Malignant peripheral nerve sheath tumour metastasising to the parotid gland

Parotid Neurogenic Tumors: MPNST Sarcoma to Schwannoma-Review of Literature and Guidelines in Management

Objective

To delineate a distinct clinical, pathological, cytoimmunohistochemical distinguishing features of extracranial parotid neurogenic tumors. Pleomorphic adenoma, the most common parotid neoplasm by itself can mimic a neurogenic tumor, i.e., schwannoma. We have reported such rare entity in earlier publications. This is a systematic review with a case discussion of the third only documented malignant peripheral nerve sheath tumor (MPNST) arising in the parotid in a noncontiguous fashion. We review the management, diagnostic immunohistochemistry of this low-grade sarcoma, which has not been documented thus far.

Purpose

Significant diagnostic and management pitfalls may occur even with fine-needle aspiration or biopsy, as they will not be ideal in diagnosis of parotid neurogenic neoplasms preoperatively. Ultrasound as well as magnetic resonance imaging may not offer a specific facial nerve course in association to the neoplastic lesion. Majority of the neurogenic tumors can be misdiagnosed and hence, improperly managed leading to facial nerve injury and tumor morbidity. Due to the lack of ideal diagnostic modality and morbidity of facial nerve injury, a thorough review of differential diagnosis inclusive of neurogenic tumors of the parotid is to be considered in indications of surgical approaches. We retrospectively review successful resection with preservation of facial nerve function in our parotid neurogenic tumors.

Conclusion

The objective of this paper is to review the guidelines and treatment planning of parotid neurogenic tumors.

Immunoprofiles in malignant peripheral nerve sheath tumor: three case reports and literature review

Because there are no standardized radiologic and histologic criteria, the differential diagnosis of malignant peripheral nerve sheath tumors (MPNSTs) from other spindle cell neoplasms poses great challenges for pathologists. Because early diagnosis of MPNSTs arising from benign peripheral nerve sheath tumors (BPNSTs) means a better prognosis, many immunohistochemical and molecular studies have recently emerged. Nevertheless, no gold standard diagnostic criterion is to be found in the literature. For example, S-100 protein is widely used in the diagnosis of MPNST. Other promising ancillary markers are p53 and Ki-67; however, the staining patterns and possible mechanisms of these markers are seldom mentioned in the literature. These evoke our interest. Only six cases diagnosed as MPNST were retrieved from the archives of the Department of Pathology, Kaohsiung Medical University Chung-Ho Memorial Hospital between 1988 and September 2005. Clinical files were available for three of them, and we found nuances in the immunohistochemistry from these previous reports. Here, we present these rare sarcomas and review the literature.

Multidisciplinary management of head and neck sarcomas

BACKGROUND

Head and neck sarcomas are extremely rare. This article reviews the management and outcomes in a multidisciplinary clinic.

METHODS

The records of 41 male and 19 female patients (mean age, 50 years) were reviewed. Forty percent underwent surgical resection only, 35% underwent surgery and adjuvant therapy, and 25% underwent radiotherapy and/or chemotherapy without surgery. Seventy-one percent had complete histologic clearance.

RESULTS

The mean follow-up was 3 years and 10 months, with an overall 5-year survival rate of 60%. Completeness of surgical excision was highly significant in determining 5-year local control (p < .025), and the addition of adjuvant radiotherapy had a major effect on local control, but only if complete surgical clearance had been achieved (p < .025). As expected, patients with more aggressive tumors had a significantly poorer overall prognosis, and achieving local control led to an enhanced 5-year survival (p < .025).

CONCLUSION

These tumors are best managed in multidisciplinary clinics, and the mainstay of treatment is wide local excision and planned postoperative adjuvant radiotherapy.