intestinal perineurioma
Defintion: subtype of benign peripheral nerve sheath tumor.
Synopsis
Age: median age, 51 years; range, 35-72 years
intramucosal perineuriomas (small sessile polyps)
submucosal masses
uniform bland spindle cells having ovoid to elongated nuclei and pale indistinct cytoplasm
no cytologic atypia, pleomorphism, or mitotic activity
fine collagenous stroma
irregular borders with the adjacent lamina propria and entrapped colonic crypts
+/- hyperplastic changes in the adjacent or entrapped epithelium.
collagenous stroma or myxoid stroma
spindle cells with tapered nuclei and elongated bipolar cytoplasmic processes
Immunochemistry
positive for epithelial membrane antigen (EMA+)
CD34+
+/- claudin-1 and 2 of 10 expressed
negative for
- S-100 protein
- glial fibrillary acidic protein
- neurofilament protein
- smooth muscle actin
- desmin
- caldesmon
- KIT
- pan-keratin
Ultrastructure
spindle cells with long bipolar cytoplasmic processes
prominent pinocytotic vesicles
cells surrounded by discontinuous basal lamina
See also
benign peripheral nerve sheath tumors
digestive fusiform cell tumors (spindle cell tumors)
References
Hornick JL, Fletcher CD. Intestinal perineuriomas: clinicopathologic definition of a new anatomic subset in a series of 10 cases. Am J Surg Pathol. 2005 Jul;29(7):859-65. PMID: #15958849#