Pancreatic neurofibroma
Pancreatic neurofibromas are rare nonepithelial neoplasms of the pancreas. They are similar to neurofibromas found elsewhere in the body, and are associated with neurofibromatosis type I.
Clinical presentation
If they do cause symptoms, it will typically be those related to regional mass effect.
Pathology
Neurofibromas arise from the elements of peripheral nerves, including Schwann cells.
Histologically, benign spindle cells are present in a myxoid fibrillary matrix. Neurofibromas express S100, but no P53 and limited Ki-67.
Radiographic features
CT
- well-circumscribed
- hypoattenuating
- mildly enhancing
MRI
- T1: hypointense
- T2: hyperintense
Classic appearance is a "target" with a T2 hypointense core surrounded by a T2 hyperintense ring, similar to neurofibromas elsewhere in the body. The myxoid component of the tumor results in the T2 hyperintensity.
- cystic change, calcification, and hemorrhage may be present
US
- well-defined
- hypoechoic with posterior through-transmission
Treatment and prognosis
Malignant transformation has been estimated to occur in 7-13% of neurofibromas . Because of its location, neurofibromas in the pancreas may be treated conservatively.
Differential diagnosis
- pancreatic neuroendocrine tumor
- more common overall
- may have a syndromic presentation
- pancreatic Schwannoma:
- associated with neurofibromatosis type 2
- will have a different histological appearance
- a mucinous lesion of the pancreas with features suspicious for malignancy
- will have characteristic findings on EUS biochemistry and cytology
Siehe auch:
Assoziationen und Differentialdiagnosen zu Neurofibrom des Pankreas: