 hyperintensity and/or diffusion restriction). Conclusions: Pheochromocytoma shows characteristic imaging features on CT and MRI, with T2 hyperintensity and diffusion restriction being the most frequently observed MRI signs. Larger tumors are associated with more pronounced degenerative changes (necrosis, calcification, cystic degeneration) on CT. Keywords: Pheochromocytoma, adrenal medulla tumor, computed tomography, magnetic resonance imaging, diagnostic imaging.