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.

Orbital malignant schwannoma and embryonal rhabdomyosarcoma in rats caused by leakage of locally injected nickel subsulfide to the orbit.

Nickel subsulfide (Ni3S2) is known to induce intraocular neoplasms when injected intravitreally into the eyes of rats. Here, we found two extraocular orbital neoplasms in two different rat strains, presumably due to the leakage of locally injected Ni3S2 to the extraocular orbital tissues. In the F344/DuCrlCrlj rat, an orbital mass arose at 30 weeks after injection, and invaded into the cranium. Histologically, the orbital mass was composed of areas arranged in parallel bundles formed by densely packed elongated or spindle-shaped cells with indistinct cytoplasmic borders, and of areas of hypocellular arrangement consisting of round cells in eosinophilic myxoid-like substances. Metastases were observed in the right submandibular and cervical lymph nodes. The neoplastic cells were immunopositive for S-100 protein and vimentin. Transmission electron microscopy revealed that the neoplastic cells had cellular processes and pericytoplasmic basal laminae. In the RccHanTM:WIST rat, an orbital mass arose at 36 weeks after injection. Histologically, the mass consisted of rhabdoid-like large round cells with proliferation of small round-to-polygonal cells, and these neoplastic cells infiltrated into the extraocular muscles. Immunohistochemically, the neoplastic cells were positive for desmin and vimentin. Transmission electron microscopy detected immature myofibrils with Z-band structures in the cytoplasm of these neoplastic cells. Consequently, the tumors were diagnosed as an orbital malignant schwannoma in an F344/DuCrlCrlj rat and an orbital embryonal rhabdomyosarcoma in a RccHanTM:WIST rat. The results of this case report suggest that leakage of Ni3S2 to the orbit caused the induction of orbital malignant schwannoma or rhabdomyosarcoma in rats.

Primary malignant schwannoma of the heart.

Primary malignant schwannoma of the heart is an extremely rare disease. We, herein, report a 42-year-old female who underwent successful surgical excision of such a tumor.

[Resection of a giant sacral schwannoma: case report and literature review]. / Udalenie gigantskoi nevrinomy v oblasti kresttsa: sluchai iz praktiki i obzor literatury.

Neurogenic sacral tumors are extremely rare. In most reported cases, this pathology was associated with neurofibromatosis. Sacral tumors manifest themselves at the stage when the neoplasm volume becomes giant, but these manifestations usually go unnoticed for the patient. Surgical approach to the sacral region is extremely challenging; intimate proximity of tumor capsule to vital organs, vessels, and nerves makes radical surgical treatment of these neoplasms rather difficult. A case report of radical resection of a schwannoma that was destroying the sacrum and continued to grow after radiotherapy is presented in this article.

Genetic dissection of the Mss4 locus mediating sex-biased cancer resistance in the rat peripheral nervous system.

The incidence of neural tumors is sexually dimorphic in both, humans and rodents. The identification of genetic determinants contributing to sex-biased tumor development is an essential prerequisite for differential tumor prevention in males and females. F2 hybrids of inbred BDIV and BDIX rats, resistant and susceptible, respectively, to ethylnitrosourea-induced malignant peripheral nerve sheath tumors (MPNST) display a marked sex bias regarding tumor risk. Homozygous BDIV alleles at the Mss4 locus (90.9-111.2 Mb, chromosome 6) mediate MPNST resistance exclusively in female F2 rats according to a genome wide association analysis. This locus was functionally confirmed and fine mapped through MPNST induction in males and females of three congenic rat strains (BDIX.BDIV-Mss4a, b, d). As a consequence, it could be subdivided in Mss4.1 (98.8-99.7 Mb) mediating cancer resistance, and Mss4.2 (99.7-111.2 Mb) enhancing sex specificity. Positional candidate genes were selected through DNA sequencing and expression profiling using RNAs from trigeminal nerve tissue of parental and congenic male and female animals. The transregulatory fingerprint of BDIV or BDIX alleles at Mss4.1 and/or Mss4.2, respectively, provided insight into the processes influencing cancer risk in a sex-biased way. A group of genes, a fraction of which involved in Schwann cell differentiation, showed low, male-biased expression in nerve tissues under the control of BDIX susceptibility alleles, but high, female-biased transcript levels when controlled by BDIV resistance alleles at Mss4. The Esr2 gene located in Mss4.1 constitutes an interesting functional candidate together with a yet unidentified gene/enhancer in Mss4.2.

