Endoscopic ultrasonography is recently known as a valuable procedure in detection and localization of adrenal lesions. Nevertheless, tumor classification by endosonomorphological criteria is still difficult.

Objective: After primary hyperaldosteronism (PA) is hormonally documented, the most important step is to differentiate between a disease that can be surgically cured (aldosterone-producing adenoma – APA) and other entities of PA, especially bilateral adrenal hyperplasia (BAH). Classical imaging of adrenal glands (computed tomography, magnetic resonance, adrenal scintigraphy) may miss small unilateral or bilateral lesions or give ambiguous results, though it is necessary to make the distinction by adrenal venous sampling (AVS). We evaluated retrospectively the value of endosonography in detecting adrenal tumors or adrenal hyperplasia.

Endosonography enables imaging of the adrenal glands, the mediastinum, and the epigastric retroperitoneal area. In this study, the diagnostic power of endosonography regarding the detection and localization of pheochromocytomas and the differentiation between benign and malignant lesions and their metastases and recurrences was investigated. Endosonography was performed using a Pentax FG 32 UA endosonoscope with a longitudinal 7.5-MHz sector array from the esophagus, stomach, and duodenum. A total of 22 pheochromocytomas in 11 patients were studied. All these tumors, recurrences, and metastases were histologically proven except in one single patient where pheochromocytoma had been diagnosed histologically in the past, and actual findings were obvious local recurrence and four metastases. Malignant pheochromocytoma (n=10) tended to be larger at the time of examination than benign pheochromocytoma (n=12; P=0.069). No significant differences between benign and malignant pheochromocytomas regarding echogeneity and echostructure could be detected. However, hyperechoic echogeneity was seen only in benign lesions, which, however, had variable echogeneity. If confirmed by future observations, hyperechoic echogeneity may be considered to be suggestive of a benign nature. In several cases, endosonography detected small lesions that had been missed by routine diagnostic procedures and yielded helpful information for planning surgical strategy. In conclusion, endosonography is considered to be useful in early detection of pheochromocytomas, and in malignant disease of recurrence and metastases.

OBJECTIVEEndosonography enables localization and characterization of gastroenteropancreatic neuroendocrine tumors. We have studied the problem of misleading abnormalities of pancreatic morphology as obtained by endosonographic imaging.DESIGN AND METHODSA total of 438 endosonographies performed for known or suspected diseases of the adrenal glands and/or the pancreas and/or suspected metastases in the neighboring tissues were analyzed.RESULTSIn the pancreas, nine benign insulinomas, four non-metastatic islet cell carcinomas, and multiple benign neuroendocrine tumors in one patient with multiple-endocrine neoplasia-1 (MEN-1) disease were detected and correctly localized as proven by postoperative histology. In three further patients with genetic diagnosis of MEN-1, asymptomatic tumors were detected and are under observation. However, we also found an 8 x 4 mm hypoechoic tumor in the cauda pancreatis of a patient with severe factitial hypoglycemia (glimepiride). In another patient suffering from severe hypoglycemia, a hypoechoic area of 24 x 10 mm in the processus uncinatus/caput pancreatis was found. Although organic hyperinsulinism was excluded, this patient underwent surgery because of suspected pancreatic carcinoma. There was normal pancreatic tissue in the abnormal region, which was also localized by intraoperative sonography. In a third patient with an adrenal carcinoma, a 6 x 3 mm hypoechoic nodule in the cauda pancreatis did not change its morphology over an observation period of 13 months, its clinical relevance is completely unclear.CONCLUSIONSPancreatic nodules of unknown dignity were detected in nearly 1% of our patients and must be considered to be a diagnostic problem. These experiences clearly show, on the one hand, that pancreatic endosonography is a very useful diagnostic support in the management of endocrine tumor patients. However, on the other hand, endosonography of endocrine organs is not a substitute for careful endocrinological examination and testing and must be considered in the context of endocrinological findings.