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Pediatric Spinal Tumors
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Rajiv R. Iyer, Nir Shimony, Mohammad Hassan A. Noureldine, Eric Bouffet, George I. Jallo
Schwannomas and neurofibromas affect peripheral nerves as they exit the spinal cord and travel towards the neural foramina. Such lesions are also associated with multiple neoplasia syndromes such as NF1 and NF2 (neurofibromas are more common in NF1, whereas schwannomas are more common in NF2). Nerve sheath tumors are more common in the adult population.
Neurofibromatosis Types 1 and 2
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
NF1 (also known as peripheral neurofibromatosis) occurs due to mutations in the tumor suppressor gene NF1. Targeting peripheral nerves and their supporting structures (including neurilemmal cells), NF1 causes multiple café-au-lait spots (or flat, dark patches) on the skin, freckles in the underarms and groin, Lisch nodules in the colored part of the eye (the iris), and neurofibromas on or just under the skin, often near the spinal cord or along nerves elsewhere in the body. Neurofibromas are benign tumors with mixed cell types including Schwann cells, perineural cells, and fibroblasts, along with mast cells, axonal processes, and a collagenous extracellular matrix. However, these tumors have the potential to transform into malignant peripheral nerve sheath tumors, which contribute to early death in affected patients [5]. As a variant of neurofibroma, plexiform neurofibroma arises from muscle nerve fascicles, and may infiltrate into the surrounding structures [6,7].
Schwannoma
Published in Dongyou Liu, Tumors and Cancers, 2017
Austin Huy Nguyen, Adam M. Vaudreuil, Victoria M. Lim, Stephen W. Coons
It is extremely rare for peripheral nerve sheath tumors to become malignant, but when they do occur they carry a significantly worse prognosis. Malignant schwannomas grow rapidly and are more likely to infiltrate tissues, leading to incomplete resection. These aggressive tumors may require chemotherapy or radiation therapy in addition to surgery. Distant metastases may occur and can result in deposits to lung, brain, liver, and bone.
Characteristics, treatment patterns, healthcare resource use, and costs among pediatric patients diagnosed with neurofibromatosis type 1 and plexiform neurofibromas: a retrospective database analysis of a medicaid population
Published in Current Medical Research and Opinion, 2021
Xiaoqin Yang, Kaushal Desai, Neha Agrawal, Kirti Mirchandani, Sagnik Chatterjee, Eric Sarpong, Shuvayu Sen
The major clinical manifestations of NF1 become apparent during childhood and adolescence, and most patients are diagnosed by the age of 87. The diagnostic criteria are well established and include café au lait macules on the skin, Lisch nodules in the eye, dysplasia in the bones, and externally visible or internal neurofibromas8. Approximately 20–50% of NF1 patients exhibit plexiform neurofibromas (PNs)9–12, which are distinguished from other NF1-related tumors by their growth in the nerve sheaths of multiple large nerve bundles and their anatomical invasiveness10,13. They are typically benign but can grow rapidly during childhood and adolescence1,8 and give rise to malignant peripheral nerve sheath tumors14,15.
Selumetinib: the first ever approved drug for neurofibromatosis-1 related inoperable plexiform neurofibroma
Published in Current Medical Research and Opinion, 2021
Sabyasachi Mukhopadhyay, Arpita Maitra, Shouvik Choudhury
Plexiform neurofibroma (PN) arises from multiple nerve fascicles and tends to grow along the length of a nerve. It occurs grossly in 30% cases of NF1 and present from birth usually1. It is the most common cause of morbidity and cosmetic impairment. PN can be both visible from the surface of the body, or may be internal with no evident superficial extension. Growth of PN can occur at any stage of life but mostly in childhood and during hormonal changes. The most alarming feature is the increased risk of transformation into malignant peripheral nerve sheath tumors (MPNST). Treatment remains a surgical challenge, with no established medical approach and surgery is not always possible also due to location, involvement of vital tissue, optimal timing, and incomplete removal etc3.
Triton tumor of the orbit
Published in Orbit, 2020
Atanu Barh, Bipasha Mukherjee, Kirthi Koka, Subramanian Krishnakumar
Peripheral nerve sheath tumors are derived from the pluripotent Schwann cells of the neurilemmal sheath.Many unusual histologic variants within an MPNST have been described, including osteoid, benign striated muscle, cartilage, nevus cells, malignant melanoma, malignant neuroepithelium, liposarcoma, angiosarcoma, and rhabdomyosarcoma (embryonal and pleomorphic).6 The exact pathogenesis of the rhabdomyosarcomatous differentiation within the substance of a peripheral nerve tumor is unclear. MTT was first described by Mason in 1932 as “nerve rhabdomyoma.” In 1973, Woodruff coined the name “malignant triton tumor” inspired by Locatelli’s experiment on triton salamanders capable of growing muscle and bone from nerve tissue.6 Locatelli proposed that endoneurial cells of “neuromas” may differentiate into muscle tissue under the organizing influence of motor nerve fibers. However, limb and muscle regeneration in tritons is not dependent upon motor nerve innervation as even aneurogenic forelimbs of young salamanders may regenerate.6 Later, Masson proposed the more acceptable theory that neoplastic Schwann cells can transform into striated muscle elements which can give rise to rhabdomyosarcomatous differentiation.6