[Malignant peripheral nerve sheath tumour of the infra-orbital nerve]. / Tumor maligno de vaina de nervio periférico afectando al nervio infraorbitario.

A malignant peripheral nerve sheath tumour (MPNST) is an uncommon neoplasm that rarely involves the head and neck region. It is even more infrequent for these tumours to affect cranial nerves. We report the case of a 53-year-old man who presented a MPNST involving the infra-orbital nerve, which extended through the orbit and the base of the skull, progressing intracranially. Histological studies identified the tumour as an MPNST. Response to radiotherapy was not complete and radical surgical resection was impossible, so the patient died 10months later. This rare case of MPNST with intracranial involvement illustrates the dismal prognosis for patients with these lesions. Prognosis is poor because of the difficulty of performing radical surgery with free margins in these locations.

Malignant schwannoma of the obturator nerve.

Lesions of obturator nerve are rare. Tumours and mainly malignant schwannoma of this nerve are extremely rare. The authors describe an unusual case of a gigantic schwannoma of the obturator nerve in 69 year old woman. Due to tumour expansion in the proximal part of the thigh MRI was performed and demonstrated extensive tumour originating most probably from the obturator nerve. The patient had no neurological symptoms. Biopsy from the lesion was taken at the Department of Orthopaedics with the following conclusion: malignant schwannoma. The patient received neoadjuvant chemotherapy due to diffuse metastatic spread on the chest X ray, after which metastatic spread subsided. The main lesion reduced its size by 1 cm. In 4 months after biopsy the patient was referred for operation to neurosurgery. The tumour was removed along its borders and except of minimal weakness of adduction of the right thigh there was no neurological deterioration. She was subsequently referred for further care to oncology and radiotherapy.The goal of this work is to emphasize the extremely rare occurrence of tumours of this nerve and suggest therapeutic options (Fig. 4, Ref. 11).

Proceedings of the 2013 Joint JSTP/NTP Satellite Symposium.

The first joint Japanese Society of Toxicologic Pathology (JSTP) and National Toxicology Program (NTP) Satellite Symposium, entitled "Pathology Potpourri," was held on January 29(th) at Okura Frontier Hotel in Tsukuba, Ibaraki, Japan, in advance of the JSTP's 29(th) Annual Meeting. The goal of this Symposium was to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers' presentations, including diagnostic or nomenclature issues that were presented, select images that were used for audience voting or discussion, and the voting results. Some lesions and topics covered during the symposium include: treatment-related atypical hepatocellular foci of cellular alteration in B6C3F1 mice; purulent ventriculoencephalitis in a young BALB/c mouse; a subcutaneous malignant schwannoma in a RccHan:WIST rat; spontaneous nasal septum hyalinosis/eosinophilic substance in B6C3F1 mice; a rare pancreatic ductal cell adenoma in a young Lewis rat; eosinophilic crystalline pneumonia in a transgenic mouse model; hyaline glomerulopathy in two female ddY mice; treatment-related intrahepatic erythrocytes in B6C3F1 mice; treatment-related subendothelial hepatocytes in B6C3F1 mice; spontaneous thyroid follicular cell vacuolar degeneration in a cynomolgus monkey; congenital hepatic fibrosis in a 1-year-old cat; a spontaneous adenocarcinoma of the middle ear in a young Crl:CD(SD) rat; and finally a series of cases illustrating some differences between cholangiofibrosis and cholangiocarcinoma in Sprague Dawley and F344 rats.

Widely infiltrating epithelioid malignant peripheral nerve sheath tumour of skull base.

