Endoscopic Ultrasound in Endocrinology: Imaging of the Adrenals and the Endocrine Pancreas

Abstract

Endoscopic ultrasound (EUS) imaging of adrenal glands and its application to diagnostic procedures of adrenal diseases has been reported since 1998. It can be considered a relevant advantage in the field of adrenal diseases. Indeed, EUS allows the detection of adrenal lesions (even very small ones) and their characterization, the assessment of malignancy criteria, the early detection of neoplastic recurrences, the preoperative identification of morphologically healthy parts of the glands, the differentiation of extra-adrenal from adrenal tumors, and of the pathological entities associated with adrenal insufficiency, and the fine-needle aspiration biopsy (EUS-FNA) of suspicious lesions. At the same time, its clinical relevance depends on the experience of the endosonographer. Moreover, EUS is also by far the best and most sensitive imaging technique to detect and assess the follow-up of pancreatic manifestation of MEN1 disease. It furthermore enables the preoperatively localization of insulinomas and critical structures in their neighborhood, and may be relevant in planning surgical strategy. A positive EUS in a case of insulinoma furthermore confirms the endocrine diagnosis, especially considering the differential diagnosis of hypoglycemia factitia by oral antidiabetics. It can be supplemented by EUS-FNA. Again, it has to be considered that EUS may reveal false positive and false negative results, and the quality of the findings largely depends on the endosonographer's skills and experience. The most important technical details together with the advantages and limitations of EUS, and the pathognomonic characteristic of benign and malignant disorders of the adrenals and pancreas are presented here.

The future: diagnostic and imaging advances in MEN1 therapeutic approaches and management strategies

“…EUS was capable to detect adrenal enlargement in 21/21(100%) cases, whereas CT failed in 7 cases. Kann confirmed these results (Kann 2016). The authors prefer EUS and MRI for adrenal imaging, which is already covered by imaging for dpNEN.…”

Sonografie und Endosonografie der Nebennieren

“…In the case of hypoechoic enlargement of the adrenal gland without a delineated mass lesion, diffuse malignant infiltration by a carcinoma or lymphoma must be considered as a differential diagnosis to hyperplasia. In the case of patients with multiple endocrine neoplasia (MEN) type 2a and von Hippel-Lindau disease without pheochromocytoma, endoscopic ultrasound shows broadening of the central echo in terms of medullary hyperplasia [13,15]. Micronodular cortical hyperplasia with nodular enlargement in the area of the wings without significant differences in echogenicity with respect to the rest of the parenchyma shown with endoscopic ultrasound as a morphological correlate of idiopathic hyperaldosteronism is Abb.…”

“…Eine deutliche Verschmälerung der Nebennieren ist das morphologische Korrelat des autoimmunen Morbus Addison. Verkalkungen können auf eine posttuberkulöse oder hämorrhagische Genese der Nebenniereninsuffizienz hinweisen [5,13,15].…”

“…Significant narrowing of the adrenal glands is the morphological correlate of autoimmune Addision's disease. Calcifications can indicate a post-tuberculotic or hemorrhagic origin of the hypoadrenalism [5,13,15].…”

Laparoscopic surgery for pancreatic insulinomas: an update

“…33 As is also the case in pancreatic adenocarcinoma, EUS yields important information regarding the lesion's proximity to major anatomic structures such as the major pancreatic duct and splenic vessels. 36 EUS has been reported to be most accurate in tumors occurring in the head of the pancreas, while tumors at the tail are hardest to localize. 37,38 Added benefits of EUS include the possibility for fine needle aspiration and cytological examination in circumstances where the diagnosis is in doubt and preoperative tattooing of the lesion/lesions to further assist in intraoperative identification ( Figure 2).…”