Sir,

We report the case of an 8-year-old girl who presented clinically with a right conjunctival papilloma. As a precaution, because the lesion continued to grow, a biopsy was performed and showed rhabdomyosarcoma. This is a highly unusual presentation of a rare tumour and highlights the need for early biopsy in non-resolving or even mildly atypical lesions.

Case report

An 8-year-old girl presented with a 3-week history of a lesion affecting the plica of the right eye. At onset, she had an URTI. The lesion looked like a papilloma. The size increased and a biopsy was arranged. Figure 1a shows the lesion at this time, 7 weeks after presentation. At surgery, another 2-weeks later, she had developed a smooth, rubbery, mass in the lower lid. An incisional biopsy of the conjunctival papilloma-like lesion was taken. There was a subepithelial, conjunctival, infiltrate of round and spindle-shaped cells with mitotic figures and visible cross-striations (Figure 1c). In areas, rhabdomyoblast-like cells were evident. Cell positivity for desmin (Figure 1d) and myogenin was shown. Histology was consistent with an embryonal rhabdomyosarcoma. The child was referred to the paediatric oncology department. Orbital computed tomography scans showed extension of the tumour beneath the globe. She was treated with nine courses of a combination of ifosfamide, vincristine, and actinomycin.

Figure 1
figure 1

(a) Squamous papilloma-like appearance of rhabdomyosarcoma at the time of biopsy. (b) Histology showing round and spindle-shaped cells with mitoses. (c) Demonstration of cell positivity for desmin. (d) Conjunctival squamous papilloma.

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Comment

Rhabdomyosarcoma, a malignant tumour composed of primitive myogenic cells, although rare, is the most common malignant tumour of the orbit in childhood.1 It can present with sudden and rapidly progressing proptosis, ophthalmoplegia, eyelid erythema, oedema, and ptosis2 or as a localized lesion under the conjunctiva.3 Primary involvement of the conjunctiva is unusual accounting for 12% of cases.4 In this case, the lesion presented as a papilloma. Clinically, papillomas have a delicate vascular core at the centre of each ‘frond’ with a hairpin loop at the frond apex (Figure 1b). Comparison of the lesion in this case with that of the papilloma shows subtle differences such as the lack of a uniform vascular network. This may be of value in alerting the clinician to an alternative diagnosis.

The biopsy showed embryonal rhabdomyosarcoma. These account for 83% of rhabdomyosarcoma cases.5

Current treatment modalities have greatly improved the prognosis for these tumours with the reported 5-year survival rate of embryonal rhabdomyosarcoma up to 94%.6