Sir,

Primary cutaneous melanoma metastatic to the eye is rare.1,2,3,4 Still rarer is melanoma metastasis to the vitreous cavity. A review of the literature showed only seven such cases—Robertson et al5 (two cases), Cole et al6 (one case) and Gunduz et al7 (four eyes of three patients). Diagnosis in one was by primary enucleation for a painful blind eye.6 Two underwent fine needle aspiration biopsy and three had diagnostic vitrectomy. Neither external beam radiotherapy nor chemotherapy was successful in achieving tumour control, with these eyes ultimately being lost as a result of neovascular glaucoma. Non-ocular systemic metastatic disease was usually present at the time of ocular diagnosis. The patients tended to develop cerebral metastases and had a mean survival of 5 months from the time of development of ocular metastases.5,7,8 The present case shows how vitrectomy may have a therapeutic role by providing functional vision and preventing neovascular glaucoma from developing.

Case report

An 87-year-old Caucasian lady was referred with a history of floaters and progressive decrease in vision in the left eye over a 4-week period. She had previously been operated in both eyes for cataract and had good postoperative vision.

She had undergone excision of a cutaneous melanoma from the right cheek 15 months earlier. This was followed by radical neck dissection and radiotherapy. Six months before her ophthalmic presentation, several metastatic lesions were excised from the back of the neck, left arm and anterior abdominal wall.

On examination, the visual acuity was 6/6 in the right eye and hand movements in the affected left eye. Anterior segment examination showed bilateral, quiet pseudophakia. Numerous pigmented clumps were seen on the anterior hyaloid face. The vitreous cavity showed multiple brown cannon-ball opacities. No retinal details were discernible. B scan ultrasonography showed several echogenic points in the vitreous cavity with a flat retina. No choroidal thickening was seen.

The patient underwent a diagnostic and therapeutic pars plana vitrectomy under local anaesthesia. The vitreous cavity showed a dense collection of brown cannon-ball opacities. No choroidal or retinal masses were seen. Histology of the vitreous sample showed small clusters of non-pigmented epithelioid cells with variable amounts of eosinophilic cytoplasm and anisonucleosis (Figure 1). The cells were HMB45 positive, cytokeratin and CD45 negative, consistent with melanoma cells. Postoperatively, the visual acuity improved to 6/24 with correction. Her affected eye retained this level of vision and remained comfortable thereafter with no evidence of recurrence.

Figure 1
figure 1

Haematoxylin & Eosin stain of vitreous sample showing clusters of non-pigmented epithelioid cells with variable eosinophilic cytoplasm and anisonucleosis. The arrow shows one cell with a large, prominent central nucleolus in the nucleus. (× 400).

Full size image

A few days after vitrectomy, the patient developed weakness of her right arm caused by multiple cerebral metastases, which were confirmed by computerised tomography. She was given palliative whole brain radiotherapy consisting of 20 Gy in five fractionated doses and a course of prednisolone 5 mg twice a day. She died of metastatic disease 3 months after vitrectomy.

Discussion

The present case is interesting because the vitrectomy not only achieved a diagnosis but also conserved a comfortable and seeing eye until the patient died a few months later.

Previously reported cases have generally not done so well. Gunduz et al7 treated four eyes of three patients with external beam radiotherapy, three of which continued to develop progressive disease leading to neovascular glaucoma. The fourth eye retained 20/20 vision. Robertson et al5 reported two cases, which were treated with chemotherapy. Both developed neovascular glaucoma with one requiring enucleation for a painful blind eye. Such case reports suggest that neither radiotherapy nor chemotherapy is successful in preventing loss of vision and neovascular glaucoma in these patients. Radiotherapy is unsatisfactory also because the prolonged course of hospital treatment severely disrupts the patient’s last few months of life. Chemotherapy can cause systemic complications, which may be serious.

The vitrectomy we performed was done under local anaesthesia taking only about 30 minutes, and could have been repeated, if necessary, as an out-patient procedure. It was successful in avoiding the development of a painful eye and the need for enucleation. The vitrectomy also improved the vision from hand movements to 6/24. Although our patient had good vision in the fellow eye, the improvement we achieved would have been extremely valuable if the fellow eye had been abnormal.

It would have been interesting to confirm the beneficial effects of vitrectomy in a series of patients. However, vitreous metastases are rare, with only a handful of cases having been reported in the world literature.

In conclusion, if a diagnostic vitrectomy is required in a patient suspected of having vitreous metastases from cutaneous melanoma, it would seem reasonable to perform a total vitrectomy, which may conserve a comfortable seeing eye for the patient’s limited life span without the need for enucleation or radiotherapy.