The epithelioid variant of malignant peripheral nerve sheath tumours is a rare histological entity, and the occurrence of a malignant peripheral nerve sheath tumour in the skull base is even more unusual. We report a case of a 52-year-old man who presented with reduced hearing in the left ear, giddiness and left-sided facial weakness of short duration. He was a known hypertensive. On examination, left-sided 7th to 12th cranial nerve palsies were noted. Computed tomography (CT) and brain magnetic resonance imaging (MRI) were reported as an ill-defined heterogeneously enhancing mass left skull base suggestive of chondrosarcoma. Left tympanotomy and biopsy of the lesion were carried out. On light microscopy and immunohistochemical examination of the biopsy, a diagnosis of epithelioid malignant peripheral nerve sheath tumour was established. The patient underwent left extended modified radical mastoidectomy and selective neck dissection. Histopathological study of the resected surgical specimen confirmed left-sided extensive tumour involvement of skull base structures, as well as neck nodal metastases.

Case Report of a Patient With Malignant Peripheral Nerve Sheath Tumor Treated With Wide Resection.

Malignant peripheral nerve sheath tumors are soft tissue sarcomas originating from peripheral nerves. They are more frequently diagnosed in individuals with neurofibromatosis and tend to affect young men more often than women. The most common sites for these tumors within the peripheral nerve sheath are in the pelvis and the distal femur. Although chemotherapy and radiotherapy are not frequently used, it should be noted that in some cases, postoperative radiotherapy and chemotherapy may be beneficial. The primary treatment approach typically involves the complete surgical removal of the tumor. Here, we discuss the case of our patient whom we successfully treated with extensive resection and followed up with postoperative radiotherapy at our clinic.

A tonsillar location of a malignant schwannoma: a case report.

INTRODUCTION: Malignant schwannoma is a malignant tumor of differentiation of Schwann cells or perineural cells. OBSERVATION: The patient was a 74-year-old woman with no particular pathological history. She presented swallowing difficulty of solids and odynophagia, evolving for 1 year. Physical examination revealed a budding tumor of the left palatine tonsil without cervical adenopathy. The CT scan confirmed the lesions and the absence of tumor extensions. Histological and immunohistochemical examination of the biopsy sample of the tonsil tumor concluded to be a malignant schwannoma. The patient underwent a tonsillectomy with postoperative follow-up. DISCUSSION: Malignant schwannomas are aggressive tumors. They usually occur in young adults. They mainly affect nerves and soft tissues. Occurrence in the amygdala is rare. CONCLUSION: The association of malignant schwannoma of the palatine tonsil and advanced age is rare.

Giant Retroperitoneal Malignant Peripheral Nerve Sheath Tumor Treated with Multiorgan Resection: a Case Report and Review of the Literature.

Malignant peripheral nerve sheath tumors (MPNST) are rare. Although they originate from Schwann cells or pluripotent neural crest cells, they constitute less than 10% of all soft tissue sarcomas and more than 60% develop on the basis of neurofibromatosis. It is difficult to diagnose MPNST. Although it mostly occurs in the head and neck region or upper extremities, only 1% of cases are located in the retroperitoneal region. The main treatment is surgery, but survival results are not satisfactory even after surgery with R0 resection. They are not sensitive to chemotherapy and radiotherapy and tend to recur locally. The mass detected by imaging in a 57-year-old male patient who admitted to hospital with the complaint of abdominal pain was excised with clear surgical margins. The tumor was located in the left upper quadrant of the abdomen and seemed to invade the pancreas and left kidney in the computed tomography images. The patient had no history of neurofibromatosis or radiation. In this study, it was aimed to present our case diagnosed with retroperitoneal MPNST and treated with multiorgan resection, which is a rare entity, and to increase the awareness of clinicians about the diagnosis, treatment and prognosis of this rare tumor.

S100-negative epithelioid malignant peripheral nerve sheath tumor with possible perineurial differentiation.

