Malignant peripheral nerve sheath tumour of median nerve - an unusual presentation: a case report

Malignant peripheral nerve sheath tumours (MPNST) are rare tumours, which usually occur in patients with multiple neurofibromatosis. They are common in the head and neck and trunk and only a few cases have been reported in the hand. Many of these occur in patients with von Recklinghausens disease and rarely as a malignant transformation of benign schwannomas. When they appear in the hand they often present with various symptoms. We encountered a patient who presented with a longstanding asymptomatic swelling of the palm. On excision the histopathology showed a high-grade malignant peripheral nerve sheath tumour, which led us to speculate that a malignant transformation had occurred in a pre-existing benign swelling. This is reported for its unusual presentation, which, to our knowledge, has never been described previously.     

Malignant peripheral nerve sheath tumour of the trigeminal nerve: case report and literature review

Although all trigeminal nerve schwannomas are uncommon, malignant schwannomas are extraordinarily rare. We describe a patient who presented with clinical and radiological features of a trigeminal schwannoma; however, pathological analysis showed a malignant peripheral nerve sheath tumour (WHO Grade IV). We discuss these extremely rare tumours and their management.     

Peripheral and Cranial Nerve Sheath Tumors—A Clinical Spectrum

To analyze the incidence of nerve sheath tumors in a tertiary care hospital over a period of 5 years and review the literature. Medical case records from last 5 years were retrieved and histopathology and operative details were studied in a retrospective analysis. There is a slight male preponderance when it comes to nerve sheath tumors and acoustic schwannomas accounted for the largest fraction among schwannomas. Nerve sheath tumors include a wide spectrum of schwannomas, neurofibromas and malignant peripheral nerve sheath tumors. Hence combination of clinical, pathological and surgical expertise is needed to diagnose accurately.     

Benign spinal nerve sheath tumors: their occurrence sporadically and in neurofibromatosis types 1 and 2.

Benign spinal nerve sheath tumors (neurofibromas and schwannomas) often occur on dorsal nerve roots sporadically or in neurofibromatosis types 1 and 2. These are histologically benign tumors, and distinction between them is frequently not made by clinicians. To determine if there is a correlation between the histological pattern of benign spinal nerve sheath tumors and the type of neurofibromatosis, the clinical and pathological features of these tumors (86 surgical specimens and five autopsies) in 68 patients were reviewed. The patients were classified into one of four categories: neurofibromatosis type 1, neurofibromatosis type 2, uncertain, or sporadic. The diagnostic criteria used for neurofibromatosis types 1 and 2 were established by the National Institutes of Health. Patients who did not fulfill criteria for either neurofibromatosis type 1 or 2 but who had multiple nervous system tumors or other stigmata of neurofibromatosis were designated "uncertain." Spinal nerve sheath tumors were considered sporadic in 42 cases (40 schwannomas and two neurofibromas). In the 14 patients with neurofibromatosis type 1, all spinal nerve sheath tumors were neurofibromas. In six of the seven patients with neurofibromatosis type 2, all spinal nerve sheath tumors were schwannomas. One patient with neurofibromatosis type 2 had a spinal nerve sheath schwannoma and a tumor with features of both tumor types. The authors conclude that spinal nerve sheath tumors in patients with neurofibromatosis type 1 are neurofibromas. In contrast, spinal nerve sheath tumors occurring in neurofibromatosis type 2 or sporadically are most frequently schwannomas. The distinct histological features of these tumors may reflect different pathogenetic mechanisms even though they arise at identical sites in neurofibromatosis types 1 and 2.     

Expanding the spectrum of malignant change in schwannomas: epithelioid malignant change, epithelioid malignant peripheral nerve sheath tumor, and epithelioid angiosarcoma: a study of 17 cases

Schwannomas (neurilemmomas) rarely undergo malignant change, most often in the form of either malignant peripheral nerve sheath tumor (MPNST) or angiosarcoma. We characterize the clinical features and the histopathologic spectrum of 17 schwannomas with evidence of malignant change. The study group comprised 7 males and 10 females with an age range of 16 to 76 years, (median, 40 yrs). None of the patients had neurofibromatosis. Lesions ranged in size from 0.6 to 10.5 cm (median, 4.0 cm) and arose mainly in the limbs/limb girdles (7 cases) or head and neck region (7 cases). All tumors contained areas of conventional benign schwannoma. Four cases of pure epithelioid malignant peripheral nerve sheath tumor (EMPNST) were identified, three of which showed immunopositivity for S-100 protein. Four angiosarcomas were identified, predominantly epithelioid-type. Ten schwannomas had an appearance that we have designated epithelioid malignant change (EMC) and, in one of these, EMC coexisted with EMPNST. Large epithelioid cells with abundant eosinophilic cytoplasm, vesicular chromatin, and prominent nucleoli (morphologically similar to cells of EMPNST) were distributed throughout the schwannoma--singly, in clusters, and in one case a microscopic nodule of such cells was also present. These large epithelioid cells were strongly positive for S-100 protein. Although follow-up data so far are limited, 1 of 5 patients with EMC in whom meaningful follow up was available developed repeated local recurrence (median follow up, 21 mos), one patient each with EMPNST and angiosarcoma died of local and metastatic disease. Pure EMPNST is rare; however, we confirm the tendency of MPNST to show epithelioid cytomorphology when arising in a benign schwannoma. We also confirm the distinctive (albeit infrequent) tendency of angiosarcoma to arise in schwannomas. We describe EMC in schwannomas and suggest that this represents a putative precursor lesion of EMPNST. At this time, we do not have an explanation for the tendency of schwannomas to show epithelioid cytomorphology when they undergo malignant change.     

