[Solitary retinal astrocytoma with "acoustic shadowing"]

A polycyclic lesion slightly prominent and yellowish in colour with a mulberry-like surface was incidentally detected in the left eye of a 69-year-old white female. It was located in the nasal horizontal sector of the fundus in a distance of about 5.5 mm from the optic disk. It was surrounded by a bright halo. Retinal arterioles penetrated the lesion superficially and more deeply. The vitreous body was unremarkable. Visual acuity was 0.8 to 1.0 p with a hyperopia of 3.5 dpt. Intraocular pressure was 116 mm Hg. In both eyes partially confluent drusen of the retinal pigment epithelium were present without a serous detachment of the retina. Ultrasound examination revealed an ovally shaped, 1.3-mm prominent solid tumor consisting of highly reflective granular internal echoes with acoustic shadowing behind. X-ray of the skull showed punctate calcifications in the medial orbit. The brain was unremarkable (incl. MRI). In fluorescein angiography the whole tumor was diffusely stained without signs of leakage or subretinal neovascularization. On red-free wide-angle photographs of the retinal nerve fiber layer no localized defects were detected. Neurological and dermatological examination were unremarkable without any hints for tuberous sclerosis or neurofibromatosis. All these findings led to the diagnosis of a solitary retinal astrocytoma. With no therapy performed, the functional and morphological status of the eye remained unchanged one year later.

A retinal astrocytoma is a hamartoma that usually shows no tendency to grow and there is no need for treatment. It can rarely be the reason of a serous retinal detachment or vitreous hemorrhage. Especially solitary astrocytomas have sometimes been reported to show a tendency towards severe intraocular damage. Additional calcifications showing acoustic shadowing in ultrasound examination are important for the differential diagnosis of retinoblastoma.