A MALIGNANT PERIPHERAL NERVE-SHEATH TUMOUR RESPONDING TO CHEMOTHERAPY

An Analysis of 20 Cases of Radiation-Associated Sarcoma, Including 4 Cases Treated by Carbon Ion Radiotherapy

Introduction Radiation-associated sarcoma (RAS) is one of the most life-threatening complications associated with the treatment of malignant neoplasms. Because all RAS patients have a history of radiotherapy, there have been no effective treatment options when RAS is not completely resected. Methods We retrospectively reviewed 20 RAS patients, including 4 unresectable cases treated by carbon ion radiotherapy (CIRT). Results The primary diseases targeted by radiotherapy included malignant lymphoma (n=4), cervical cancer (n=3), pharyngeal cancer (n=3), breast cancer (n=2), lung cancer (n=1), rectal cancer (n=1), maxillary cancer (n=1), synovial sarcoma (n=1), and benign neoplasms (n=4). The histological diagnoses of RAS included osteosarcoma (n=8), leiomyosarcoma (n=3), undifferentiated pleomorphic sarcoma (n=3), rhabdomyosarcoma (n=1), angiosarcoma (n=1), malignant peripheral nerve sheath tumor (n=1), spindle cell sarcoma NOS (n=1), and sarcoma not further specified (n=2). The median survival time from the diagnosis of RAS was 26 months. Eleven patients underwent surgery. Five of these patients achieved a continuous disease free status or showed no evidence disease. Four patients underwent CIRT. One of these patients with leiomyosarcoma achieved a continuous disease free status, and the other patient with osteosarcoma achieved a partial response. On the other hand, 2 patients experienced Grade 3 toxicities that required surgical treatment. Conclusion RAS originates from various types of diseases that are treated by radiotherapy and shows diverse pathological features. Complete resection achieves a good prognosis. CIRT can be an effective and feasible option for unresectable RAS.

MR imaging features of pancreatic schwannoma: a Chinese case series and a systematic review of 25 cases

BACKGROUND

There is a paucity of existing literature centering on the magnetic resonance (MR) imaging features of pancreatic schwannomas, due to the neoplasm's nonspecific presentation and its rarity. We aimed to identify the characteristic imaging features of pancreatic schwannoma.

METHODS

This retrospective search was conducted for histologically confirmed pancreatic schwannoma in multi-institutional database of pathology. Abdominal magnetic resonance imaging (MRI) was performed before histologic examination and their MR imaging studies were independently reviewed. The search yielded six adults (mean age, 46 years) with a definitive histologic postoperative diagnosis of single pancreatic schwannoma each. Additionally, a comprehensive English and Chinese literature review for pancreatic schwannoma and reported MR-imaging findings since 1961 was also conducted. MR imaging features of those cases in the literature were analyzed, summarized and compared with our case series.

RESULTS

This rare entity appeared to be a well-circumscribed, exophytic, oval or round pancreatic mass with a mean greatest diameter of 3.7 cm. Five schwannomas were located in the pancreatic head-neck and one in the pancreatic tail. On MRI, all cases appeared hypointense on T1-weighted images, inhomogeneous hyperintense on T2-weighted images, and hyperintense on diffusion-weighted images. The mean apparent diffusion coefficient (ADC) values of pancreatic schwannoma were 1.11 ± 0.29 × 10- 3 mm2/s and significantly lower than the surrounding pancreas. The lesion-to-pancreas signal intensity ratio (SIR) at unenhanced T1-weighted images was 0.53 ± 0.07. On dynamic contrast-enhanced MRI, most of the lesions (67%, 4/6) showed homogeneously iso- or hypointense on arterial and portal venous phases, and hyperenhancement on delayed phase compared with the surrounding pancreas. In our analysis of the time intensity curves, all cases exhibited a gradual enhancement pattern.

CONCLUSIONS

A well-circumscribed mass displaying inhomogeneous hyperintensity on T2, marked hypointensity on T1, hyperintensity on DWI, and with early slight enhancement at arterial phase and progressive enhancement at portal venous and delayed phase, may suggest the diagnosis of pancreatic schwannoma.

Successful treatment with doxorubicin and ifosfamide for mediastinal malignant peripheral nerve sheath tumor with loss of H3K27me3 expression

Malignant peripheral nerve sheath tumor (MPNST) in the thorax is an extremely rare disease, and half of all cases of MPNST are associated with neurofibromatosis type I. Sporadic intrathoracic MPNST is difficult to diagnose and treat. Because of the rarity of intrathoracic MPNST, the optimal method of diagnosis and the efficacy of chemotherapy are unknown. Herein, we present a case of inoperable mediastinal MPNST, in which the diagnosis was immunohistochemically made by the loss of H3K27me3 expression in a transbronchial needle biopsy specimen. The patient showed a good response to doxorubicin plus ifosfamide chemotherapy. The present case highlights that MPNST should be included in the differential diagnosis of non‐posterior mediastinum thoracic lesions, and that appropriate diagnosis and treatment for intrathoracic MPNST should be considered in patients with a thoracic mass.