Retroperitoneal Peripheral Nerve Sheath Tumour of Triton Type—A Case Report

The malignant peripheral nerve sheath tumour is the malignant counterpart to benign soft tissue tumours such as neurofibromas and schwannomas. Malignant Triton Tumour is a histological variant of malignant peripheral nerve sheath tumours with rhabdomyosarcomatous differentiation. They are known to develop in cases of neurofibromatosis type 1 (von Recklinghausen’s disease). Malignant peripheral nerve sheath tumor is biologically an aggressive tumour for which the treatment of choice is surgery. Here we report a rare case of malignant peripheral nerve sheath tumour, not associated with neurofibromatosis type 1 and arising in the retroperitoneum.     

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.     

Tumors of the brachial plexus

Over a 17-year period, 56 patients with 57 tumors involving the brachial plexus were operated upon. The 40 neural sheath tumors included 26 neurofibromas, 8 schwannomas, 4 malignant neural sheath tumors, 1 fibrosarcoma, and 1 meningioma. Nine of the neurofibromas were associated with von Recklinghausen's disease (VRD), and 2 others were what was termed regionalized neurofibromatosis characterized by involvement of one limb with extension along the course of one or more plexus elements. Seventeen tumors were not of neural sheath origin; 7 were benign and 10 were metastatic malignant tumors compressing or invading the plexus. Benign neurofibromas and malignant sheath tumors almost always presented with pain or functional neural deficit, whereas schwannomas often presented with a palpable mass as their only initial symptom. Patients with solitary neurofibromas were significantly older, often female, and more likely to have tumor on the right side than patients with schwannomas, malignant neural sheath tumors, or neurofibromas associated with VRD. Solitary neurofibromas could often be totally resected without added deficit by sacrificing fascicles entering and leaving tumor that were determined to be "nonfunctional" by intraoperative nerve action potential recordings. Resection of neurofibromas associated with VRD sometimes but not always resulted in significant loss. Operation is nonetheless recommended, especially when malignancy is suspected because of rapidly increasing size, when severe pain or neural deficit is present, or when compression of adjacent plexus elements is a concern. Schwannomas and benign non-neural sheath tumors can usually be extirpated without damage to plexus elements. Forequarter amputation is advised for malignant intrinsic tumors involving distal plexus elements even though gross total resection seems feasible.     

Case studies for illustration and discussion: peripheral nerve tumors

This article gives a presentation of a variety of surgical cases of peripheral nerve tumors for illustration and discussion. The first three cases include a schwannoma, a neurofibroma, and a desmoid tumor of the brachial plexus region. Case 4 is that of a patient with a common peroneal ganglion cyst, and case 5 is that of a patient with an angiolipoma of the forearm. Cases 6 through 8 illustrate a plexiform neurofibroma, a malignant peripheral nerve sheath tumor, and a metastatic carcinoma to the brachial plexus region. In case 9, a patient with schwannomatosis was treated for multiple spinal schwannomas.     

Melanocytic Malignant Peripheral Nerve Sheath Tumor of the Male Breast

Summary

Background

Malignant peripheral nerve sheath tumors are rare tumor entities that originate from peripheral nerve sheaths and have an unfavorable prognosis. Common sites include deeper soft tissues, usually in the proximity of a nerve trunk. Breast is an absolutely rare location of this lesion, and presentation as a breast lump in the male breast is even rarer.

Case Report

A 65-year-old man presented with a 6-month history of a painless mass of the left breast. Tissue biopsy was performed. Histopathology revealed a malignant spindle cell tumor which was confirmed to be a melanocytic malignant peripheral nerve sheath tumor on the basis of immunopositivity for HMB45 and S-100.

Conclusion

There are no generally accepted guidelines for the treatment of malignant peripheral nerve sheath tumors in the male breast. The patient was referred for radiation therapy after simple mastectomy.Key Words: Malignant peripheral nerve sheath tumor, Breast, Melanocytic     

Malignant peripheral nerve sheath tumor of the vagus nerve in a teenager with the neurofibromatosis 1 gene mutation: a case report

Malignant peripheral nerve sheath tumors account for approximately 5% to 10% of all soft tissue sarcomas in which 25% to 50% are diagnosed in patients with neurofibromatosis 1 (NF1). Tumors are often located in the proximal portion of the upper and lower extremities and trunk, whereas cervical vagus nerve localizations are extremely rare, and the English literature is limited to isolated case reports. Malignant peripheral nerve sheath tumors usually affect adults. However, earlier presentation is described in patients with the NF1 mutation. The authors describe a very rare case of malignant peripheral nerve sheath tumor of the vagus nerve in a teenage patient with NF1 focusing on surgical management of this uncommon pathology and its histopathologic features to underline the importance of differential diagnosis and early treatment of this rare and aggressive tumor.     

