Combined retinal hamartomas leading to the diagnosis of neurofibromatosis type 2

To report two cases of neurofibromatosis type 2 (NF2) initially presenting with isolated bilateral combined hamartomas of the retina and retinal pigment epithelium (RPE).

Retrospective observational case reports.

Two unrelated children presented to ophthalmology with isolated combined hamartomas of the retina and RPE. Patient one presented to ophthalmology at the age of 2 years; by 4 years, he developed what was thought to be a plexiform neurofibroma and, with more than 6 cafe au lait spots, was diagnosed with neurofibromatosis type 1 (NF1). By the age of 5, he had developed bilateral vestibular schwannomas, and was diagnosed with NF2. Subsequent molecular testing revealed a truncating mutation in exon 13 (c.1396C > T; p.R466X) of the NF2 gene. Patient two presented to ophthalmology at the age of 7 months; by age 6 she had developed two subcutaneous masses on her forehead, a mass in her left lower abdomen, and in her gumline. Despite lack of pathological evidence of neurofibroma upon biopsy, molecular testing was initiated at age 6 and revealed a truncating mutation in exon 8 (c.734delA) of the NF2 gene in the blood.

Bilateral combined hamartomas of the retina and retinal pigment epithelium (RPE) in a young child should alert the clinician to the possibility of neurofibromatosis type 2. The recognition of this rare finding as a presenting feature of NF2 can lead to earlier diagnosis, which is vital to appropriate surveillance and possible surgical intervention.