Long-term progress of six cases of malignant peripheral nerve sheath tumors of the mediastinum that underwent surgical treatment: Case report series

INTRODUCTION

Malignant Peripheral Nerve Sheath Tumor is a rare type of soft tissue malignant tumor that occurs in only 5% of cases. It tends to occur in the arms and legs and trunk of the body, with mediastinal occurrence in only a few cases. Among mediastinal tumors, only 18.8% occur primarily in the nerves, and of these, only 10.3% are malignant, with very few reports indicating the long-term progress of patients with MPNST of the mediastinum.

CASE PRESENTATION

We studied six cases of mediastinal primary malignant peripheral nerve sheath tumors in which surgery was carried out at this Center between 1977 and 2000. Four of the cases were men and two were women. The period of observation was between 14 and 277 months and the median follow-up time was 119.5 months. The tumors were contained in a membrane and completely excisable in three cases, with the patient demonstrating long-term survival with no recurrence in each case. The remaining three cases were not completely excisable due to invasion into the aorta. In two cases, the patients were treated post-surgically with chemotherapy; however, in all three cases the patient died as a result of the original condition.

DISCUSSION AND CONCLUSIONS

Nerve sheath tumors localized within the membrane offer good long-term prognosis even if malignant. Furthermore, long-term survival is possible even if the tumor has invaded neighboring organs, provided it can be completely excised. In cases where complete excision is difficult, a multidisciplinary approach including radiotherapy and anti-cancer drug treatment may contribute to improved prognosis but this is a subject that requires further study.

Vanished kidney by pheripheral nerve seath tumor: a rare case report

Malignant peripheral nerve-sheath tumor (MPNST) is a high-grade malignant tumor of ecto-mesenchymal origin comprising approximately 10% of soft-tissue sarcomas. They tend to occur associated with neurofibromatosis or sporadically. Here we report a MPNST at an extremely rare location and behavior causing disappearance of the entire kidney. Patient evaluation included clinical, biochemical and radiological studies before treatment. Histological study revealed the rare diagnosis. Patient was asymptomatic at six-month follow-up after treatment.

Malignant peripheral nerve sheath tumor of non-neurofibromatosis type I metastasized to the cerebrospinal axis

A malignant peripheral nerve sheath tumor (MPNST) is a type of sarcoma that arises from peripheral nerves or cells of the associated nerve sheath. This tumor most commonly metastasizes to the lung and metastases to the spinal cord and brain are very rare. We describe a case of young patient with spinal cord and brain metastases resulting from MPNST. An 18-year-old man presented with a 6-month history of low back pain and radiating pain to his anterior thigh. Magnetic resonance imaging showed a paraspinal mass that extended from the central space of L2 to right psoas muscle through the right L2-3 foraminal space. The patient underwent surgery and the result of the histopathologic study was diagnostic for MPNST. Six months after surgery, follow-up images revealed multiple spinal cord and brain metastases. The patient was managed with chemotherapy, but died several months later. Despite complete surgical excision, the MPNST progressed rapidly and aggressively. Thus, patients with MPNST should be followed carefully to identify local recurrence or metastasis as early as possible.

Pediatric sciatic neuropathy associated with neoplasms

Seven children with sciatic neuropathy associated with an underlying neoplasm are reported. Clinical presentation, electrophysiological data, imaging, pathology, and/or autopsy results are described. Pain and weakness, primarily foot drop, were the most common presenting symptoms. The mechanism of sciatic neuropathy was varied and included: nerve infiltration by the adjacent neoplasm (neuroblastoma, rhabdomyosarcoma, and leukemic or lymphomatous infiltration); an expanding, intrinsic neurogenic tumor (perineurioma); or intraoperative stretch injury (osteosarcoma resection). The prognosis for sciatic nerve recovery was good among children who survived their associated cancer. Three children died from the cancer or complications of treatment. One child with perineurioma remained clinically stable, and two children improved after treatment of their neoplasm.

First-line chemotherapy for malignant peripheral nerve sheath tumor (MPNST) versus other histological soft tissue sarcoma subtypes and as a prognostic factor for MPNST: an EORTC soft tissue and bone sarcoma group study

BACKGROUND

the role of chemotherapy in advanced malignant peripheral nerve sheath tumor (MPNST) is unclear.

PATIENTS AND METHODS

chemotherapy-naive soft tissue sarcomas (STS) patients treated on 12 pooled nonrandomized and randomized European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group trials were retrospectively analyzed. Clinical outcomes, overall survival, progression-free survival (PFS) and response were determined for MPNST and other STS histotypes and compared. Additionally, prognostic factors within the MPNST population were defined. Studied cofactors were demographics, sarcoma history, disease extent and chemotherapy regimen.

