[Macular combined malformation (hamartoma) of the retina and retinal pigment epithelium]. / Makuläre kombinierte Malformation ("Hamartom") der Netzhaut und des retinalen Pigmentepithels.

ABSTRACT

BACKGROUND: Combined malformations (hamartomas) of the retina and the retinal pigment epithelium are extremely rare. Confusion of these pigmented lesions with choroidal melanomas or other malignancies is possible. MATERIALS AND METHODS: We present the cases of a 7-year-old girl who developed accommodative convergent strabism and the case of an 8-year-old boy with deterioration of visual acuity in the left eye. On examination the anterior segments were normal in both cases. Funduscopically both eyes showed a centrally located large, partly pigmented and slightly prominent tumor, which extended fanlike into the normal-appearing retina. Both lesions were partly obscured by grayish-white, semitranslucent and thickened retina with retinal folds and overlying tortuous vessels. On follow-up examination one lesion seemed to be slightly more pigmented whereas the other lesion remained unchanged. RESULTS AND DISCUSSION: Combined malformations of the retina and the retinal pigment epithelium were originally described as clinical entities (hamartomas) by Gass in 1973. A few additional cases were subsequently published by McLean in 1976, by Laqua and Wessing in 1979 and some other authors. Laqua and Wessing were the first to give a report of a histologic study in one case with a macular lesion that showed two distinguishable components. The outer pigmented portion consisted of hypertrophied retinal pigment epithelium; the inner unpigmented portion consisted of a malformed and thickened retina which, however, showed normal layering. The clinical characteristics are usually diagnostic. Fluorescein angiography is helpful in establishing the diagnosis and ruling out differential diagnoses. CONCLUSION: Although long-term follow-up did not show evidence of growth patients with combined malformation of the retina and retinal pigment epithelium should be followed up regularly.