Michael E. Flisak

Inflammatory pseudotumor of the liver: Appearance on MRI

Inflammatory pseudotumor of the liver is a rare entity; fewer than 50 cases have been reported in the world literature. Its appearance on both computerized tomography (CT) and ultrasound have been previously described. To our knowledge, this is the first report of its appearance on magnetic resonance imaging (MRI). The lesion demonstrated increased signal intensity on T-1 and T-2 spin-echo and inversion recovery (STIR) sequences in relationship to normal liver. The signal characteristics, however, were nonspecific and diagnosis required biopsy confirmation. There was spontaneous resolution with conservative management, and this was documented on follow-up CT and MRI.

Selective intra-arterial methylene blue injection: A novel method of localizing gastrinoma

A 40-year-old woman had persistent Zollinger-Ellison syndrome despite excision of a 4-cm duodenal gastrinoma. Localizing studies including ultrasonography, computed tomography, magnetic resonance imaging, duodenal endoscopy, endoscopic ultrasonography, and intraoperative endoscopic transillumination of the duodenum failed to detect a tumor. Selective intra-arterial methylene blue injection was used to identify a 6-mm gastrinoma in the duodenum, which was locally excised. Postoperatively, the patient had a negative secretin provocative test result. This novel method uses selective arterial secretin injection with hepatic venous gastrin sampling to identify the vessel feeding the gastrinoma. An angiographic catheter is then positioned in this artery. At laparotomy, methylene blue is injected through this catheter to selectively stain the gastrinoma, facilitating its identification. Selective intra-arterial methylene blue injection can enhance intraoperative detection of small gastrinomas and may improve the rate of curative resection in the Zollinger-Ellison syndrome. Further evaluation of this novel localizing technique is warranted.