Epithelioid malignant peripheral nerve sheath tumor (MPNST) is a rare subtype of MPNST composed of epithelioid cells with abundant cytoplasm. Currently, strong and diffuse immunostaining for S100 protein and SOX10 is generally regarded as a characteristic feature of epithelioid MPNST. However, malignant tumors with epithelioid morphology that arise from a peripheral nerve or a pre-existing benign nerve sheath tumor should be regarded as epithelioid MPNSTs when they do not show characteristic features that definitively lead to other specific diagnoses. Here, we describe 3 cases of epithelioid MPNST in the peripheral nerve or schwannoma that was negative for S100 protein and SOX10 expression. Instead, these tumors were positive for EMA, GLUT1, claudin 1, and cytokeratin to varying degrees, while all of them retained SMARCB1 and H3K27me3 by immunohistochemistry. EMA, GLUT1, and claudin 1 are known markers of perineurial cell differentiation; thus, they could possibly represent epithelioid MPNST with perineurial cell differentiation.

Malignant intracerebral nerve sheath tumor in a patient with Noonan syndrome: illustrative case.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) within the neuroaxis are rare, usually arising from peripheral and cranial nerves. Even more scarce are cranial subclassifications of MPNSTs termed "malignant intracerebral nerve sheath tumors" (MINSTs). These tumors are aggressive, with a strong tendency for metastasis. With this presentation, alongside resistance to adjunctive therapy, complete excision is the mainstay of treatment, although it is often insufficient, resulting in a high rate of mortality. OBSERVATIONS: The authors report the case of an adult patient with a history of Noonan syndrome (NS) presenting with slowly progressive right-sided hemiparesis and right-sided focal motor seizures. Despite initial imaging and histology suggesting a left frontal lobe high-grade intrinsic tumor typical of a glioblastoma, subsequent molecular analysis confirmed a diagnosis of MINST. The patient's neurological condition improved after gross-total resection and adjuvant chemo-radiation; he remains on follow-up. LESSONS: MINSTs are rare neoplasms with a poor prognosis; management options are limited, with surgery being the cornerstone of treatment. Reports on rare tumors such as this will increase awareness of this particular pathology and disclose clinical experience. In this case, the authors were unable to establish a definite cause-and-effect relation between NS and MINST. Nevertheless, it remains the first reported case in the literature.

Primary intrapulmonary malignant peripheral nerve sheath tumor: A rare case.

A rare case of malignant peripheral nerve sheath tumor (MPNST) was found in the lungs of a 68-year-old male patient. He was referred to our hospital because of visual disturbances, confusion, and headaches. Upon admission, a chest-Abdomen-Pelvis CT scan (CT scan of CAP) showed a right posterobasal pulmonary lesion process associated with liver metastases and a lytic lesion of the vertebral body of D3. Brain MRI (Magnetic Resonance Imaging) revealed secondary brain lesions above and below the tentorium. Image guided liver biopsy showed a suspicious site of malignancy. In the histopathological examination, a diagnosis of MPNST was established. A biological agent, Imatinib, was administered and the patient underwent cerebral radiotherapy. CT scan of CAP showed a partial tumor response according to Chun's criteria. Pre-existing literature indicates that MPNSTs with metastases to the brain are very rare and have a poor prognosis - survival after brain metastases would be about 10 months. Our case report agrees with the literature, as the disease stabilized with treatment up to 7 months, after which the patient was unreachable and our team lost track of him. Our case report appears to be one of the first cases of primary MPNST in the lungs with brain metastases.

Highly invasive intracranial malignant schwannoma in a rat.

A highly invasive intracranial malignant schwannoma containing several masses was detected in a 28-week-old male Crl:CD(SD) rat. Macroscopically, 3 masses were noted in the cranial cavity; one was present at the bottom of the cranial cavity and involved the trigeminal nerve, and the other two were in the parietal bone. Histologically, each mass consisted of fusiform cells with interlacing fascicular, wavy and nuclear pseudopalisading arrangements and round cells with cystic lesions. The tumor cells invaded not only the brain but also the parietal bone. In the brain, the tumor cells infiltrated diffusely into the leptomeningeal and perivascular spaces and parenchyma, in which the tumor cell morphology and invasive pattern closely resembled those of malignant astrocytoma and malignant reticulosis. Immunohistochemically, the tumor cells in the masses showed positive reactions for both S-100 protein and GFAP, while those in the cerebral invasion sites were negative for GFAP and less positive for S-100 protein. Electron microscopically, a single basal lamina layer and short intricate cell processes were confirmed in the tumor cells. From these results, the present tumor was diagnosed as a malignant schwannoma arising in the cranial cavity, probably originating from the trigeminal nerve. The present tumor is considered to be a relatively unique malignant schwannoma based on its growth and invasion patterns.

