Intraocular lymphoma
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]
Synonyms and keywords: PIOL
Overview
Intraocular lymphoma (also known as "PIOL") is a rare subtype of primary central nervous system lymphoma. Intraocular lymphoma may affect the eye secondarily from a metastasis from a non-ocular tumor or may arise within the eye primarily. According to the World Health Organization (WHO) classification, intraocular lymphomas are most commonly a diffuse large B-cell immunohistologic subtype of non-Hodgkin's lymphoma. The most common symptoms of intraocular lymphoma is blurred or decreased vision. In the majority of patients, central nervous system involvement, only accounts for 20% of primary central nervous system lymphomas. The median age at diagnosis among patients with intraocular lymphoma is between 50-60 years. The pathogenesis of intraocular lymphoma is characterized by the affection of the sub-retinal pigment epithelium, which is normally involved in the light absorption. On fluorescein angiography, findings may reveal "leopard spot" patterns due to sub-retinal pigment epithelium infiltrates that stain early and progressively or mottling of the sub-retinal pigment epithelium due to hyper- and hypo-fluorescent window defects. The initial therapy for patients with intraocular lymphoma is corticosteroids.[1]
Historical Perspective
- Intraocular lymphoma was first discovered by Samuel Wilks, a British physician, in 1856.
Classification
- According to the World Health Organization (WHO) classification, intraocular lymphomas are most commonly a diffuse large B-cell immunohistologic subtype of non-Hodgkin's lymphoma.
- Primary central nervous system lymphoma may be classified into 5 subtypes:
- Primary cerebral lymphoma
- Primary leptomeningeal lymphoma
- Primary intraocular lymphoma
- Primary spinal lymphoma
- Neurolymphomatosis
Pathophysiology
- Intraocular lymphoma is characterized as a secondary central nervous system lymphoma that mainly affects the optic nerve and the eye.
- The pathogenesis of intraocular lymphoma is characterized by the affection of the sub-retinal pigment epithelium, which is normally involved in the light absorption.
- Genes associated with the development of intraocular lymphoma, include:
- On gross pathology, characteristic findings of intraocular lymphoma, include:
- No remarkable findings
- On microscopic histopathological analysis, characteristic findings of intraocular lymphoma, include:
- Marginal zone (52%)
- Follicular (23%)
- Atypical lymphocytes (gold standard)
Causes
- There are no established causes of intraocular lymphoma.
Differentiating Intraocular Lymphoma from Other Diseases
- Intraocular lymphoma must be differentiated from other diseases that cause chronic loss of vision, or headaches, such as:
- Ocular metastasis (80% of all ocular lesions)
- Choroidal hemangioma
- Vitrous lymphoma
- Retrolental fibroplasia
Epidemiology and Demographics
- The prevalence of intraocular lymphoma remains unknown.
Age
- Intraocular lymphoma is more commonly observed among patients aged 50 to 60 years old.
- Intraocular lymphoma is more commonly observed among middle aged adults.
Gender
- Males are more commonly affected with intraocular lymphoma than females.
Race
- There is no racial predilection for intraocular lymphoma.
Risk Factors
- Common risk factors in the development of intraocular lymphoma, include:
- Toxoplasma gondii infection
Natural History, Complications and Prognosis
- The majority of patients with intraocular lymphoma are symptomatic at the time of diagnosis.
- Early clinical features include symptoms of a non-resolving uveitis, and blurred vision.
- If left untreated, patients with intraocular lymphoma may progress to develop complete vision loss.
- Common complications of intraocular lymphoma, include:
- Prognosis is generally poor, and the median survival rate of patients with intraocular lymphoma is approximately
Diagnosis
Symptoms
- Symptoms of intraocular lymphoma may include the following:
- Burning of the eye
- Redness of the eye
- Blurred vision
- Photophobia or sensitivity to light
- Eye pain
- Floaters (which are dark spots that float in the visual field)
- Headache
- Severe symptoms of intraocular lymphoma, may include:
Physical Examination
- Patients with intraocular lymphoma usually appear pale or malnourished.
- Physical examination may be remarkable for:
- Decreased visual acuity (most common)
- Irregular pupil
- Increased lacrimation
- Eye redness
- Increased intraocular pressure
Laboratory Findings
- There are no specific laboratory findings associated with intraocular lymphoma.
Imaging Findings
- Magnetic resonance image (MRI) is the imaging modality of choice for patients with intraocular lymphoma.
- On MRI, characteristic findings of intraocular lymphoma, include:
- Fat suppressed T2 and post-contrast T1 weighted images, with thin slice thickness and a reduced FOV is ideal, and should include the cavernous sinuses.
- T1: isointense to muscle 8
- T2: hyperintense to muscle, hypointense to fat
- T1 C+ (GAD): enhancement present but variable
Treatment
Medical Therapy
- The initial therapy for intraocular lymphoma is corticosteroids.
- Other medical therapies for intraocular lymphoma, may include:
Surgery
- Surgery is the mainstay of therapy for intraocular lymphoma.
Prevention
- There are no primary preventive measures available for intraocular lymphoma.
- Once diagnosed and successfully treated, patients with intraocular lymphoma are followed-up periodically every 3, 6, or 12 months.
References
- ↑ Hanson JA, Alexandru D and Bota DA: The evaluation and treatment of primary intraocular lymphoma. journal of Cancer Therapeutics and Research 2013, 2:15 http://dx.doi.org/10.7243/2049-7962-2-15