Cutaneous Malignant Peripheral Nerve Sheath Tumor

Cutaneous malignant peripheral nerve sheath tumors (MPNSTs) are rare sarcomas of neuroectodermal origin arising in the dermis and/or subcutis. In contrast with their deep soft tissue and visceral counterparts, cutaneous MPNSTs are rarely associated with neurofibromatosis type 1. Two main subtypes of cutaneous MPNST can be distinguished histologically: conventional (ie, spindle cell) and epithelioid MPNST. The 2 subtypes also differ in predilection for deep versus superficial locations, association with preexistent benign peripheral nerve sheath tumors and S100 immunohistochemistry. Herein, we review current knowledge of cutaneous MPNST and discuss its differential diagnosis.     

Malignant peripheral nerve sheath tumor arising from the colon in a newborn: report of a case and review of the literatures

A malignant peripheral nerve sheath tumor (MPNST) is a rare neoplasm arising from peripheral nerve sheath. Here, we report the first case of MPNST arising in the colon and also the youngest case of MPNST in the gastrointestinal tract. The patient was a 2-day-old neonate with symptoms and signs of intestinal obstruction. The patient had no family history or stigmata of neurofibromatosis type 1. A computed tomographic scan revealed a 5-cm-sized mass in ascending colon causing intestinal obstruction, and emergent right hemicolectomy was performed.The microscopic examination showed atypical spindle cells with hyperchromatic nuclei and high mitotic activity. The results of immunohistochemical staining, which showed positivity for S-100 and vimentin as well as negativity for smooth muscle actin, CD34, and c-Kit, supported the final diagnosis of MPNST. Genetic analysis of the patient revealed no abnormalities.After surgery, the patient recovered uneventfully and has been free of the disease for 17 months.     

Primary Intraosseous Malignant Peripheral Nerve Sheath Tumor of the Medial Cuneiform: A Case Report and Review of the Literature

Peripheral nerve sheath tumors (benign and malignant) usually arise in the soft tissues and are unusual in bone. Intraosseous peripheral nerve sheath tumors are usually benign and constitute approximately 0.2% of all bone tumors. Intraosseous malignant peripheral nerve sheath tumors (MPNSTs) are uncommon and usually result from secondary invasion. Only a few cases of primary intraosseous MPNSTs have been reported in published studies, and these were localized mostly in the mandible (approximately 50%) or maxilla, spine, and, occasionally, in the appendicular skeleton. To the best of our knowledge, we report the first case of primary intraosseous MPNST involving a midtarsal bone (medial cuneiform). The patient was a 62-year-old female who presented with pain and tenderness but without swelling. Imaging revealed nonspecific findings, and the preoperative computed tomography-guided biopsy findings were consistent with MPNST. The patient was treated with neoadjuvant radiotherapy, followed by wide local excision and allograft reconstruction. At the final follow-up examination (24 months), the graft had been incorporated without evidence of local recurrence or distant disease. The patient with primary intraosseous MPNST of the medial cuneiform described in the present report presented with nonspecific clinical and radiologic findings. Thus, a high index of suspicion and histopathologic examination, including immunohistochemistry, are necessary for an accurate diagnosis.     

Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation

Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife is an innovation in these tumors’ management.     

Malignant peripheral nerve sheath tumor of kidney—A case report

INTRODUCTIONMalignant peripheral nerve sheath tumors (MPNSTs) are very rare soft-tissue tumors. These tumors originate from Schwann cells or pluripotent perineural cells of the neural crest. An isolated MPNST of the kidney is extremely rare and has been reported in only six cases to date.PRESENTATION OF CASEA 30-year-old female with an unremarkable past medical and surgical history presented with an enlarging, right-sided abdominal mass for the last 3 months. A CT scan of the abdomen and pelvis showed a large exophytic mass arising from the right kidney. A metastatic work-up was negative, so a right radical nephrectomy was performed. Histopathological and immunohistochemical studies confirmed the diagnosis of an MPNST.DISCUSSIONMPNSTs are rare and aggressive soft-tissue sarcomas that are usually associated with neurofibromatosis type 1 (NF-1) but that also occur post-radiation and sporadically. These tumors are highly malignant neoplasms with a high recurrence rate and distant metastases. Complete surgical excision remains the mainstay of treatment due to the limited response of MPNSTs to both chemotherapy and radiotherapy.CONCLUSIONMPNSTs arising from the kidney are very rare. Complete surgical resection provides the only hope for cure. Postoperative chemotherapy and radiotherapy are still controversial, although postoperative radiotherapy is currently recommended by an oncology consensus group.     

