The Ophthalmology Unit,  Universiti Malaysia Sarawak (UNIMAS), Kuching, Sarawak.
The Ophthalmology Department, Sarawak General Hospital, Kuching, Sarawak, East Malaysia.
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aCase 8a

by Dr.Chua, Dr. Premsenthil, Dr. Premsenthil1 & Dr. Tan Suzet2

1 Oncology Specialist, Kuching General Hospital

2 Head of Radiology, Kuching General Hospital

 

This 12-year-old boy from Indonesia developed an itchy lump in his left upper lid in December 2004. The lump was excised in a local hospital in February, 2005 with out histology. The lump recurred a few months later. The patient consulted a private ophthalmologist in Kuching and the lump was biopsied in August, 2005. Histology revealed pleomorphic rhabdomyosarcoma and the patient was referred to the oncologist in Sarawak General Hospital. Two cycles of uncomplicated chemotherapy were given in August and September, 2005. However, the tumour failed to respond to the treatments and grew rapidly with central necrosis (Figure 1,2). There were no signs of metastasis on physical examination. Ocular examination was difficult but the patient was able to perceive light (Figure 3). The mass was rubbery and appeared to extend into the orbit. A decision was made to debulk the tumour before further chemotherapy and radiotherapy. Urgent CT scan showed the tumour was confined to the upper lid ie. Group III according to Intergroup Rhabdomyosarcoma Study Group Staging Classification (IRSG) (Figure 4).

 

Figure 1.Fungating tumour of the left upper lid (front view).

 

Figure 2. Tumour viewed from the side.

 

Figure 3. The globe could not be opened but the eye could perceive light.

 

Figure 4. Tumour of the upper lid displacing the globe laterally.

No signs of orbital extension or bony involvement.

 

a. What are the different cell types of rhabdomyosarcoma (RMS) and which ophthalmic structures are the most commonly involved ?

Rhabdomyosarcoma can be divided into 3 main histologic types according to histological differentiation:

  • Embryonal RMS (the least differentiated but with most favorable prognosis): it is the most frequently observed in children, accounts for 70% of orbital RMS. It is characterized by bizarrely shaped rhabdomyoblasts with only scanty evidence of cross-striations. Embryonal RMS is further subdivided into:

  • Botryoid tumors which are embryonal tumors that arise under the mucosal surface for example the conjunctiva.

  • Spindle cells variant which rarely affects the eye.

  • Alveolar RMS has the tendency to invade the inferior orbit and generally has poorer prognosis than embryonal RMS. It is so called because the malignant cells are surrounded by circular fibrous septae resembling that in the lung.

 

  • Pleomorphic RMS (as in this patient) contains rhabdomyoblasts that resemble striated muscle fibres. This type usually affects adults and rarely occur in the eye.

In a recent review of 33 pediatric patients, the clinical spectrum of ophthalmic RMS was varied: the tumor was primarily located in the orbit in 76%, conjunctiva in 12%, uveal tract in 9%, eyelid in 3%, and within the globe in 9%.1

RMS is the most common childhood primary orbital malignancy. It accounts for 5% of pediatric orbital masses. The orbital locations of RMS are recognized to have a better prognosis2 than at other sites probably because the disease tends to present early due to the confined space.

 

b. Should exenternation be performed in this patient?

Figure 5. Excised tumour with lid margin.

Ophthalmic RMS do not require exenteration at diagnosis, but rather only a biopsy to establish diagnosis. Biopsy is followed by chemotherapy and radiation therapy, with orbital exenteration reserved for the small number of patients with advanced or recurrent disease. The amount of tissue removed during biopsy is controversial but most ophthalmologists believe only a small biopsy is needed as orbital RMS has a favorable prognosis following radiation and chemotherapy, regardless of the amount of tissue removed. However, some prefer complete, or near complete, surgical removal when that can be achieved without major damage to vital structures like the optic nerve and extraocular muscles.

The use of multimodality therapy (surgery, adjuvant chemotherapy and radiotherapy) has improved the overall prognosis for survival for orbital RMS from the dismal 30% to over 90%.

In this patient, the bulk of the tumour and its failure to respond to chemotherapy necessitated its removal. As RMS is highly malignant supplementary treatment with irradiation and /or chemotherapy is recommended following surgical excision.

 

c. What procedures could be performed during the surgery?

Figure 6. Steps during the excision and reconstruction. The upper lid was excised except

for a small lateral stump. The cornea showed a central area of scarring probably from

pressure keratopathy. Cutler-Beard's technique was used to close the lateral 2/3 of the

upper lid leaving behind a raw area in the medial 1/3 of the upper lid. This area was

closed using glabellar skin flap. The last picture shows the result on the first post-

operative day.

 

As the tumour involved nearly the whole of the upper lid, the excision created a near total loss of the upper lid. Reconstruction of the upper lid was achieved with Cutler-Beard's technique in which the lower lid was used to replace the upper lid defect. Because the excision also involved  a large area of the medial canthal region, the medial 1/3 of the upper lid required additional skin coverage. This was achieved with a glabellar flap (the alternative was a pre- or post-auricular skin graft or from the clavicular region). Another reconstruction to open the eyelid will be performed in about 6 weeks.

 

d. When would you consider further treatment after the surgery?

As RMS is highly malignant, most oncologists will consider orbital radiotherapy for any residual tumour. As the patient just had had extensive surgery, this should be delayed for at least three weeks to allow proper wound healing. The majority of recurrences occurs within the first three years of the original presentation.

Reference:

1. Shields CL, Shields JA, Honavar SC, Demirci H. Clinical spectrum of primary ophthalmic rhabdomyosarcoma. Ophthalmology. 2001;108:2284?292.

2.  Crist WM, Anderson JR, Meza JL, et al. Intergroup rhabdomyosarcoma study IV: results for patients with nonmetastatic disease. J Clin Oncol. 2001;15:3091?102.

3. Shields JA, Shields CL. Rhabdomyosarcoma: review for the ophthalmologist. Surv Ophthalmol. 2003 Jan-Feb;48(1):39-57. Review.

4. Mustarde JC Repair and Reconstruction in the Orbital Region (Hardcover). Churchill Livingstone; 3rd edition (January, 1991).

 

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