Features of CT and EUS in mesenteric plexiform neurofibroma with Neurofibromatosis type I: A case report

Abstract

Plexiform neurofibroma(PNF) is a rare benign tumor of the peripheral nerve, belonging to a subtype of neurofibroma. PNF is common in the head, neck and trunk. It is uncommonly observed in the mesentery. We report a case of mesenteric PNF in a 64-year-old man history of neurofibromatosis type I(NF1), which caused abdomen pain. In addition, the computer tomography(CT) and endoscopic ultrasonography(EUS) manifestations of mesenteric PNF were analyzed. The imaging appearance of a mesenteric plexiform neurofibroma is that many low-density (CT) /mixed echo (EUS) soft tissue masses surrounding the superior mesenteric artery, but not surrounding the superior mesenteric vein. Our case adds to the limited literature regarding NF1 presenting with mesenteric PNF. The computer tomography and endoscopic ultrasonography may facilitate confirma diagnosis of mesenteric PNF.

Keywords: Computer tomography; Endoscopic ultrasonography; Mesentery; Neurofibromatosis type I; Plexiform neurofibroma.

Fig. 1

A 64-year- old man with mesenteric plexiform neurofibromas. Abdominal CT (A-C), (F-I):Axial planes; (D):coronal planes; (E):Sagittal planes showed multiple soft tissue masses (long white arrow, A-C) in the intestinal mesentery, with clear boundaries and no obvious signs of infiltration and metastasis. Their density was homogeneous and lower than muscle tissue at the same level. Scattered fat density was found between these hypodense masses (short white arrow, A). There was no obvious enhancement with these masses in the arterial phase (B) and venous phase (C) after intravenous injection of iodine contrast agent. These masses wraped the mesenteric vessels, but the blood vessel wall was not significantly infiltrated (short white arrow, D-E). In addition, there were multiple subcutaneous nodular in the abdomen (curved white arrows, F-G), with soft tissue density, clear boundaries and no obvious enhancement in the arterial phases (curved white arrows, H) and venous phases (curved white arrows, I) after enhancement.

Fig. 2

Volume rendering technique (VRT). Mesenteric vessels (white arrow, 2A) surrounded by intra-abdominal masses (green lumps, 2A & B).

Fig. 3

Endoscopic ultrasonography(EUS) findings. Linear 7.5 MHz EUS for stomach and duodenum revealed that multiple mixed echogenic nodules were distributed on the mesenteric membrane, resembling grape clusters. The lesion only grows along the superior mesenteric artery and does not involve the adjacent superior mesenteric vein (A).

Fig. 4

Macroscopic appearance of the laparoscopic biopsy specimen. Laparoscopic biopsy showed a significant thickening of the mesentery, A large number of small, smooth, grayish-white and hard nodular structures are found in the mesentery of the small intestine(A). The tumor surrounds the mesenteric blood vessels and a small amount of fatty tissue (B).

Fig. 5

Histopathological fndings of the tumor. Histopathological examination shows spindle cell hyperplasia in the mesenteric nodules. Hematoxylin and eosin staining at high magnifcation (200 ×) (A) show a low degree of cellular atypia, and absence of nuclear division. S-100(B) and fibroblasts CD34(C) immunostaining reveals positivity.