Conjunctival lymphoma is a rare form of cancer that affects the conjunctiva, the clear membrane covering the white part of the eye and the inside of the eyelids. It is a type of ocular malignancy that originates from lymphocytes on the eye’s surface. While lymphomas can occur throughout the body, their presence in the conjunctiva is less common.
What is Conjunctival Lymphoma?
The conjunctiva is a thin, transparent membrane that lines the inner surface of the eyelids and covers the sclera, the white outer layer of the eyeball. This membrane contains specialized lymphoid tissue, forming part of the mucosa-associated lymphoid tissue (MALT) system. When lymphoma, a cancer of the lymphatic system, develops here, it is called conjunctival lymphoma.
Conjunctival lymphoma can be classified as either primary, meaning it originates directly within the eye, or secondary, indicating it has spread from lymphoma elsewhere in the body. The most common subtype is extranodal marginal zone B-cell lymphoma (EMZL) of MALT type. Other B-cell non-Hodgkin lymphoma subtypes, such as diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), can also occur.
Identifying Symptoms and Risk Factors
Symptoms of conjunctival lymphoma are often subtle, potentially delaying diagnosis. A common sign is a painless, salmon-pink, or reddish patch on the conjunctiva, sometimes called a “salmon patch” lesion. This lesion can appear as a smooth surface or a multinodular lesion.
Patients might experience general eye irritation, a sensation of dryness, or feel as though a foreign body is present in the eye. Blurred vision can also occur in some cases. While these symptoms are generally mild and painless, their persistence warrants medical evaluation.
Conjunctival lymphoma is more common in older adults. There may be a slight predominance among females. Some studies suggest a link between MALT lymphomas and chronic inflammatory or autoimmune disorders, as well as certain infections like Chlamydia psittaci.
How Conjunctival Lymphoma is Diagnosed
Diagnosing conjunctival lymphoma begins with a thorough eye examination performed by an ophthalmologist. However, differentiating between benign lymphoid growths and malignant lesions based solely on clinical appearance is not possible. Therefore, a biopsy is a step to confirm the diagnosis.
An incisional or excisional biopsy obtains a tissue sample for pathological examination. This tissue is analyzed under a microscope, often with additional immunohistochemical studies, to identify the specific type of lymphoma. Molecular testing for specific markers can also provide further diagnostic clarity.
Once lymphoma is confirmed, further tests are conducted to determine the extent of the disease and rule out systemic involvement. Imaging studies, such as magnetic resonance imaging (MRI), computed tomography (CT) scans, or positron emission tomography (PET) scans, are used for staging the lymphoma. A bone marrow biopsy might also be performed to assess for any spread beyond the eye.
Treatment Options for Conjunctival Lymphoma
Treatment for conjunctival lymphoma is highly individualized and depends on the type of lymphoma, its stage, and the patient’s overall health. For localized disease, local radiation therapy is a common and effective first-line treatment. This involves directing targeted radiation to the affected area of the eye.
Surgical excision may be considered, particularly for smaller, well-defined lesions. Surgical removal can sometimes be combined with other therapies. Immunotherapy with agents like rituximab can also be employed, sometimes alone or in conjunction with radiation.
When the lymphoma is more widespread, aggressive, or recurs after local treatment, systemic treatments like chemotherapy or a combination of chemotherapy and immunotherapy may be necessary. These treatments aim to target cancer cells throughout the body. The decision for a specific treatment approach is made after careful consideration by a multidisciplinary team of specialists, including ophthalmologists, oncologists, and radiation oncologists.
Prognosis and Long-Term Care
The prognosis for primary conjunctival lymphoma is generally favorable, especially when diagnosed early and treated appropriately. Most cases of primary conjunctival lymphoma follow an indolent, or slow-growing, course. However, even with successful treatment, there is a possibility of recurrence or progression to other parts of the body.
Regular follow-up appointments are therefore important for long-term care. These typically involve routine eye examinations and imaging studies to monitor for any signs of recurrence or systemic spread. A multidisciplinary approach involving ophthalmologists, oncologists, and radiation oncologists helps ensure comprehensive and ongoing care, allowing for timely intervention if the disease reappears.