ADRENAL PHEOCHROMOCYTOMAS - A BROAD-SPECTRUM OF SONOGRAPHIC PRESENTATION

Sonographic findings in 19 patients with proved adrenal pheochromocyto mas observed over a 10 year period were evaluated retrospectively. Adr enal tumors were analyzed by number, size, echogenicity, internal echo genicity, and biologic behavior. There were 16 benign and 3 malignant pheochromocytomas, all of which were well marginated or encapsulated a nd ranged from 1.4 to 11 cm in greatest diameter (mean, 4.8 +/- 2.2 cm ). A broad spectrum of sonographic appearances has been noted, includi ng purely solid tumors (68%), complex masses (16%), and cystic lesions (16%). Compared with renal parenchyma as a reference tissue, 10 (77%) of 13 solid pheochromocytomas were isoechoic or hypoechoic, whereas t hree (23%) were hyperechoic. Six (46%) of the solid tumors were homoge neously echogenic, and seven (54%) were heterogeneous. Ultrasonic disc rimination between benign and malignant pheochromocytoma on the basis of acoustic features alone has proved impossible. Abdominal sonography , however, provided evidence of malignancy in all three patients with malignant tumors by disclosing regional or distant metastases. In conc lusion, rather than showing a specific uniform ultrasonographic appear ance, pheochromocytoma is associated with a broad spectrum of possible sonographic presentations.