Primary Malignant Peripheral Nerve Sheath Tumor of the Trachea: a Case Report with Brief Review of Literature.

Malignant schwannoma, also called malignant peripheral nerve sheath tumor (MPNST), is a rare and aggressive tumor arising from the nerve sheath. We describe a rare case of endotracheal malignant peripheral nerve sheath tumor occurring in a middle-aged male who presented with asthma-like symptoms for 6 months with progressively increasing dyspnea. A computed tomogram (CT) scan of the thorax revealed near complete luminal obstruction of the trachea by a mass lesion at the level of the second and third tracheal rings. Microlaryngotracheoscopy revealed a fleshy pedunculated growth arising from the left side of the second and third tracheal rings and obliterating almost the entire tracheal lumen. Intraluminal complete excision of the mass was done. Later, he underwent excision of the 2nd and 3rd rings after the histopathology revealed MPNST. Patient after 28 months of follow-up is free of disease.

Successful Surgery Management of Giant Periorbital Malignant Schwannoma in a Low-Income Setting.

Schwannoma can arise from any cranial, peripheral or autonomic nerve, except the olfactory and optic. About 25-45% of extracranial schwannomas lie in the head and neck. Data on malignant schwannoma from low-income settings are inconsistent. We reported a case of giant periorbital malignant schwannoma successfully treated in a low-income setting. The strength of our case is given not only by the rarity and the size of the disease but also for highlighting the weakness of health system in low-resource settings. It is mandatory to strengthen the health system with particular attention to physical, psychologic and social aspects and to promote comprehensive programs including all these aspects.

An unusual presentation of intraosseous malignant peripheral nerve sheath tumour of mandible.

Malignant peripheral nerve sheath tumour (MPNST) is a rare mesenchymal tumour which usually presents high grade malignancy. We report an atypical case of intraosseous malignant peripheral nerve sheath tumour on mandible in a 36-year-old male. Patient presented with an incidentally discovered radiolucency on the left anterior mandible and did not complain of any symptoms. Panoramic radiograph and computed tomography showed enlargement of inferior alveolar nerve canal, thinning of the cortex and calcified foci within an expansile mass. Magnetic resonance images revealed heterogeneous hyperintense signal intensity with a well-defined margin on T2 weighted images, heterogeneous enhancement on contrast-enhanced T1 weighted images and intermediate signal intensity and inferior alveolar nerve canal enlargement on T1 weighted images. In spite of benign radiologic characteristics as mentioned above, histopathologic examination of biopsied specimen otherwise revealed a low-grade malignancy. Wide excision of mandible was performed and there has been no loco-regional recurrence or distant metastasis over 1 year following surgery. This case indicates that, even when imaging modalities clearly demonstrate benign nature of intraosseous neurogenic tumour, care must be taken to establish proper treatment plan for assumed malignancy with a definitive histopathological analysis.

Intracranial Malignant Nerve Sheath Tumor in the Middle Cranial Fossa: A Rare Case Report with Review of Literature.

Intracranial malignant nerve sheath tumors rarely arise in the central nervous system. They usually arise from the cranial nerves, though rare cases of intraparenchymal lesions have also been reported. We report a case of malignant nerve sheath tumor located in the right middle cranial fossa. Preoperatively, the lesion resembled a meningioma arising from the petrous temporal bone. The lesion was completely excised. Postoperatively, the patient developed righted-sided complete facial nerve palsy. Histopathology and immunohistochemistry revealed the lesion to be a malignant nerve sheath tumor. The development of postoperative facial nerve palsy was puzzling but could be explained if we consider the possibility of the lesion arising from the facial nerve near the geniculate ganglion. Intracranial malignant nerve sheath tumor centered over the geniculate ganglion and projecting into the middle cranial fossa is uncommon, and to the best of our knowledge, only one such case has been previously reported. We review the relevant literature, discuss the management and add to the previously reported cases of this rare condition.