Treatment of a malignant peripheral nerve sheath tumor and its complications through a multidisciplinary approach

Novel Treatment of a Malignant Peripheral Nerve Sheath Tumor of the Median Nerve

Malignant peripheral nerve sheath tumors are rare, associated with a poor prognosis and uncertainty regarding the appropriate management. We report a novel oncologic and reconstructive treatment of a young patient with a malignant peripheral nerve sheath tumor of the median nerve of the left hand. The patient underwent a wide local excision, an opponensplasty, a nerve reconstruction by nerve allografts followed by brachytherapy treatment. Two years later, the patient remains disease free with preserved function of her hand.

Intrathoracic malignant peripheral nerve sheath tumors: imaging features and implications for management

Background

The aim of the study was to analyze the clinical and imaging characteristics of primary intrathoracic malignant peripheral nerve sheath tumors (MPNSTs).

Patients and methods.

In this institutional review board (IRB)-approved retrospective study, clinical and imaging features of 15 patients (eight men; mean age 50 years [range 18–83)] with pathologically proven malignant peripheral nerve sheath tumors seen from January 1999 to December 2011 were analyzed. Imaging features (CT in 15, MRI in 5 and PET/CT in 4) of primary tumors were evaluated by three radiologists and correlated with clinical management.

Results

Of the 15 tumors, six were located in the mediastinum (two each in anterior, middle and posterior mediastinum), four in chest wall, two were paraspinal, and three in the lung. Four patients had neurofibromatosis-1 (NF1); four tumors had heterologous rhabdomyoblastic differentiation (malignant triton tumor). Masses typically were elongated along the direction of nerves, with mean size of 11 cm. The masses were hypo- or isodense to muscles on CT, isointense on T1-weighted images, hyperintense on T2-weighted images and intensely fluorodeoxyglucose (FDG) avid (mean standardized uptake value [SUV]_max of 10.5 [range 4.4–23.6]). Necrosis and calcification was seen in four tumors each. Finding of invasion of adjacent structures on imaging led to change in management in seven patients; patients with invasion received chemoradiation.

Conclusions

Intrathoracic MPNSTs appear as large elongated masses involving mediastinum, lung or chest wall. Radiological identification of invasion of adjacent structures is crucial and alters therapy, with patients with invasion receiving neoadjuvant or adjuvant chemoradiation.

Primary intraosseous malignant peripheral nerve sheath tumor of spine with a giant paraspinal and retrospinal subcutaneous extension

Background:

According to World Health Organization (WHO) classification of tumors, malignant peripheral nerve sheath tumors (MPNST) encompass the tumors, which were previously termed as malignant schwannoma, neurogenic sarcoma, and neurofibrosarcoma. These are rare tumors constituting only 5% of all malignant soft tissue tumors. As per their name, they arise from the malignant proliferation of cells forming sheath of a nerve root. They cause spinal cord compression, secondary changes in the surrounding bone with variable amount of tumor tissue going into the paraspinal space. However, purely intraosseous origin of the MPNST with no visible connection with a nerve root or dura is rare and few cases have been described in the literature.

Case Description:

We present a primary intraosseous MPNST arising from the body of a thoracic spine with a minimal intraspinal component. However, there was a huge tumor part occupying the paraspinal and retrospinal region. The latter component was so large that it extended to lie just beneath the skin. The intraspinal component was confined to only one level. The giant extraspinal part was spanning multiple corresponding spinal level. We could not find such presentation in the literature.

Conclusion:

Gross total removal (GTR) followed by adjuvant chemo-radiotherapy is the optimal treatment for MPNST of spine. In case of multiple laminectomy or gross spinal instability, spinal instrumentation makes the treatment protocol complete.

Epidural neural fibrolipoma of the thoracic vertebral canal

Neural fibrolipoma is a benign tumor that most frequently infiltrates the median nerve. The authors describe a patient with spinal cord compression syndrome caused by a neural fibrolipoma. The tumor originated in the thoracic nerve at the T6–7 extradural level in the left conjugate foramen and extended into the thoracic cavity. Total removal was achieved by a combined posterior and costotransversectomy approach. Postoperatively, the patient's spinal cord compression syndrome resolved. No tumor recurrence has been observed in medium-term follow-up. This is the second case of an extradural spinal neural fibrolipoma to be reported in the literature.