Contrast harmonic EUS for the prediction of pancreatic neuroendocrine tumor aggressiveness (with videos).

BACKGROUND AND AIMS: Contrast harmonic EUS (CH-EUS) has the ability to depict tumor microvasculature. Decreased microvascular density has been identified as a factor associated with tumor aggressiveness. We aimed to study the accuracy of CH-EUS for the prediction of pancreatic neuroendocrine tumor (PNET) aggressiveness. METHODS: Between June 2009 and March 2015, all consecutive patients with histology-proven PNETs and CH-EUS examination were included. Nine endosonographers blindly analyzed all videos. CH-EUS tumor aggressiveness was defined as a heterogeneous enhancement at the early arterial phase. The final diagnosis of tumor aggressiveness was defined as follows: G3 tumors, morphologic and/or histologic findings of metastatic disease in G1/G2 tumors. Diagnostic values were calculated. Intratumoral microvascular density and fibrosis were assessed on pathologic specimens. RESULTS: Eighty-one tumors were included, of which 26 were aggressive (32.1%). In CH-EUS 35 tumors (43.2%) had a heterogeneous enhancement. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CH-EUS for the diagnosis of tumor aggressiveness were 86%, 96%, 82%, 71%, and 98%, respectively. The interobserver agreement among the 9 endosonographers was good (k = .66). The intraobserver agreement was excellent for the junior (κ = .83) and senior (κ = .82) endosonographers. Heterogeneous tumors at CH-EUS corresponded to fewer vascular and more fibrotic tumors (P < .01). CONCLUSIONS: CH-EUS is accurate in the prediction of PNET aggressiveness and could be a decision-making element in their management.

Increased growth rate of vestibular schwannoma after resection of contralateral tumor in neurofibromatosis type 2.

Surgical management of bilateral vestibular schwannomas (VS) in neurofibromatosis type 2 (NF2) is often difficult, especially when both tumors threaten the brainstem. When the largest tumor has been removed, the management of the contralateral VS may become puzzling. To give new insights into the growth pattern of these tumors and to determine the best time point for treatment (surgery or medical treatment), we studied radiological growth in 11 VS (11 patients with NF2) over a long period (mean duration, 7.6 years), before and after removal of the contralateral tumor while both were threatening the brainstem. We used a quantitative approach of the radiological velocity of diametric expansion (VDE) on consecutive magnetic resonance images. Before first surgery, growth patterns of both tumors were similar in 9 of 11 cases. After the first surgery, VDE of the remaining VS was significantly elevated, compared with the preoperative period (2.5 ± 2.2 vs 4.4 ± 3.4 mm/year; P = .01, by Wilcoxon test). Decrease in hearing function was associated with increased postoperative growth in 3 cases. Growth pattern of coexisting intracranial meningiomas was not modified by VS surgery on the first side. In conclusion, removal of a large VS in a patient with NF2 might induce an increase in the growth rate of the contralateral medium or large VS. This possibility should be integrated in NF2 patient management to adequately treat the second VS.