title: Malignant Triton Tumor (Malignant Peripheral Nerve Sheath Tumor With Rhabdomyoblastic Differentiation) Occurring in a Vascularized Free Flap Reconstruction Graft.
abstract: Malignant peripheral nerve sheath tumor (MPNST) is a rare form of sarcoma arising from Schwann cells or pluripotent cells of the neural crest. Malignant triton tumor (MTT) is a subtype of MPNST with a component of malignant rhabdomyoblasts in addition to malignant Schwann cells. MPNST and MTT are both aggressive malignancies that most commonly arise from large deep neurofibromas in patients with neurofibromatosis type 1 (NF-1). However, sporadic non-NF-1 cases of MTT have also been reported in the literature. We present a case of a 50-year-old African American male with no stigmata of NF-1 who developed a large mass in a free flap on the right calf. The free flap had been placed by plastic surgery 15 years previously following open right tibial and fibular fractures associated with a large soft tissue defect. Biopsy of the enlarging mass, followed by wide surgical excision, confirmed the pathology to be MTT. Although the development of a high-grade soft tissue sarcoma has been previously reported as a late complication of radiation therapy following free flap reconstructions, we believe this is the first reported case of sarcomatous transformation arising in a vascularized, free muscle transfer.
authors.affiliation: 1 Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Roopa
authors.initials: R
authors.lastname: Ram
authors.affiliation: 2 Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Jerad
authors.initials: J
authors.lastname: Gardner
authors.affiliation: 1 Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Sindhura
authors.initials: S
authors.lastname: Alapati
authors.affiliation: 1 Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Kedar
authors.initials: K
authors.lastname: Jambhekar
authors.affiliation: 1 Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Tarun
authors.initials: T
authors.lastname: Pandey
authors.affiliation: 3 Department of Orthopedics Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Corey
authors.initials: C
authors.lastname: Montgomery
authors.affiliation: 3 Department of Orthopedics Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Nicholas
mesh_terms: D001706:Biopsy; D002454:Cell Differentiation; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D005360:Fibula / Q000293:injuries; D000069076:Fractures, Multiple / Q000150:complications / Q000601:surgery; D058752:Free Tissue Flaps / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D018482:Muscle, Skeletal / Q000473:pathology / Q000637:transplantation; D032448:Myoblasts, Skeletal / Q000473:pathology; D009442:Neurilemmoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D018714:Radiotherapy, Adjuvant; D019651:Plastic Surgery Procedures / Q000009:adverse effects*; D012509:Sarcoma / Q000473:pathology* / Q000628:therapy; D017695:Soft Tissue Injuries / Q000209:etiology / Q000601:surgery; D013978:Tibial Fractures / Q000150:complications / Q000601:surgery; D016378:Tissue Transplantation / Q000009:adverse effects* / Q000379:methods; D014057:Tomography, X-Ray Computed
keywords: free muscle flap; malignant Triton tumor; malignant peripheral nerve sheath tumor; rhabdomyoblasts; sarcoma