Anna Silver* has put up with more than her fair share of trouble in her short life. Shortly after she was born, she was diagnosed with persistent fetal vascular syndrome in her right eye, and she underwent a cataract extraction for the condition when she was 3 months old. As for her left eye, Anna has no vision, due to microphthalmos and microcornea.
Then, right about the time of her first birthday, Anna was diagnosed with a retinal detachment in her right eye. Surgery was planned to address this problem, but when Anna’s eye was examined under the operating microscope, the surgeon realized that she had multiple small whitish lesions that looked suspicious for subretinal seeds.
Anna was then referred to us to rule out retinoblastoma in the right eye.
We Get a Look
The ocular exam showed that Anna’s vision in her right eye was wandering gaze with questionable light perception. Testing suggested no light perception in the severely microphthalmic left eye.
The pupil in her right eye was postsurgical and nonreactive (4 millimeters); the pupil in the left eye was 1 mm and not reactive. The corneal diameter on the right was normal at 10 mm, but the left was 6 mm. The pressure was normal, but it was higher in the microphthalmic eye.
On the fundus exam, Anna’s right eye had a clear vitreous but a total retinal detachment, with a tractional band extending from the optic disc to the inferior vitreous base at 6 o’clock (Fig. 1, left). The retina had a peripheral degeneration along with two small, whitish, round retinal opacities suspicious for retinoblastoma (Fig. 2, right). A B-scan was performed; it failed to show any subretinal mass.
Caption: What’s your diagnosis? The right eye showed a clear vitreous and a total retinal detachment (Figure 1, left), as well as some peripheral degeneration (Figure 2, right). Two small opacities also were noted.
Anna’s left eye was examined externally and by B-scan ultrasound and determined to have no evidence of retinal detachments or mass lesions.
At this point, we had two questions: Was this retinoblastoma? Was this ocular history part of a systemic syndrome?
These questions were answered in part during the complete physical exam. Anna was noted to have poorly developed motor skills, and inspection of her head revealed a slight distortion of the skull, manifested by a long, sloping forehead. In addition, she had low-set and slightly malformed ears as well as horizontal palmar creases and tightly flexed hands (Figs. 3 and 4).
Caption: Part of a syndrome: Physical signs of trisomy 13 in our patient included low-set and slightly malformed ears (Figure 3, left) and horizontal palmar creases (Figure 4, right).
An Atypical Case
Anna’s history and physical exam were consistent with trisomy 13 syndrome.
Trisomy 13 is a gross chromosomal disorder involving thousands of genes. As a result, multiple congenital abnormalities are found in this syndrome, but no particular abnormality is consistently present.1 In Anna’s case, chromosomal analysis at birth confirmed that she had three copies of chromosome 13.
Trisomy 13 is found in only 1 in 14,000 live births—and the median survival time of a child with this disorder is just 2.5 days! Eighty-two percent die within the first month of life and only 5 percent survive until 6 months of age. Only one adult has ever been reported in the literature.2 Considering this, our 1-year-old patient was unique.
Is This Retinoblastoma?
Ocular findings in trisomy 13 usually include bilateral microphthalmos. In rare instances, synophthalmos and cyclopia can occur. Persistent fetal vascular syndrome (PFVS; formerly known as persistent hyperplastic primary vitreous) is found in roughly 80 percent of these eyes. Colobomas of the iris and ciliary body are common. Retinal dysplasia is found in 75 percent of eyes. This often is manifested as retinal folds and degeneration of the neural retina3 and it can be associated with PFVS.
Anna is a trisomy 13 patient with an interesting retinal finding that we believe is retinal dysplasia. Exophytic retinoblastoma should have some component of subretinal tumor, and this was not seen on either the clinical fundus exam or the B-scan of the eye.
Histologically, both retinoblastoma and retinal dysplasia can contain rosette or rosette-like structures. Retinal dysplasia rosettes are distinguished from the rosettes of retinoblastoma by their larger size, more numerous cells and frequent oval shape and by the fact that they are identified as sections of a tubular structure.4
Because we cannot obtain a histologic verification of the provisional diagnosis of retinal dysplasia, we will continue to watch Anna with regular follow-up.
* Patient name is fictitious.
1 Keith, C. G. Proc R Soc Med 1968;61(3): 251–253.
2 Jones, Kenneth L. Smith’s Recognizable Patterns of Human Malformation, 5th Edition (Philadelphia: W. B. Saunders, 1996), 18–19.
3 Yanoff, Myron and Ben S. Fine. Ocular Pathology (Philadelphia: W. B. Saunders, 2002), 37–39.
4 Snell, A. Am J Ophthalmol 1965;60(4): 621–627.
Dr. Mango is a fellow in vitreoretinal surgery at the University of California, Los Angeles, and Dr. Abramson is chief of the Service of Ophthalmic Oncology at Memorial Sloan-Kettering Cancer Center in New York.