Introduction
Rhabdomyosarcoma is the most common sarcoma of childhood and the most common neoplasm in childhood after neuroblastoma and nephroblastoma (Carl, 1997; Carol, 2010). It was first described by Webber in 1854 (Abbas, 2005). Rhabdomyosarcomas of the head and neck account for approximately 41% of all paediatric rhabdomyosarcomas,commonly occurring in the orbit, the nasopharynx, and the ear (Hu, 2002; Sautter, 2004). Within the head and neck region, parameningeal rhabdomyosarcoma (PM-RMS) that is tumour arising from the nasal cavity, paranasal sinuses, infratemporal fossa, nasopharynx, or mastoid/middle ear represents 16% of all cases and is associated with early recurrence and poor prognosis (Sautter, 2004; Turner, 2011). Histologically, it is classified into embryonal, alveolar, pleomorphic, and mixed histological subtypes. Embryonal rhabdomyosarcoma is the most common histological variant seen in childhood (Sautter, 2004).

Surgical resection was considered to be the main mode of treatment before the introduction of first Intergroup Rhabdomyosarcoma Study (IRS) in 1972 (Raney, 1983). Second line treatment was radiation therapy, although this resulted in major morbidity and was associated with poor prognosis in majority of the patients(Newton, 1988). However, the management and outcome has greatly improved with the introduction of multimodal treatment (multi-drug chemotherapy in conjunction with radiotherapy and/or surgery) with significant improvement in terms of remission rates in cases of non-metastatic rhabdomyosarcoma in children (Flammant, 1998).We present a case of a 7 years old boy with parameningeal rhabdomyosarcoma who underwent all the three treatment modalities.

1 Case
A 7 year old boy was referred to our clinic with a history of bad breath, nasal obstruction and recurrent epistaxis from the left nostril for 3 months. The epistaxis was frank in nature and stained with mucus. There wasn’t any other bleeding body part. The nasal obstruction started in the left nasal cavity progressively increased to involve the right as well. It was not associated with epiphora or any otologic symptoms. No headache or loss of consciousness was reported. He had neither odynophagia nor dysphagia. On examination he had no lymphadenopathy, had mild left proptosis with normal eye vision and movements, reddish left nasal mass with a smooth surface. Other systems were essentially normal.

Base line Paranasal CT scan showed slightly enhancing soft tissue mass 72×77 mm in the nasal cavity that deviated the nasal septum to the right, extending to the nasopharynx posteriorly and to the maxillary and ethmoidal sinuses as seen in Figure 1~3. In addition there was an 11×16 mm extension of the mass into the orbit.

Figure 1 Tumour in the left nasal cavity extending to the nasopharynx posteriorly and to the left maxillary sinus

Figure 2 Tumour extending to the left orbit

Figure 3 Tumour in the left orbital apex

 
Biopsy was taken and histology showed embryonal rhabdomyosarcoma as shown in Figures 4.

Figure 4 Biopsy was taken and histology showed embryonal rhabdomyosarcoma

 
Under H and E shows poorly differentiated oval dark staining cells in a myxomatous stroma with hyperchromatic nuclei and eosinophilic cytoplasmic characteristics of rhabdomyoblast with little orientation. There are few areas of small interstitial collagen characteristic of Embryonal Rhabdomyosarcoma.

A week later he was taken to theatre where extensive debulking of the tumour was done leaving a small residual of tumour in the orbital apex. He was graded as group III (incomplete resection with gross residual tumour) according to intergroup rhabdomyosarcoma study (IRS) standards. He commenced chemotherapy as per IRS IV protocol, being stage 1 (group III, No, with no Metastasis) he was given vincristine 1.3 mg/day, dactinomycin 360 mg/day and cyclophosphamide 460 mg/day at weekly intervals in a total of 6 cycles. He handled the chemotherapy very well.

Repeated CT scan of the paranasal sinus a month after completion of the chemotherapy showed over 90% tumour reduction, with only residual tumour in the posterior nasal cavity measuring 29×14 mm and no tumour in the left orbit as seen in Figure 5 and Figure 6. He then received a total of 50 Grays of radiotherapy.

