(Radiology Review) Researchers recently evaluated the prevalence of incidental and symptomatic pheochromocytomas and their CT imaging characteristics. Results of their study were published in the American Journal of Roentgenology (September 2005, Vol. 185:3, pp. 684-688).
Dr. Gaspar A. Motta-Ramirez and colleagues at the Cleveland Clinic Foundation in Ohio conducted a retrospective study of 335 patients who underwent adrenalectomy and demonstrated 71 pheochromocytomas. Thirty-three patients had CT examinations. The researchers found no CT parameters that enabled differentiation of incidental and symptomatic pheochromocytomas.
The authors defined patients as symptomatic or incidental depending of their clinical presentation. Differences in "patient age, adrenal mass volume and maximal diameter based on CT dimensions, attenuation on unenhanced CT, attenuation on enhanced CT during the portal phase, the presence of calcifications, low attenuation or cystic changes, biochemical activity, and hypertension," were reviewed.
CT was performed using a Somatom Plus 4, Plus 4 Volume Zoom, or Sensation 16 scanner (Siemens Medical Solutions, Malvern, PA) with a 2.5-, 3- or 5- mm collimation, 2.5- to 3-mm slice interval, and 2.5- or 5-mm slice thickness. Patients received 150 mL of IV iodinated contrast material (300 mg I/mL Ultravist, Berlex Imaging, Wayne, NJ) at a rate of 2-4 mL/sec.
The researchers found that 57.6% of adrenal pheochromocytomas were incidental and 42.2% were symptomatic. All symptomatic patients had hypertension compared with 52.6% of incidentally diagnosed pheochromocytomas showing calcification. They found no statistically significant difference in patient age, volume of the mass, diameter of the mass, or attenuation on enhanced or unenhanced CT. "No attenuation value of any pheochromocytoma was less than 10 H on unenhanced CT," they wrote.
"In our study population, 57.6% of the pheochromocytomas were incidental, more than in most reported series. A history of hypertension was more frequent in the symptomatic group; but no radiologic parameters that allow differentiation of incidental and symptomatic pheochromocytomas were found," the researchers concluded.
"Comparison of CT Findings in Symptomatic and Incidentally Discovered Pheochromocytomas"
Gaspar A. Motta-Ramirez et al
Department of Radiology, Cleveland Clinic Foundation
9500 Euclid Ave., Cleveland, OH 44195, USA
AJR 2005; 185:684-688
By Radiology Review
September 16, 2005
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