Intrasellar malignant peripheral nerve sheath tumor (MPNST)

Summary Intracranial malignant peripheral nerve sheath tumors (MPNST) and intrasellar schwannomas are rare tumors. We describe a case of an intrasellar schwannoma with progression to a MPNST, a finding that, although very rare, extends the differential diagnosis of intrasellar lesions.     

Would a Massive Intra-abdominal Malignant Peripheral Nerve Sheath Tumor with Growth into the Inguinal Canal and Scrotum Preclude Surgical Option? A Case Report and Review of Literature

Malignant peripheral nerve sheath tumors (MPNST) are rare spindle-cell sarcomas derived from Schwann cells or pluripotent cells of the neural crest accounting for less than 10 % of all soft tissue sarcomas. They arise from major or minor peripheral nerve fibers or their sheaths. The World Health Organization coined the term MPNST for tumors of neurogenic origin with similar biological behavior replacing all the previous heterogeneous and, often, confusing nomenclature including malignant schwannoma, malignant neurilemmoma, and neurofibrosarcoma. The retroperitoneum and the lower extremities are the most common sites, but MPNST may arise anywhere in the body. Its location in the retroperitoneum in a patient without neurofibromatosis is an exceedingly rare occurrence. Imaging is routinely performed to assess the extent of the disease and to plan surgical resection. Surgical resection is the first line of therapy, ideally with total removal of the tumor. Owing to a high risk of recurrence with incomplete resection, postoperative irradiation and chemotherapy are necessary; however, they are often used as adjuvant therapy even if the tumor is completely resected.     

Metastasizing malignant peripheral nerve sheath tumor initially presenting as intracerebral hemorrhage. Case report and review of the literature

BACKGROUND: Malignant peripheral nerve sheath tumors, infrequent sarcomas arising within a peripheral nerve, mostly metastasize to the lung at terminal stage of disease. However, metastasis to the brain without pulmonary involvement is quite unlikely to occur. CASE DESCRIPTION: A 21-year-old man was brought in the emergency department due to sudden unconsciousness, and imaging studies showed huge intracerebral hemorrhage. Surgical removal and adjuvant therapy was performed for pathologically proven MPNST. Concurrent painful chest masses were also confirmed as MPNST through surgical resection. Nine months after craniotomy, multiple masses in the lung field and axilla region were uncovered, and surgical resection followed. Despite postoperative irradiation, the patient died of the respiratory complications at 16 months after craniotomy. CONCLUSION: To our knowledge, this kind of metastatic cerebral bleeding is the first case that was ever reported. The MPNST actually can exhibit an apoplectic manifestation even without pulmonary involvement in a young adult, albeit this is quite rare. Thus, high index of suspicion should be paid to minute complaints regarding MPNST in peripheral locations so as not to overlook an advanced or metastasized disease.     

Sporadic malignant nerve sheath tumour of the oculomotor nerve

Malignant peripheral nerve sheath tumours (MPNST) are exceedingly rare in an intracranial location. In this report clinical and pathological evidence for the diagnosis of a MPNST arising from of the oclumotor nerve is presented. To our knowledge this is the first such case reported in the medical literature.     

Clinical Relevance of Pathological Grades of Malignant Peripheral Nerve Sheath Tumor: A Multi-Institution TMTS Study of 56 Cases in Northern Japan

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a relatively rare soft tissue tumor, and its clinical relevance of pathological grades remains obscure. METHODS: Fifty-six cases of MPNST identified from the files of seven oncology centers of the Tohoku Musculoskeletal Tumor Society (TMTS) and National Cancer Center were analyzed for histologic grades, demographics, treatments, and prognostic factors. The average follow-up period was 41 months. RESULTS: Twenty-two men and 34 women with a mean age of 45 years were involved. Forty-four (78.6%) of 56 tumors were in the lower extremity or trunk. Fifty tumors (89%) were classified as high grade, and the remaining six as low grade. Twenty-one (39.6%) of 53 patients who underwent tumor excision developed local recurrences. An axial site and inadequate surgical margin were defined as risk factors for local recurrence. The overall survival rates of the 56 patients were 55.1% at 3 years and 43.3% at 5 years. Univariate analysis of the 56 patients revealed large-sized tumors, metastasis at presentation, and histologically high grade were significantly associated with poor prognosis. Multivariate analysis revealed a large tumor and metastasis at presentation to be independent prognostic factors. CONCLUSIONS: The current study involving 56 patients with MPNST showed the aggressive clinical behavior of the tumor. Large-sized tumors, metastasis at presentation, and high histological grade were related to poor prognosis on univariate analysis, but independency of histological grade was still obscure. In the treatment for a large and high-grade MPNST, an alternative strategy should be further considered.     

