A Case of Malignant Peripheral Nerve Sheath Tumor in Parapharyngeal Space

Abstract

The malignant peripheral nerve sheath tumor is an extremely rare soft tissue sarcoma. It is a highly malignant sarcoma, which is locally invasive, frequently leading to multiple recurrences and eventual metastatic spread. The peak incidence of disease is known to occur sporadically between the age of 20s and 50s, and is usually associated with the neurofibromatosis type I. In human body, the trunk and extremities are the most commonly involved sites, with only 8-14% of all lesions appearing in the head and neck region. We present a case of malignant peripheral nerve sheath tumor involving the right parapharynx in a 48-year-old patient who complained of headaches in the right parietal area and of dysphagia that aggravated over a month. After surgery, tumor was finally diagnosed as malignant peripheral nerve sheath tumor by histopathologic examinations. The authors report a case of malignant peripheral nerve sheath tumor in the right parapharynx with a review of the literature.

Malignant peripheral nerve cell tumour

“…MPNST is also known as malignant schwannoma, neurofibrosarcoma, neurolemmoma and neurogenic sarcoma [5,6,21,22]. Malignant peripheral nerve sheath tumour (MPNST) is the coined term used by the WHO and corresponds to the malignant proliferation of any cell of the nerve sheath: Schwann cell, perineural fibroblast or endoneural fibroblast [3,23,24].…”

“…According to Enzinger and Weiss 1993, the term MPNST is preferred for these tumours because they may recapitulate the appearance of any cell of the Schwann cell and also the perineural fibroblast [3]. This tumour is usually found in lower extremities and retroperitonium and is rare in head and neck area [4][5][6][7][8][9]. The intraosseous localization of MPNST is very rare in literature [10]: Dahlin and Krishanan [11] reported 10 cases, Wirth and Bray [12] 31 cases, Bullock et al [13] 18 cases, and De la Monte et al [14] presented 60 histologically documented cases.…”

“…The diagnosis of MPNST has also been complicated by unclear criteria for determining the malignancy of a tumour originating in the nerve [15]. Since Harkin et al (1978) first reported plexiform schwannoma [16]; several authors have reported plexiform schwannoma unassociated with Von-Reckling Hausen's disease, which usually show benign histological features (Lee et al 2001); (Woodruff et al 1983); (Barbosa and Hansen 1984); and (Guarino 1993) (6,(17)(18)(19)(20). Here we report a case of intra-osseous malignant peripheral nerve sheath tumour of mandible in an 18-year-old female patient.…”

Surgical Approaches to Large Peripheral Nerve Sheets Tumors

“…We did not report other cases in rare location as isolated cases in the parapharyngeal region [16]. The tumors appear as a bosselated, sessile, circumscribed submucosal mass associated with pain or parathesia or muscle weakness and atrophy [16]. This slow enlarging mass exhibits rapid growth and two third of the lesions were more than 5 cm at the time of diagnosis [11].…”

“…We did not report other cases in rare location as isolated cases in the parapharyngeal region [16]. The tumors appear as a bosselated, sessile, circumscribed submucosal mass associated with pain or parathesia or muscle weakness and atrophy [16].…”