Indian Journal of Cancer, Vol. 44, No. 3, July-September, 2007, pp. 104-107
Orbital rhabdomyosarcoma: A case series
Kaliaperumal S, Tiroumal S, Rao VA
Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry - 605 006
Code Number: cn07017
AbstractOrbital rhabdomyosarcoma is the most common orbital malignancy of childhood with the common presentation of rapidly evolving unilateral proptosis. We studied six patients who were diagnosed and treated for rhabdomyosarcoma between January 1999 and June 2004. The age of the patients ranged from 4 to 29 years. Four patients presented with acute onset proptosis associated with signs of inflammation, mimicking orbital cellulitis. One patient presented with lid mass. Another patient presented with a soft, blind eye that was pushed superotemporally by a large inflammed, vascularised mass. Embryonal rhabdomyosarcoma was the commonest histopathological type in our series found in five patients. One patient was completely cured with chemotherapy alone whereas two patients were treated with a combination of chemotherapy and radiotherapy. Three patients in our series required exenteration.
Keywords: Exenteration, proptosis, rhabdomyosarcoma orbital tumor
IntroductionOrbital rhabdomyosarcoma is the most common orbital malignancy of childhood and has been reported as accounting for 4% of all orbital masses in children. ,,, The average age of presentation of this tumour is seven to eight years of age, though the tumor has also been reported in adults and infants.  Rhabdomyosarcoma is well known for its presentation of rapidly evolving unilateral proptosis. , An improvement in the mortality and morbidity of this condition has been associated with the use of recent therapeutic protocols including primary radiotherapy and chemotherapy.
Our study comprised six patients who were diagnosed and treated for rhabdomyosarcoma between January 1999 and June 2004. The age of the patients ranged from 4 to 29 years. Four patients presented with rapid onset proptosis. Of these, one had upward and outward proptosis, two patients had downward and outward proptosis [Figure - 1] and one more presented with axial proptosis. There was an unusual presentation of rapidly progressive upper lid swelling without proptosis in one patient. Another patient presented with atrophic eyeball that was pushed superotemporally by a large inflammed, vascularized mass (4 cm x 3 cm) protruding between the lids.
X-ray findings showed increased bone density in two cases (Cases 3 and 4) and bony erosion in one case (Case 1). CT scan showed an inferomedial extraconal mass in one case [Figure - 2], superonasal extraconal mass in two cases and an intraconal mass in one case. Histopathological examination of the biopsy tissue revealed embryonal rhabdomyosarcoma in five patients and alveolar rhabdomyosarcoma in one patient (Case 5) [Table - 1].
All cases were treated with four to eight cycles of chemotherapy consisting of Vincristine, Cyclophosphamide and Actinomycin D. The cases apart from one (Case 4) received 4000 cGy of radiotherapy over four weeks. Two patients (Case 1 and 6) showed complete tumor regression with chemotherapy and radiotherapy, while another patient (Case 4) completely responded to chemotherapy alone. The remaining three patients (Case 2, 3 and 5) showed resistance to chemotherapy and radiotherapy. They required exenteration as a life-saving measure. In one of these patients (Case 3), exenteration along with medial maxillectomy and ethmoidectomy was performed as the tumor extended into these sinuses [Table - 1].
Rhabdomyosarcoma is usually seen in the first decade of life. Though the presentation of rhabdomyosarcoma in adults is very rare, it has been reported. , In one study by Boparai and Dash, the oldest patient was 19 years whereas in the Chinese-American collaborative study, 4 out of 61 cases were above 20 years of age, the oldest being 56 years of age.  Pleomorphic rhabdomyosarcoma was suggested to occur more commonly in the older age groups.  The oldest in our series was of 29 years of age and had the embryonal type.
The finding of proptosis in children as the most common presenting sign in our patients underlines the importance of orbital rhabdomyosarcoma in the differential diagnosis of such a presentation. Jones et al. , have reported that 100% of the cases in their study had proptosis.  However, Schinter et al. , have documented 71% of cases with proptosis.  Boparai and Dash, in their case series had eleven out of 14 cases presenting with acute onset proptosis with inflammatory signs.  Four out of the six patients in our study presented with acute onset proptosis associated with signs of inflammation such as chemosis, congestion, tenderness and one patient was febrile. Hence rhabdomyosarcoma mimicking as orbital cellulitis is an important consideration to be kept in mind.