原发性膀胱神经鞘瘤1例报告并文献复习

目的 探讨原发于膀胱的神经鞘瘤和恶性周围神经鞘瘤在组织病理学、临床表现、治疗和预后上的特点,确立两者的鉴别诊断思路.方法 回顾1例原发于膀胱的神经鞘瘤的临床诊疗过程,结合有关膀胱神经鞘瘤及膀胱恶性周围神经鞘瘤的文献资料进行分析.结果 在组织病理和免疫组化方面,原发于膀胱的神经鞘瘤和恶性周围神经鞘瘤有明显差异.结论 原发于膀胱的神经鞘瘤临床极其少见,易与膀胱常见肿瘤混淆,造成误诊,免疫组化为重要的确诊依据.膀胱恶性周围神经鞘瘤应以高度恶性的软组织肉瘤进行处理.临床上应重视两种疾病的鉴别,以正确地指导临床诊疗.     

A case of malignant peripheral nerve sheath tumor originating from the cervical vagus nerve

A 45-year-old female presented a peripheral nerve sheath tumor (MPNST), which had progressed to malignancy from a neurofibroma arising in the left cervical vagus nerve. Neuroimaging showed that a tumor grew in the left neck area of the patient, involving the internal carotid and vertebral arteries, and invading the intracranium through the left jugular foramen. The tumor was extensively removed using a combination of the lateral suboccipital approach and the neck incision, and the frontotemporal approach accompanied with EC-IC highflow bypass and EC-MCA anastomosis. Postoperatively, pathological features demonstrated a MPNST arising from the cervical vagus nerve. Here, we discuss the clinical behavior of MPNST by quoting previous reports, and conclude by emphasizing 2 points in the treatment of MPNST; 1) that prognosis of patients with MPNST is greatly affected by the time between presenting symptoms and diagnosis, and 2) that it is very important to carefully observe neurofibroma patients, because there is a possibility of progression to malignant MPNST.     

Metastatic malignant melanoma resembling malignant peripheral nerve sheath tumor: report of 16 cases

We report 16 cases of metastatic malignant melanoma presenting clinically as lymphadenopathy or a soft-tissue mass and histologically resembling malignant peripheral nerve sheath tumor (MPNST). In two cases, the metastatic malignant melanoma was preceded by a primary cutaneous malignant melanoma; in four cases, it presented synchronously with such a tumor; and in 10 cases, there was no evidence of a previous or concomitant malignant skin lesion. Histologically, the tumors were characterized by a malignant-appearing spindle cell proliferation arranged in fascicles, often accompanied by a peritheliomatous growth pattern, alternating hypercellular and hypocellular areas, numerous mitoses, and foci of necrosis. In nine cases, there was residual lymph node tissue. In none of the cases was there evidence of an anatomic connection with a nerve, a coexistent neurofibroma, or the stigmata of neurofibromatosis. Fourteen of the cases showed strong and generally diffuse immunoreactivity for S-100 protein, and five cases showed positivity for HMB-45. Four of eight patients with follow-up information died of the disease. Tumors with a microscopic appearance compatible with MPNST but showing strong diffuse S-100 protein staining and featuring remnants of lymph node may represent metastatic malignant melanomas and should elicit a search for a previous or concomitant tumor in the skin and other sites. The similarities these tumors share with MPNST are probably related to their common neuroectodermal histogenesis.     