Figure 5 Tumour clear maxillary Sinuses after treatment. Some residual tumour in the posterior part of the left nasal cavity

Figure 6 Left orbit clear of tumour

 
2 Discussion
Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood, representing 5% of all childhood cancers (Turner, 2011) .It arises from primitive mesenchymal cells committed to skeletal muscles differentiation and can occur in a variety of organ and tissues, including those without skeletal muscles (Turner, 2011). It has an average age of onset between 4 and 6 years with male preponderance recorded (Mahour, 1967). Our patient is a 7 years old boy.

Presenting symptoms vary from patients and is limited to the site of disease. Pain may be present. If metastatic disease is present, symptoms of bone pain, respiratory difficulty (secondary to lung nodules or to pleural effusion), anemia, thrombocytopenia, and neutropenia may be present.

Survival of children with rhabdomyosarcoma is related to the stage and anatomical location of diseases with bone erosion and malignant cells in cerebral spinal fluid carrying poor prognosis. It was previously suggested that histological subtypes were relevantly unimportant to outcome (Bale, 1986), but recent evidence shows alveolar subtype responds less favourably compared to others (Flammant, 1998; Maurer, 1993).Our patient had embryonal subtype, and has responded very well to both chemotherapy and radiotherapy.

The fundamental goal of therapy for rhabdomyosarcoma (as it is for other solid tumours) is local region control, and prevention or treatment of systemic metastasis. Therefore, all patients are treated systemically with chemotherapy, locally and regionally with radiotherapy, surgery or both. Rarely do occult lymphnodes metastasis occur; hence prophylactic neck dissection is not warranted. It is not always possible to do surgical resection of these tumours, especially where there is intracranial extension or difficult to reach anatomical areas. Like in our patient, extensive surgical resection was done leaving a small tumour in the orbital apex which was later cleared with chemoradiotherapy.

From the original intergroup rhabdomyosarcoma study (IRS), Authors recommended multiagent chemotherapy along with radiotherapy as the mainstay of treatment and that surgery should be performed only if major morbidity can be avoided (Raney, 1983). In the IRS IV protocol, newer agents like etoposides, ifosfamide and melphalan were added to standard treatment of vincristine, actinomycin D, and cyclophosphamide.

The introduction of multimodal treatment (multi-drug chemotherapy in conjunction with radiotherapy and/or surgery) is associated with increase in survival form approximately 25% before formation of multi-institutional trials such as the IRS to 70% with significant improvement in terms of remission rates in cases of non-metastatic rhabdomyosarcoma in children which was evident in our patient.

With regards to the present multimodality treatment regime, patients are categorized according to their risk, which takes into account the location of the tumor, histological and surgical results. Low-risk patients are those who have the best prognosis, whereas intermediate-risk or high-risk patients have an increased risk of having relapses and incurable disease. To separate the features into meaningful categories, patients are assigned to both a surgicopathologic clinical group. All patients with metastatic disease (group IV, stage 4) are considered high risk, except children and adolescents younger than 14 years with embryonal rhabdomyosarcoma (ERMS) (Raney, 1983). Although all patients require chemotherapy, regimens vary depending on the stage and group. In our case, being in group III and stage I, we used a multimodal approach according to IRS IV protocol as pointed out earlier. This gave us a better result as the boy is back in school doing well.

Whereas PM-RMS patients with intra cranial extension may experience CNS failure, they are also at risk for local, regional, and distant failure. Apart from Intra cranial extension, other high-risk features of rhabdomyosarcoma are also applicable to PM-RMS: older age, alveolar histology, and lymph node involvement. Our patient is a young boy and presented with no lymphnode involvement.

3 Conclusion
Advances into the multimodality management have dramatically improved survival in PM-RMS. The timing, volume, and dose of radiation and chemotherapy are critical in the treatment of this disease. As in other malignant tumours of the paediatric population, an optimal balance between cure and toxicity is paramount for both chemotherapy and radiotherapy. The fact that survival improved from approximately 25% before formation of multi-institutional trials such as the IRS to 70% is a remarkable testimony to the effectiveness of multimodal treatment and collaborative multidisciplinary efforts dedicated to the care of children with rhabdomyosarcoma. We recommend thorough examination and investigation including nasopharyngoscopy for patients with recurrent epistaxis.

Authors’ contributions
GB did the initial work-up, did literature review and wrote the initial manuscript. CN and RB did the operation and contributed in the literature review. JN and EK helped in the literature review and writing of the manuscript. DA helped in the preparation of the histopathological slides and special staining.

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