A 3-year-old Honduran male presented to the emergency department
with a 7 ¥ 10 ¥ 3 cm mass protruding from his right orbit. The
mass, which had been enlarging for 1 year, was friable, with a wet,
yellow, odoriferous exudate and occasional frank bleeding at the
margins. Enucleation of the left eye for retinoblastoma had been
performed on the patient at age 2, followed by chemotherapy.
Invasive retinoblastoma with metastasis.
Retinoblastoma is the most common intraocular malignancy
affecting the pediatric population, with an incidence of 1 in
15,000 to 30,000 live births; approximately 200 new cases are
reported in the United States each year. The diagnosis usually is
made before 2 years of age, with 80% of cases diagnosed under 3
years of age.1,2,3 Both sexes are affected equally.4
Retinoblastoma is a primitive neuroendocrine tumor which
originates in the nuclear layers of the retina and may push upon
the retina, resulting in retinal detachment (endophytic type). It
also may grow as a highly pedunculated mass on a short stalk,
without retinal detachment (exophytic type).2 These tumors grow
rapidly, and necrosis and calcification are common.3
Retinoblastomas are typically identified on computed tomography as
intravitreous soft-tissue masses that enhance following the
administration of intravenous contrast. Calcifications within an
intravitreous soft-tissue mass are virtually pathognomonic of a
retinoblastoma prior to age 3, and are seen in greater than 95% of
cases.6 After age 3, calcifications are slightly less specific, as
they may occasionally be seen in other entities simulating
retinoblastoma such as retinal astrocytoma, toxocariasis, advanced
Coats' disease with retinal necrosis and, rarely, advanced
retinopathy of prematurity.1
Retinoblastoma is responsible for approximately 1% of all cancer
deaths in children under 15 years of age.4 It is hereditary in 40%
of cases, of which three-fourths arise as spontaneous mutations.
When hereditary, retinoblastoma follows an autosomal dominant
pattern, with 80% penetrance. The hereditary form occurs at an
earlier age and is more likely to be bilateral.3 Bilateral disease
occurs in 20 to 40% of all patients with retinoblastoma, and all
patients with bilateral disease have the hereditary form regardless
of family history.3 Associated pinealoma, or the so-called
"trilateral retinoblastoma," occurs in 3% of those patients with
bilateral ocular neoplasms.1,3 A deletion of the 13q14 segment in
the long arm of chromosome 13 has been identified in some patients
with retinoblastoma.5 Associated abnormalities include mental
retardation, extra digits, imperforate anus, and failure to
Initial detection is typically by ophthalmologic diagnosis of
leukokoria (a white pupillary reflex), which is present in 60% of
children with the disease. Strabismus is the second most common
sign, followed by glaucoma, often with heterochromia (different
colored irides).1,2,6 Less common features include a painful red
eye, decreased vision, and orbital inflammation.1,3 In the
developed world, an exophytic orbital mass is a rare presentation
Metastatic disease appears, on average,12 months after initial
diagnosis. Extracranial metastatic disease is rare in the United
States.1,3 Intracranial metastatic lesions have been reported in
virtually all patients dying of retinoblastoma and over 50% have
distant organ metastasis.1,7 The tumor typically invades
intracranially via the optic nerve into the subarachnoid space and
central nervous system. It also can spread hematogeneously to
distant sites following invasion of the optic vein. Prognosis is
related to the stage of the orbital disease rather than the
bilaterality.7 Mortality approaches 100% when there is extraocular
extent of the tumor.2 Children who survive their retinoblastoma are
at an increased risk for osteosarcoma and, less commonly, Ewing's
sarcoma and peripheral neuroepithelioma. Secondary malignant
neoplasms occur almost exclusively in patients with hereditary
Current options in the therapeutic armamentarium include
enucleation, external beam radiation therapy, scleral plaque
brachytherapy, cryotherapy, photocoagulation, and chemotherapy.
Surgical enucleation remains the most commonly used treatment
option.5 However, this is rarely performed for bilateral disease as
it results in immediate blindness. Enucleation in a child under age
3 also results in a small disfigured orbit. Radiation therapy most
often is used to treat the second eye in patients with bilateral
disease.5 Chemotherapy generally is reserved for patients with
extensive extraocular disease.3
1. Provenzale JM, Weber AL, Klintworth GK, McLendon RE:
Radiologic-pathologic correlation: Bilateral retinoblastoma with
coexistent pinealoblastoma. Am J Neuroradiol 16:157-165, 1995.
2. Abramson DH: Retinoblastoma: Diagnosis and Management. CA-A
Cancer J Clin 32(3):130-140, 1982.
3. Cohen MD: Central nervous system tumors. In: Stamathis G
(ed): Imaging of Children with Cancer, pp 305-307. St. Louis, Mosby
Year Book, Inc., 1992.
4. Ralbert DM, Dryja TP: The eye. In: Contran RS, Kumar V,
Robbins SL (eds): Robbin's Pathologic Basis of Disease, ed 4, pp
1462-1646. Philadelphia, WB Saunders 1989.
5. Shields JA, Shields CL: Current Management of Retinoblastoma.
Mayo Clin Proc 69:50-56, 1994.
6. Lindahl S: Computed tomography of the retinoblastoma. Acta
Radiologica Diagn 27:513-518, 1986.
7. MacKay CJ, Abramson DH, Ellsworth RM: Metastatic patterns of
retinoblastoma. Arch Ophthalmol 102:391-396, 1984.
8. Helton KJ, Fletcher BD, Kun LE, et al: Bone tumors other than
osteosarcoma after retinoblastoma. Cancer 71:2847-2853, 1993.
Prepared by James Ronald Hills, MD and Kathleen Dunne Eggli, MD,
Pennsylvania State University College of Medicine, Milton S.
Center, Hershey, PA.