palisaded encapsulated (solitary circumscribed) neuromas (pens) are relatively common intraoral neurogenic tumors, which occur most frequently on the hard palate. herein, we describe the clinicopathological characteristics of a palisaded encapsulated neuroma of the tongue. this tumor was an exophytic sessile mass measuring 0.3× 0.4 cm with rubbery consistency on the anterior one-third of the do...

malignant peripheral nerve-sheath tumor (mpnst) is a high-grade malignant tumor of ecto-mesenchymal origin comprising approximately 10% of soft-tissue sarcomas. they tend to occur associated with neurofibromatosis or sporadically. here we report a mpnst at an extremely rare location and behavior causing disappearance of the entire kidney. patient evaluation included clinical, biochemical and ra...

background and objective: approximately 45% of benign peripheral nerve sheath tumors (pnst) occur in head and neck regions. malignant peripheral nerve sheath tumors (mpnst) are less common and only 8-15% of these tumors occur in head and neck region. in this study, we aimed at evaluating the demographic characteristics, pathologic findings, locations, main clinical presentations and family hist...

Tumors of peripheral nerve are largely neuroectodermal in nature and derived from 2 elements of nerve, Schwann or perineurial cells. In contrast, mesenchymal tumors affecting peripheral nerve are rare and are derived mainly from epineurial connective tissue. The spectrum of the latter is broad and includes lipoma, vascular neoplasms, hematopoietic tumors, and even meningioma. Of malignant perip...

Schwannomas are peripheral nerve sheath benign tumors which arise from the schwann cells. These neoplasms most frequently seen in 3 to 6 decade of life and affecting limbs followed by head neck region. Oropharyngeal vallecular involvement schwannomas is extremely rarely reported previous literature. We report a case 25 year old male with lesion vallecula was subsequently diagnosed as on histopa...

By using the D2-40 antibody, we have observed podoplanin expression in Schwann cells and perineurial cells. Podoplanin expression has not been well characterized in peripheral nerve sheath tumors. Because neoplasms of neural crest lineage, including peripheral nerve sheath and melanocytic neoplasms, may share histologic and immunohistochemical characteristics, we evaluated podoplanin and S-100 ...

Mel-CAM (previously MUC18) is an integral membrane glycoprotein involved in heterophilic intercellular adhesions. Mel-CAM is expressed specifically in certain normal mesenchymal tissues, including smooth muscle, endothelium, and Schwann cells. As a member of the immunoglobulin supergene family of cell adhesion molecules (CAMs), Mel-CAM may play a pivotal role in the normal differentiation and f...

Malignant peripheral nerve sheath tumors (MPNSTs) are rare neoplasms with an incidence of about 0.001% in general population. They usually arise from components of nerve sheath such as perineural fibroblasts or Schwann cells, and are often considered as a form of soft tissue sarcoma.1 Most of these MPNSTs are located in the buttocks, thighs, brachial plexus, and paraspinal region, and are rarel...

Schwannomas, also known as neurilemmomas, are generally benign peripheral nerve sheath tumors developing from Schwann cells. Peripheral nerve sheath tumors account for less than 8% of soft tissue neoplasms. Schwannomas are characterized by a slow-growing and non-infiltrating pattern. We report a 21-year-old, right-handed male, with a mass at his right elbow anterolateral region, that was slowly...