Pediatric Sinonasal Rhabdomyosarcoma: Clinical Characteristics and Surgical Role

Abstract

Introduction: Rhabdomyosarcoma is the most common pediatric soft tissue sarcoma. It represents 5-8% of pediatric tumors. Head and neck is considered the most common site of RMS origin (40%). Parameningeal, orbital and non parameningeal RMS approximately represent 50%, 25% and 25% respectively. Histopathological evaluation demonstrates small round cells with high cytological variability which stain positive with desmin, myogenin and MyoD1. The mainstay treatment of RMS depends on chemotherapy and radiation therapy with a limited role of surgery. Method: A retrospective chart review for pediatric sinonasal rhabdomyosarcoma diagnosed and managed at King Fahad Specialist Hospital, Dammam, Saudi Arabia, and a literature review of pediatric sinonasal rhabdomyosarcoma was conducted. Results: A total of four cases were identified for the period (2011-2017), and a thorough review of their medical records and radiological imaging were done. Conclusion: Pediatric sinonasal rhabdomyosarcoma may initially present with symptoms mimicking rhinosinusitis. Biopsy and histological evaluation are the most essential steps to exclude malignancy. Intergroup Rhabdomyosarcoma Studies (IRS) established a staging system based on tumor extension and resectability. The role of surgery in RMS may be limited for obtaining biopsies for diagnosis and for palliative purposes. Popular antineoplastic agents used to treat RMS include vincristine, cyclophosphamide, actinomycin D, and adriamycin. Chemotherapy with alkylating agents has achieved a relapsed free survival 90% for nonparameningeal tumors and 65% for parameningeal tumors.

Nasal Embryonal Rhabdomyosarcoma in the Pediatric Population: Literature Review and Report of Midline Presentation

“…In accordance with the previous literature, the embryonal and alveolar subtypes predominated, accounting for 301 (35.7%) and 367 (43.5%) of cases, respectively. Although embryonal RMS is the most common histological subtype as reported in the literature, particularly in the head and neck and in younger children, [10][11][12][13][14][15] a number of studies have reported that alveolar RMS may be more common in the sinonasal tract specifically, 9,12,16 which is supported by these data.…”

“…As such, the differential diagnosis of a midline nasal mass historically has not included RMS; however, we report the first documented presentation of an RMS as a midline nasal mass in a child. Given RMS’s predilection for early metastasis, 11 – 13 , 16 its omission from the list of differential diagnoses for a midline nasal mass may no longer be appropriate and may have negative clinical implications.…”

“…2,3,[5][6][7] Rhabdomyosarcomas (RMSs) are less common than NDSCs, with an estimated incidence of 4.4-4.5 per 1 million children. 8,9 However, they are the most common soft-tissue sarcomas among the pediatric population, 8,[10][11][12][13][14][15] accounting for 5%-8% of pediatric solid tumors and 2.9% of all pediatric cancers in the United States. 9,11,13 Thirty to forty percent of RMSs affect the head and neck, [8][9][10][11][12][13][14] and 40%-50% of head and neck RMSs affect parameningeal sites such as the nasal cavity, nasopharynx, paranasal sinuses, middle ear, mastoid region, pterygopalatine fossa, and infratemporal fossa.…”

“…9,11,13 Thirty to forty percent of RMSs affect the head and neck, [8][9][10][11][12][13][14] and 40%-50% of head and neck RMSs affect parameningeal sites such as the nasal cavity, nasopharynx, paranasal sinuses, middle ear, mastoid region, pterygopalatine fossa, and infratemporal fossa. 10,11,13 The involvement of parameningeal sites is clinically significant because, like NDSCs, tumors in these areas carry risk of involvement of the skull base and/or intracranial extension, which confers parameningeal RMSs a poorer prognosis. 8,9,12,14,15 Although RMSs are rare, and only a fraction affect parameningeal sites, RMSs are still the most common pediatric malignancies affecting the nose, nasopharynx, and paranasal sinuses.…”

“…[11][12][13]15 There exist botryoid and spindle cell variants of the embryonal subtype, 11,13 and pleomorphic RMS may also be called undifferentiated or anaplastic. [11][12][13] Embryonal RMS is the most common histological subtype, particularly in younger children and in the head and neck. [10][11][12][13][14][15] Alveolar RMS is the second most common histological subtype in children but the most common subtype in adults, often associated with the t(1;13) and t(2;13) PAX-FOX01 translocations, and it may be the most common histological subtype in the sinonasal tract, specifically.…”