RESULTS

after a median follow-up of 4.1 years, 175 MPNST out of 2675 eligible STS patients were analyzed. Outcome was similar for MPNST versus other STS histotypes, with a response rate, median PFS and overall survival of 21% versus 22%, 17 versus 16 weeks and 48 versus 51 weeks, respectively. Performance status was an independent prognostic factor for overall survival. Chemotherapy regimen was an independent prognostic factor for response (P < 0.0001) and PFS (P = 0.009). Compared with standard first-line doxorubicin, the doxorubicin-ifosfamide regimen had the best response, whereas ifosfamide had the worst prognosis.

CONCLUSION

this series indicates the role of chemotherapy in treatment of advanced MPNST. This first comparison showed similar outcomes for MPNST and other STS histotypes. The apparent superiority of the doxorubicin-ifosfamide regimen justifies further investigations of this combination in randomized trials.

Clinicomorphologic features of a series of 10 cases of malignant triton tumors diagnosed over 10 years at a tertiary cancer hospital in Mumbai, India

A rhabdomyoblastic differentiation in a malignant peripheral nerve sheath tumor is unusual and is termed as a malignant triton tumor. A series of 10 such cases with their clinicomorphological features, diagnosed over a 10-year period, is presented. The average age of occurrence was 30 years, with the maximum number of cases in the second decade and with male outnumbering female patients. More cases were seen in the setting of neurofibromatosis. On histology, 80% of the cases were of high grade. Distinct rhabdomyoblastic cells were identified in the areas of malignant peripheral nerve sheath tumor. Immunohistochemistry confirmed the neurogenic differentiation with varying S-100 expression and the rhabdomyoblastic differentiation with desmin and myoglobin positivity in all cases. Surgery with adequate margins constituted the treatment mainstay with adjuvant chemotherapy and/or radiotherapy in individual cases. On follow-up with 7 cases, 3 showed local recurrences, including one that, in addition to another 2 cases, showed lung metastasis. One patient died of the disease. This case along with another high-grade case displayed a diffuse Ki-67 and p53 positivity. Malignant triton tumor is an uncommon tumor associated with an aggressive behavior. Surgery with clear margins is the treatment mainstay. Adjuvant radiotherapy is effective.

Malignant triton tumour of the thigh—A retrospective analysis of nine cases

Malignant triton tumour (MTT) is a very rare soft tissue tumour.

AIM

To report nine patients diagnosed with malignant triton tumour of the thigh between January 1996 and January 2005 to determine the natural history and factors that may affect survival in this aggressive tumour.

METHODS

Due to the association of Neurofibromatosis (NF Type I) with malignant triton tumour, two groups of patients were identified: those with NF type I (Group I cases); and those without (Group II).

RESULTS

Group I patients accounted for four cases and arose predominantly in young males, all tumours being high grade, >10 cm in size and all four patients died within two years of diagnosis. By contrast, the five patients of Group II were older, had smaller size and lower grade tumours and three patients are long-term survivors.

CONCLUSION

Although the number of cases is small, our data supports the views that the natural history of MTT is more aggressive in patients with NF type I. This poor outlook could be attributed to the high frequency of Grade III histology in this disease and the large tumour size.

Diagnosis and treatment options for nerve sheath tumors

The purpose of this review is to discuss the contemporary diagnosis and treatment options for nerve sheath tumors. Common nerve sheath tumors include schwannomas, neurofibromas and malignant nerve sheath tumors. Nerve sheath tumors can be associated with genetic disorders such as neurofibromatosis and schwannomatosis. There is great variation in terms of tumor location, clinical presentation and treatment strategy. Magnetic resonance imaging is the diagnostic study of choice for nerve sheath tumors and surgery has become the mainstay of treatment for most symptomatic lesions. Progress in microsurgical techniques has resulted in significant improvement in surgical outcome, with preservation of neurologic function. Complete resection of benign nerve sheath tumors is the goal of surgical intervention and this results in cure. In contrast, malignant nerve sheath tumors remain a major challenge with poor outcomes overall. Progress in multidisciplinary research may ultimately lead to novel therapeutic strategies.

Spinal Cord Metastasis of a Non-neurofibromatosis Type-1 Malignant Peripheral Nerve Sheath Tumor: An Unusual Manifestation of a Rare Tumor

Malignant peripheral nerve sheath tumors are rare spindle-cell sarcomas derived from Schwann cells or pluripotent cells of the neural crest. They arise from the spinal roots, peripheral nerves, brachial and lumbosacral plexi, cranial nerves and terminal nerve fibers within soft tissue, intestine, lung and bone. These tumors recur either locally, or metastasize distally. Most of these tumors occur in association with neurofibromatosis type 1. Spinal cord metastasis from malignant nerve sheath tumors associated with neurofibromatosis type 1 is very rare. We describe a rare case of near-total spinal cord metastasis in a patient with malignant nerve sheath tumor in the absence of neurofibromatosis, and highlight the microscopic findings and natural history of this disease process.