Malignant peripheral nerve tumors of the oral cavity

Malignant peripheral nerve sheath tumour of the oral and maxillofacial region-A systematic review

To integrate the available data published on malignant peripheral nerve sheath tumours (MPNST) of the oral and maxillofacial region. Searches in Embase, PubMed, Web of Science and Scopus were conducted for the identification of case reports/case series in English language. The risk of bias was assessed using the Joanna Briggs Institute tool. Outcomes were evaluated by Cox regression and Kaplan-Meier methods. A total of 306 articles were retrieved, 50 of which reporting 57 MPNST were included. The lesion showed a predilection for the mandible (n = 18/31.57%) of middle-aged adults (~40.5 years) with a male/female ratio of 1.1:1. The individuals were mostly symptomatic with a mean evolution time of 9.6 months. Surgical removal plus adjuvant therapy (especially radiotherapy) was the main approach (51.86%). Recurrence was reported in 39.62% of cases. Nodal and distant metastases were identified in 28.26% and 26.66% of cases, respectively. The 2-year cumulative survival rate was 55%. Independent predictors of poor survival were the presence of neurofibromatosis type 1 (p = 0.04) and distant metastases (p = 0.004). The diagnosis of MPNST is challenging due to the variety of its clinical and histopathological presentations. Local aggressiveness and the potential for metastases are common outcomes of this neoplasm.

An intraosseous malignant peripheral nerve sheath tumor of the lumbar spine without neurofibromatosis: Case report and review of the literature

A malignant peripheral nerve sheath tumor (MPNST) is defined as any malignant tumor that develops or differentiates from cells in the peripheral nerve sheath. This tumor is commonly associated with neurofibromatosis type 1 (NF1) and previous radiotherapy treatment. Primary intraosseous MPNSTs are extremely rare and a case of the lumbar spine in a patient without NF1 is reported in the present study, with a review of the intraosseous MPNST literature. A 45-year-old female presented with a 1-month history of severe lower back pain and pain radiating to the left leg. A total en bloc spondylectomy of L4 was performed. The postoperative histopathological diagnosis was MPNST with deletion of NF1, confirmed by dual-color fluorescence in situ hybridization (FISH) analysis. The tumor recurred 1 month following the surgery. Although adjuvant chemotherapy was administered, the patient succumbed due to intramedullary dissemination and carcinomatous meningitis 8 months following the initial consultation. NF1 deletion by FISH analysis may be particularly useful in distinguishing MPNST from other high-grade malignancies with overlapping morphological features.

Primary intraosseous malignant peripheral nerve sheath tumor: a case report and review of the literature

Primary intraosseous malignant peripheral nerve sheath tumors (MPNST) are exceptionally rare; the case reported here represents the first documented example occurring in the spinal column. The tumor arose in the second cervical vertebra of a forty year old woman of Asian origin. She had no stigmata of von Recklinghausen's disease (VRD). Plain radiographs and magnetic resonance imaging showed an osteolytic lesion within the expanded body of the vertebra. Histology revealed spindle-shaped tumor cells with nuclei showing pleomorphism, pallisading and mitotic activity. The cells stained positively for S-100 protein. The patient underwent stabilisation of the cervical spine and tumor excision as a two-stage procedure. She died of pulmonary metastases one year later. We have reviewed the literature on the pathology of these tumors.

Neurotropic malignant melanoma occurring in a stable burn scar

Malignant melanoma occurring in burn scars is extremely rare. Nine cases are reported in the literature. We report a case of a small malignant melanoma arising in a stable thermal burn scar after a long latent period of 58 years. The case was unique in that it was of the de novo neurotropic variant. Fascicles of amelanotic, S100 protein-positive atypical spindle cells with neuroid appearance infiltrated deeply in the scarred dermis and perineural spaces. The pigmentation of the lesion was due to solar lentigo instead of atypical melanocytic proliferation in the overlying epidermis.

Malignant melanotic schwannoma of the oral cavity

Intraoral malignant melanotic schwannoma is an extremely rare tumor. Two cases are presented, one occurring in the mandible of a 62-year-old man, the other in the maxilla of a 79-year-old man. The clinical presentation, light microscopic findings and immunohistopathological features are described. The difficulty of diagnosing this special tumor at initial presentation correctly, is discussed.

Malignant schwannoma of the gingiva

A case of malignant schwannoma on the buccal-attached gingiva in the right mandible is described. There was no evidence of multiple neurofibromatosis and the tumor was totally excised. Numerous closely-packed spindle-shaped cells showing marked mitotic activity were seen. The recognizable pattern of neurilemmoma could be observed focally in a small area of the tumor. At two years follow-up, the patient has remained symptom-free with no signs of metastasis.

[Neurogenic sarcoma of the head and neck with contact to the skull base (author's transl)]

The neurogenic sarcoma is a neoplasm found seldom. It descends from the sheaths of peripheric nerves. If this tumor develops from a solitary or multiple neurofibroma, it might also be called a neurofibrosarcoma. All other synonyms, especially that of the malignant schwannoma, should better be abandoned for histogenetic reasons. Today the classification of all tumors of the peripheral nervous system is based on a suggestion of the WHO from 1969. The tabular summary of the literature shows that only a little more than a hundred cases of neurogenic sarcoma of the head and neck were reported during the last 50 years. Differential diagnosis of this malignant tumor includes nearly all other malignant neoplasms of soft tissue, sometimes even anaplastic carcinoma. Histopathology, including electron microscopy, is described in general and also in detail with regard to three cases. Three forms of micro-morphological variants are dealt with, too. For diagnosis histological examination will be absolutely successful only in cases of neurofibromatosis or in cases where the nerve from which the tumor originates may be identified. Otherwise, conventional and computerized X-ray tomography may be helpful. Finally, some therapeutic and prognostic principles are discussed.