It was initially believed that the most common location of the tumor was the superonasal orbit, however, this has not been substantiated by others.  This has in fact been exemplified by the varying locations of the tumor seen in our series. Hence, in general, masses arising in other areas of the orbit in children must not be disregarded. There are also case reports on rhabdomyosarcoma in which the cases have presented as palpable lid nodules and on occasion felt to be a chalazion, cystic lesions or lid tumor of vascular origin. ,,, Such an atypical presentation was also seen in our study (upper lid mass with mechanical ptosis). Awareness about these less common presentations of this fatal malignancy is essential to ensure early detection and initiation of treatment.
X-ray is not of much help in the diagnosis but CT scan gives an idea of the total extent of the lesion. CT scan is also of tremendous value in follow up to detect recurrence.
None were found to have metastatic disease at onset, but in the adult patient, the tumor spread to ethmoid and maxillary sinuses over time even after receiving chemotherapy and radiotherapy. This shows the aggressive nature of these tumors especially when it occurs in the older age group. Recurrence or metastatic spread following rhabdomyosarcoma usually occurs within the first three years after treatment. One of our patients developed recurrent disease at the ninth month. Sutow and co-workers found that six of the 14 cases in their study had recurrence or metastatic spread within the first year after diagnosis.  However, recurrence following treatment of rhabdomyosarcoma as late as six years has also been reported.  Hence the need for long term follow-up of these patients treated for orbital rhabdomyosarcoma.
Four histopathological subtypes of rhabdomyosarcoma have been described: embryonal, alveolar, botryoides and pleomorphic.  It is believed that the embryonal, alveolar and botryoides variants are of mesenchymal origin and that the pleomorphic variant is derived from mature skeletal muscle. The pleomorphic type is the most differentiated type and carries the best prognosis followed by the embryonal and botryoides types. , The alveolar type has been shown to carry the worst prognosis. , Of the three cases that needed exenteration in our study, one case was alveolar rhabdomyosarcoma and two were of embryonal type. Embryonal rhabdomyosarcoma occurs most frequently, accounting for about 71% and 67% cases of orbital rhabdomyosarcoma. , Our study also showed similar frequency with five (83%) cases proving to be embryonal rhabdomyosarcoma.
The practical difficulties need to be considered while obtaining biopsy or doing fine needle aspiration cytology in these patients. The biopsy, in rhabdomyosarcoma is a difficult procedure because the vascularised tumor may result in severe bleeding, hindering the surgical procedure and this may be compounded by the severe chemosis or lid edema associated with this condition.
Earlier orbital rhabdomyosarcoma was treated by orbital exenteration. In 1979, Abraham et al. demonstrated irradiation alone or in combination with chemotherapy to be more effective than exenteration for both control and long-term survival.  Reports of the efficacy of combined radiotherapy and chemotherapy were confirmed by the Intergroup Rhabdomyosarcoma Study, which showed a three-year survival rate of 93% in a total of 127 patients with localized orbital rhabdomyosarcoma.  Radiotherapy and chemotherapy have also been enlisted in treatment of local recurrences and metastatic disease.  In our series of patients, we have noted complete regression of the tumor with chemotherapy and radiotherapy in two cases and with only chemotherapy in one case. However, in the remaining three patients, exenteration had to be performed despite prior treatment with chemotherapy and radiotherapy, as the regression was not complete. The exenteration procedure for such cases of refractory rhabdomyosarcoma was found to be of value in prolonging the survival rate. 
In conclusion, the primary modality of treatment of rhabdomyosarcoma is combined radiotherapy and chemotherapy, which appears to permit effective control and possible cure of this disease. At the time of biopsy, maximum debulking is essential. Exenteration is mutilating and induces the most unfortunate cosmetic appearance postoperatively. However, exenteration may be indicated in cases of incomplete tumor regression or in cases of recurrence after treatment with chemotherapy and radiotherapy. Judgment by the experienced therapist may be valuable in maximizing the gain and minimizing the risk of therapy in individual cases.
Copyright 2007 - Indian Journal of Cancer
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