Detection of a congenital cystic eyeball by prenatal ultrasound in a newborn with turner's syndrome

Congenital cystic eyeball was first described in 1939 as a rare ocular malformation caused by partial or complete failure of the optic vesicle to invaginate during fetal development.¹ Only 35 cases have been reported. We present the clinical and histopathological findings in a newborn with Turner's syndrome and a congenital cystic eye.

Case report

A healthy 19‐year‐old woman underwent amniocentesis revealing a 45XO fetal karyotype, consistent with Turner's syndrome. She had good prenatal care, no significant illness or exposures during pregnancy, and family history was noncontributory. At 33 weeks gestation, prenatal ultrasound revealed a severely hypoplastic heart, a duplicated left kidney, and a large cystic orbital mass (fig 1A).

Figure 1 (A) Prenatal fetal ultrasound at 33 weeks' gestation revealed a cystic mass in the right orbit. (B) External photograph of the patient shows the large right cystic orbital mass with partial transillumination. (C) Both cystic and solid (asterisk) components to the mass are appreciated on T2 weighted MRI studies. No globe is discernable on the right side. Parental/guardian informed consent was obtained for publication of this figure.

The infant was born at 38 weeks with characteristic stigmata of Turner's syndrome including webbed neck, broad chest, widely spaced nipples, and pedal lymphedema. The cystic right orbital mass showed partial transillumination (fig 1B). The differential diagnosis included epithelial cyst, orbital cystic teratoma, microphthalmos with cyst, encephalocele, and congenital cystic eye. The left eye was normal.

Ultrasonography and MRI revealed a predominantly cystic but partially solid orbital mass, with no discernable globe (fig 1C). MRI also demonstrated dysplasia of the pons and midbrain. After counseling regarding the infant's poor prognosis, the family withdrew life support and the patient expired.

Histopathology confirmed the diagnosis of cystic eyeball. A cavity lined by mixed fibroglial tissue was observed (fig 2A) with primitive muscle tissue inserting into the cyst wall (fig 2B). A segmental differentiation of sclera, choroid, retinal pigment epithelium, and retina were noted occupying 5% of the posterior wall (fig 2C). Fibroglial tissue with opening to the subarachnoid space was found posteriorly with tissue resembling brain. Primitive optic nerve with surrounding channels was identified (fig 2D). No cornea, iris, ciliary body, or lens was distinctly identified. Immunostaining with neural markers GFAP, NSE, and NF confirmed the glial proliferation with neural elements.

Figure 2 (A) Histopathology shows a cystic cavity which has been ruptured anteriorly (low power). (B) Higher power view with trichrome stain shows the cyst wall to be primarily fibroglial tissues with an area of primitive muscle (arrow) inserting into the cyst wall. (C) Areas of choroidal and retinal pigment epithelium tissue differentiation were identified (shown), and primitive tissue resembling retina was also seen (not shown). (D) Primitive optic nerve (arrow) with surrounding channels (arrowheads) was identified. No lens, ciliary body, iris, or cornea tissues were identified.

Comment

The etiology of congenital cystic eyeball is unknown, and no risk factors have been identified. There is no identifiable globe in this condition, unlike microphthalmos with cyst. Histologically, congenital cystic eye shows a cavity lined by neuroglial tissue. Nonocular abnormalities have been reported in association with congenital cystic eye, including intracranial anomalies as part of an “ectodermopathy”, but these patients had a normal karotype.²

Turner's syndrome results from X chromosome monosomy (45XO), mosaicism, or an abnormality in one X chromosome. Numerous ocular abnormalities have been associated with Turner's syndrome including strabismus, ptosis, hypertelorism, epicanthus, cataracts, glaucoma, anterior segment dysgenesis, retinal neovascularisation, keratoconus, and uveitis.³ One patient with Turner's syndrome has been reported to have ectopic orbital brain tissue, which bears similarity to our case, but that patient had a normal globe.⁴

Prenatal ultrasound has detected ocular abnormalities in utero including microphthalmos, anophthalmos, cataracts, retinoblastoma, and an epithelial orbital cyst.⁵ In our case, prenatal imaging detected the cystic eye.

To our knowledge, congenital cystic eyeball has not been previously reported in a patient with 45XO. Cystic eye should be added to the list of ocular anomalies found in association with Turner's syndrome.