Salvage of the Foot for Recurrent Malignant Peripheral Nerve Sheath Tumor

Malignant peripheral nerve sheath tumors are rare soft tissue tumors accounting for 3% to 10% of all soft tissue tumors. They are strongly related to neurofibromatosis type 1, an autosomal dominant disease, and are characterized by aggressive biologic behavior, high local recurrence rates, and frequent metastases. Although the major nerves of the lower extremities are a common location of these tumors, scarce cases have been reported of malignant peripheral nerve sheath tumors involving the interdigital nerves of the foot. We report the case of a patient with non-neurofibromatosis type 1 and a recurrent malignant peripheral nerve sheath tumor of the first interdigital nerve of the foot treated successfully with limb salvage surgery with wide resection margins and reconstruction with an autogenous fibula graft.     

Aspects histopathologiques des principales tumeurs des nerfs périphériques

Benign tumors of the peripheral nerves come from ectodermic tissues. This chapter describes the most common forms: the schwannomas and the neurofibromas. Schwannomas have two possible patterns of cells: Antoni A and B types. Neurofibromas are most often associated with neurofibromatosis NF₁ and may be localized, diffuse, or plexiform. The benign tumor structures account for the fact that they can be removed with or without preserving the concerned nerve. Malignant tumors (malignant peripheral sheath tumors) come from degeneration of neurofibromas in two out of three cases and have a poor prognosis.     

Malignant peripheral nerve sheath tumor of the kidney

Malignant peripheral nerve sheath tumors are rare in the genitourinary organs, with few reports of occurrence in the kidney. We describe a patient with a renal malignant peripheral nerve sheath tumor, discovered after excision of a malignant peripheral nerve sheath scalp lesion, with additional masses in the lung and shoulder on metastatic evaluation. This patient underwent neoadjuvant intravenous doxorubicin therapy, followed by surgical resection of the scalp, lung and shoulder lesions in addition to a radical nephrectomy.     

Recognizing schwannomatosis and distinguishing it from neurofibromatosis type 1 or 2

BACKGROUND DATA: Schwannomatosis has become a newly recognized classification of neurofibromatosis. Although the genetic loci are on chromosome 22, it lacks the classic bilateral vestibular schwannomas as seen in NF-2. We present the surgical treatment of 4 patients with schwannomatosis, including a brother and sister. METHOD: Case 1 presented with multiple progressively enlarging peripheral nerve sheath tumors. Case 4 presented with a trigeminal schwannoma and a vagal nerve schwannoma. Three of 4 patients had spinal intradural, extramedullary nerve sheath tumors. Surgery in all was multistaged and consisted of spinal laminectomies, site-specific explorations, and microsurgical tumor dissection and resection, with intraoperative neurophysiologic monitoring (including somatosensory-evoked and motor-evoked potentials, upper extremity electromyography and intraoperative nerve action potential monitoring, as appropriate). RESULTS: Intraoperatively the schwannomas had cystic and solid features and in all surgical cases the tumors arose from discrete fascicles of sensory nerve roots or sensory peripheral nerve branches. None of the patients experienced neurologic worsening as a result of their resections. Pathologic analysis of specimens from all cases demonstrated schwannoma. CONCLUSIONS: Not all patients with multiple schwannomas of cranial nerve, spinal nerve root, or peripheral nerve origin have NF-1 or NF-2. In schwannomatosis, these lesions are present in the absence of cutaneous stigmata, neurofibromas, vestibular schwannomas, or parenchymal brain tumors. Schwannomas in schwannomatosis can be large, cystic, and multiple. However, the predominant nerve involvement seems to be sensory and discrete fascicular in origin, facilitating microsurgical resection with minimal deficit.     

Malignant schwannoma of the digital nerve in a child. A case report

An extremely rare case of malignant schwannoma (malignant peripheral nerve sheath tumor) arising in the digital nerve in the right ring finger of a child is described. The patient was an 8-year-old boy who did not have neurofibromatosis (von Recklinghausen's disease). He noticed a small tender mass on the tip of his right ring finger in 1991. The lesion was excised twice. However, the tumor recurred soon after each surgery. Histologic examination revealed malignant schwannoma. He eventually underwent disarticulation of the ring finger at the metacarpophalangeal joint in 1995. There was no recurrence or distant metastasis at followup in July 1999. Solitary malignant schwannomas can occur in the small peripheral nerves and in the major nerves.