[Retinal Astrocytic Hamartoma in Neurofibromatosis Type 2 - Metaanalysis and a Case Report]

Neurofibromatosis type 2 (NF2) is a genetic condition with an autosomal dominant pattern of inheritance and incomplete penetrance. It is characterized by multiple benign tumors of the central and peripheral nervous system including astrocytomas, ependymomas, meningeomas, and schwannomas, among which bilateral vestibular schwannomas are the most frequent. Among ocular manifestations of NF2, juvenile subcapsular cataract is the most common followed by epiretinal membranes and combined hamartomas of the retina and retinal pigment epithelium.

Multimodal imaging was performed in a female patient and her data were compared to an overview of published cases with retinal hamartoma in NF2.

We report on a case of a 14-year-old girl with genetically confirmed NF2 who presented with bilateral, asymptomatic hyperplasia of glia cells within the ganglion cell and the nerve fibre layer by spectral domain optical coherence tomography (SD-OCT). A metaanalysis of 25 published cases revealed combined hamartomas of the retina and retinal pigment epithelium (CHRRPE) as the most common (16 cases) retinal tumors followed by retinal astrocytic hamartomas (RAH, 7 cases). Retinal hamartomas were most often reported bilaterally and observed prior to the clinical diagnosis of NF2 in 11 of 25 cases. No correlation to sex was observed. Reduced visual acuity, cataracts and epiretinal membranes were the leading ocular manifestations.

There is a large spectrum of ocular-specific findings in NF2. These are seminal, especially at an early age, enabling an early diagnosis and timely therapy of further tumor manifestations. Retinal astrocytic hamartomas may be very discreet and easily missed on routine examination. Fundus infrared imaging is a useful tool allowing to detect even discreet changes rarely seen by ophthalmoscopy in young children. This allows for a more extensive evaluation by SD-OCT.