A rare case of a solitary peripheral nerve sheath sarcoma of the scalp

Summary Malignant peripheral nerve sheath tumors are rare and most often appear in the clinical setting of von Recklinghausen's neruofibromatosis. On rare occasions they are seen in patients lacking any of the overt stigmata of this systemic disease. We report on a case of a peripheral nerve sheath sarcoma (PNSS) on the scalp and the back of the neck of a 13-year-old female arising in a solitary benign neurofibroma with no evidence of systemic neurofibromatosis. The tumor was examined by ultrastructural and immunohistochemical techniques as well as by routine histopathology. It was defined as a peripheral nerve sheath sarcoma, fibrosarcomatous type, of poorly differentiated perineurial cell origin. The possible significance of histogenetic subclassification in terms of surgical management and the oncological approach as well as the prognosis is discussed.     

Malignant peripheral nerve sheath tumour of penis

Malignant peripheral nerve sheath tumour (MPNST) is a rare variety of soft tissue sarcoma that originates from Schwann cells or pluripotent cells of neural crest origin. They have historically been difficult tumours to diagnose and treat. Surgery is the mainstay of treatment with a goal to achieve negative margins. Despite aggressive surgery and adjuvant therapy, the prognosis of patients with MPNST remains poor. MPNST arising from penis is a very rare entity; thus, it presents a diagnostic and therapeutic challenge. We present a case of penile MPNST in a 38‐year‐old man in the absence of neurofibromatosis treated with surgery followed by post‐operative radiotherapy to a dose of 60 Gray in 30 fractions and adjuvant chemotherapy with ifosfamide and adriamycin.     

Long-term survival after removal of a malignant peripheral nerve sheath tumor originating in the anterior mediastinum

Malignant peripheral nerve sheath tumors (MPNSTs; malignant schwannomas) rarely occur in the anterior mediastinum, and their prognosis is poor. A 75-year-old man was referred to our hospital for examination of an anterior mediastinal tumor. A computed tomography-guided percutaneous needle biopsy revealed only fibrosis. The tumor was completely excised via a median sternotomy with partial resection of the pericardium and right upper lobe of the lung. Thereafter, the tumor was diagnosed as a storiform-pleomorphic type of malignant fibrous histiocytoma. At 1 year after the surgery, a distant metastasis was found in the interlobular space between the right middle and lower lobes. The tumor was completely excised via a right posterolateral thoracotomy. Reexamination of the primary and secondary tumors revealed an MPNST. No recurrence was found up to 5 years after the second surgery without adjuvant chemotherapy or radiation therapy. However, he died from multiple lung metastases after 6 years.     

Malignant peripheral nerve sheath tumor with Horner's syndrome: a case report

We report on a 42-year-old woman with malignant peripheral nerve sheath tumor (MPNST) arising from the cervical sympathetic nerve. A collar incision and partial sternotomy were performed at the second intercostal space. The mass was spindle shaped and connected to the sympathetic trunk on the cranial and caudal sides, and it compressed the left carotid sheath on the median side. After the patient's uneventful recovery from surgery, adjuvant radiotherapy was administered to the area of resection. The patient remains well 5 years after surgery with no evidence of recurrence.     

Malignant triton tumor of the gluteal region in a patient unaffected by neurofibromatosis: A case report

Malignant triton tumor (MTT) is a rare variant of malignant peripheral nerve sheath tumor (MPNST) made up of both malignant schwannoma cells and malignant rhabdomyoblasts.A 26-years-old male patient was admitted with an asymptomatic gluteal mass. Magnetic resonance imaging showed heterogeneous soft tissue mass and he underwent open biopsy. Malignant peripheral nerve sheath tumor was diagnosed. He was given adjuvant chemotherapy following the removal of the tumor with hip disarticulation. The tumor was diagnosed as “malignant triton tumor” based on pathological examination including immunohistochemical studies. There were no signs of metastasis but recurrence was observed at 9 months follow up.MTT is usually associated with Neurofibromatosis 1 and located in head, neck region. In this case sporadic involvement of gluteal region and aggressive behavior of the lesion despite radical surgery was demonstrated.     

Sporadic Multifocal Malignant Peripheral Nerve Sheath Tumor—A Rare Presentation

Malignant peripheral nerve sheath tumors(MPNST) are uncommon neoplasms with an incidence of 0.001% in general population. Multifocality is a rare manifestation of MPNST . A case of a 65 year old patient who presented with multiple swellings involving the neck, extremity and back without associated neurofibromatosis is reported for its rarity of presentation.. Diagnosis was made by FNAC and confirmed by peroperative findings and histopathology.