Computed tomography with histopathologic correlation in children with leukokoria

Clinical Case Notes. Retinoblastoma, microphthalmia and the chromosome 13q deletion syndrome

A 10-month-old boy, known to have the 13q deletion syndrome, presented with leukocoria in a microphthalmic right eye. He was found to have bilateral retinoblastoma requiring enucleation of the right eye and laser, cryotherapy and external beam radiation to the left eye. This case demonstrates that retinoblastoma may be present in a microphthalmic eye and that more than one imaging modality should be used in the evaluation of suspected retinoblastoma, as calcification may be absent on the computed tomography scan but present on B-mode ultrasound. Children with a known 13q deletion require immediate and serial ophthalmological examinations.

Medical imaging in pediatric ophthalmology

The use of CT and MR imaging has improved the understanding of many congenital and acquired conditions in pediatric ophthalmology, resulting in more appropriate therapeutic intervention and giving insight into the pathogenesis of these conditions.

Coats' disease and persistent hyperplastic primary vitreous. Role of MR imaging and CT

Coats' disease is an idiopathic disorder in which telangiectatic and aneurysmal retinal vessels leak a lipoproteinaceous exudate, with consequent bullous retinal detachment. It is a diagnostic challenge, and CT and MR imaging provide valuable information to differentiate it from other pathologies, particularly from retinoblastoma. Typical, advanced Coats' disease shows on CT a denser substance posterior to the vitreous, which on MR is hyperintense on all pulse sequences. Contrast administration on both CT and MR might give slight linear enhancement at the boundary between vitreous and exudation. Persistent hyperplastic primary vitreous (PHPV) is a unilateral disorder in a microphthalmic eye, seen in full-term infants. PHPV rarely is bilateral in patients with Norrie's disease, Warburg syndrome, or patients with retinal dysplasia. Persistent fetal vasculature leads to fibrosis, resulting in elongation of the ciliary processes, retinal detachment, and spontaneous cataracts. The CT appearance in the disorder is quite variable; however, MR imaging may be superior in demonstrating the enhancing retrolental mass and the elongated ciliary processes.

Echographic diagnosis of advanced Coats' disease

Standardised echography was utilised to diagnose two cases of advanced Coats' disease. The characteristic acoustic features included extensive, poorly mobile retinal detachment; dense, dispersed subretinal opacities; looping of peripheral retina and absence of solid mass lesion and calcification. As enucleation of two eyes was necessary, it has proved possible to correlate the echographic and histological findings of this disease. The echographic features of other common causes of leukocoria are also discussed.

Magnetic resonance imaging in retinoblastoma and retinocytoma: a case report

Magnetic resonance imaging (MRI) is playing a growing role in the evaluation of ocular and orbital tumors. We report the case of a 26-month-old child presenting an undifferentiated retinoblastoma with a differentiated retinocytoma component in his left eye. After the eye was enucleated, we could correlate the clinicopathologic findings with the MRI scans. Both the undifferentiated retinoblastoma and the differentiated retinocytoma components could be determined on magnetic resonance imaging. Because different levels of metabolic activity within a tumor mass may influence largely T1 and T2 parameters, accurate determination of these values may be useful in determining the differentiation of a retinoblastoma, enabling a better therapeutic approach and assessment of the response to treatment.

Magnetic resonance imaging versus computed tomography of leukocoric eyes and use of in vitro proton magnetic resonance spectroscopy of retinoblastoma

To evaluate the usefulness of magnetic resonance imaging (MRI) in the evaluation of leukocoric eyes, the authors studied 28 patients with either leukocoria or intraocular mass with a 1.5-tesla (T) MRI imager. Retinoblastomas were reliably distinguished from Coats' disease, toxocariasis, and persistent hyperplastic primary vitreous on the basis of MRI findings. Calcification cannot be reliably detected on MRI scans. Lesions elevated less than 4 mm may not be detected reliably by MRI at this time. Computed tomography (CT) can detect calcification with a high degree of accuracy. Retinoblastomas appeared as moderately hyperintense masses on T1- and proton-weighted MRIs. They became hypointense in T2-weighted MRIs. This MRI characteristic is similar to that of uveal melanoma. Intraocular calcification in children especially younger than 3 years of age is highly suggestive of retinoblastoma. In the diagnosis of retinoblastoma, MRI is not as specific as CT because of its lack of sensitivity in detecting calcification. However, MRI, because of its superior contrast resolution, offers more information in the differentiation of pathologic intraocular conditions responsible for leukocoria. The authors also describe their preliminary work of in vitro proton magnetic resonance spectroscopy of eyes with retinoblastoma and an eye with uveal melanoma in an 18-year-old black woman.

Computed tomography of retinoblastoma

Retinoblastoma is the most common primary malignant intraocular tumor in children. The clinical features are leucocoria and/or strabismus. The ophthalmic diagnosis is straight forward in clear eye media with a white gray mass in the fundus. With opaque ocular media, other diagnostic procedures such as CT and ultrasonography are important. In the present study the results of CT examinations of 23 patients with histologically proven retinoblastomas are presented. The mean age of the patients was two years. The characteristic CT finding is a partly calcified intravitreous mass lesion mostly confined within the eyeball. Two cases showed retrobulbar extension and two intracranial tumor extension. No metastasis was found in the brain, liver, spleen, long bones, chest or skull. The radiologic screening procedures for retinoblastoma metastasis are discussed. In patients suspected to have a retinoblastoma, it is recommended to perform CT of the orbits and brain in order to detect the tumor and its possible retrobulbar and intracranial extension.

Computed tomography of the nonrhegmatogenous retinal detachment in the pediatric patient

Nonrhegmatogenous retinal detachments occur in the pediatric population secondary to other ocular disorders. The most important cause to identify is retinoblastoma. Computed tomography has proven to be the most reliable ancillary diagnostic test in this pediatric population. A series of eighty patients, presenting with nonrhegmatogenous retinal detachments, was examined. The role of computed tomography and characteristic clinical findings are discussed.