Dear Editors

We thank Dr Munier and Dr Satgé for their interest in our work on “Aggressive metastasising adenocarcinoma of the retinal pigment epithelium with trisomy 21” [1] and welcome the opportunity to respond to their comments.

We are in agreement with Dr Munier and Dr Satgé that life-threatening ophthalmic tumours must be kept in mind while taking care of patients with Down syndrome. Despite an important progress in life expectancy, solid tumours of the eye and ocular adnexa remain very rare in these patients [2].

In our case report we describe a 37-year-old man with trisomy 21 who presented with a longstanding blind eye with opaque media. Histopathology revealed an aggressive adenocarcinoma of the retinal pigment epithelium (RPE) with marked invasion of the choroid, retina, sclera, orbital and cranial optic nerve and subarachnoid space. The tumour seeded into the lumbar spinal-cord space, and metastatic foci developed in the parietal lobe and cerebellopontine angle [1].

However, the aggressive behaviour of this tumour is clearly atypical for the usual tumour reported as RPE adenocarcinoma in the literature. The fact that aggressive tumor extension and metastasis occur in a middle-aged patient with trisomy 21 is quite remarkable.

Although the most frequent malignant intraocular tumor in blind eyes with opaque media is choroidal melanoma [3], other malignancies with invasive features and metastatic potential, such as adenocarcinoma of the RPE, must be considered in the clinical management, even in patients with Down syndrome.

References
1. Heindl LM, Naumann GOH, Kruse FE, Holbach LM. Aggressive metastasising adenocarcinoma of the retinal pigment epithelium with trisomy 21. Br J Ophthalmol 2008;92:389-91.
2. Satgé D, Lacombe D, Vekemans M, Bonnet A, Réthoré MO, Munier F. A survey of ocular tumors in Down syndrome alone or associated with another genetic affection. Int J Disabil Human Dev 2006;5:311-7.
3. De Gottrau P, Holbach LM, Naumann GOH. Clinicopathological review of 1146 enucleations (1980-90). Br J Ophthalmol 1994;78:260-5.

Dear Editor

A metastizing adenocarcinoma of the retinal pigment epithelium in a 37-year-old man with Down syndrome (DS) has recently been reported in the British Journal of Ophthalmology [1]. In the article the authors underlined an unusual and atypical aggressive behaviour of the tumour which was the first well documented adenocarcinoma of the retinal pigment epithelium with metastases. Although solid tumours are globally less frequent in persons with DS than in the general population [2] this does not seem to apply to ocular neoplasms. Including Heindl's et al report 30 cases of primary or secondary malignant tumours of the eye and orbit have been reported so far, two thirds being retinoblastoma [3]. Unfortunately, but interestingly, some neoplasms in patients with DS may have a rapid progression as observed in a low grade glioma [4]. The reason for this unfavourable course in some patients remains unknown. Nonetheless, as ocular malignant neoplasm could be more frequent in children and adults with DS, and since some of these tumours may have an unexpected aggressive behaviour, we want to attract attention on them to allow a precocious diagnosis and early treatment.

The study on tumors in DS is supported by the Fondation Jérôme Lejeune.

References

1. Heindl LM, Naumann GO, Kruse FE, Holbach LM. Aggressive metastasising adenocarcinoma of the retinal pigment epithelium with trisomy 21. Br J Ophthalmol. 2008;92:389-91

2. Patja K, Pukkala E, Sund R, Iivanainen M, Kaski M. Cancer incidence of persons with Down syndrome in Finland: a population-based study. Int J Cancer. 2006;118:1769-72

3. Satgé D, Lacombe D, Vekemans M, Bonnet A, Réthoré M-O, Munier F. A survey of ocular tumors in Down syndrome alone or associated with another genetic affection. Int J Disabil Human Dev 2006;5:311-7

4. Satgé D, Monteil P, Sasco AJ, Vital A, Ohgaki H, Geneix A, Malet P, Vekemans M, Réthoré MO. Aspects of intracranial and spinal tumors in patients with Down syndrome and report of a rapidly progressing Grade 2 astrocytoma. Cancer. 2001;91:1458-66