What is a conjunctival tumor?
Tumours can form on the conjunctiva, as well as on all other tissues of the body. These conjunctival tumours can be benign or malignant. Benign conjunctival tumors are much more common.
Among them are the so-called limbus dermoid and conjunctival papillomas. A tumour does not necessarily mean cancer. In principle, a tumour is just an excessive tissue formation, which is due to mutations in the genetic material.
However, in the case of a benign tumour such as the limbus dermoid, the additional tissue does not cause any damage, as there is no risk of malignant degeneration. A benign conjunctival tumour is restricted to the conjunctiva and does not grow into the adjacent tissue. However, as they are aesthetically striking and do not correspond to the general ideal of beauty, benign conjunctival tumours are often removed.
What tumors are there?
Similar to the rest of the skin, a black skin cancer can also develop on the conjunctiva. At the conjunctiva this is called conjunctival melanoma. A conjunctival melanoma is a malignant conjunctival tumour.
It develops over time from an initially benign melanosis, i.e. an excessive proliferation of pigment cells in the conjunctiva. Due to the large number of pigment cells, the conjunctival melanoma also appears dark brown to black. Due to the dark colouring, the conjunctival melanoma is very well recognizable on the otherwise white conjunctiva as a delimited, black and usually roundish spot, which often grows slightly bulging.
As a conjunctival melanoma is a malignant conjunctival tumour, early removal is recommended and regular follow-up examinations by an ophthalmologist should be performed. If a conjunctival melanoma is not removed, there is a risk that it can grow very quickly into deeper layers of the eye and metastasize. Preferred metastatic routes of conjunctival melanoma are the adjacent lymph nodes in the head and neck area.
At this stage, conjunctival melanoma is very difficult to treat and the complication rate is high. Conjunctival lymphoma is also a malignant tumour of the conjunctiva. It grows as a salmon pink bulge mostly in the lower fold of the lower lid, on the side facing the eye.
As it is externally similar to the harmless conjunctivitis, i.e. an inflammation of the conjunctiva, it sometimes leads to a hasty misdiagnosis. The conjunctival lymphoma should be surgically removed due to its malignant growth. It is not uncommon for conjunctival lymphoma to occur as part of a systemic disease, i.e. one that affects the entire body.
Therefore, when diagnosing conjunctival lymphoma, further malignant processes in the patient should always be looked for. However, if the conjunctival lymphoma is removed in time and there are no further organ involvement, it has a good prognosis. In childhood, conjunctival lymphoma often occurs in the context of a generalized non-Hodgkin lymphoma.
This is a certain type of lymphoma that originates from special cells in the blood, colloquially known as “blood cancer“. The disease can be malignant in different ways depending on the individual. In children from the African region there is an increased incidence of conjunctival lymphomas based on a Burkitt tumour (endemic to Africa).
A conjunctival tumour usually causes comparatively few symptoms in patients. These are primarily dependent on the location, size and type of the conjunctival tumour. Patients often notice a small, darker discolouration of the otherwise white conjunctiva over time, which does not disappear but rather increases in size and intensity.
Sometimes the discoloration is also slightly raised, thus appearing as a kind of small nodule on the otherwise smooth conjunctiva. The vision itself remains completely unaffected by a conjunctival tumor. Some patients describe a foreign body sensation in the eye or a slight swelling, especially when the conjunctival tumour grows in size.
The foreign body sensation or the nodular elevation of the tumour can cause irritation and redness of the conjunctiva, dry eyes and additional conjunctivitis. Regardless of the discolouration caused by the conjunctival tumour, the eye then appears red and increased lacrimation may occur. However, the conjunctival tumour itself does not cause pain.
Vision can at most be somewhat impaired in later stages, when the tumour has already grown so much in size that the eye can no longer be completely closed or the visual axis is no longer aligned centrally. However, these are extreme cases that are no longer encountered in our medically highly developed countries today. As conjunctival tumours are tumours on the outer part of the eye, i.e. the front part visible from the outside, they are usually already clearly visible to the naked eye.
Nevertheless, it is essential to consult an expert ophthalmologist so that he or she can take a closer look at and assess the changes in the conjunctiva using various instruments. Standard is the examination with the slit lamp, which allows a good view of the conjunctiva and the remaining anterior segment of the eye. In addition, the ophthalmologist can artificially dilate the pupil with eye drops to gain a rough overview of what is happening inside the eye and the posterior parts of the eye, such as the retina.
This is important in order to be able to assess the extent and growth of the tumour. Furthermore, the ophthalmologist will want to use imaging techniques to document the findings photographically (which is important to assess the speed of growth) and sectional imaging techniques to examine whether the conjunctival tumour has already spread into the deeper layers. Finally, and ultimately decisive for a final diagnosis, a sample is taken.
This can then be sent to the pathology department, where it will be examined in detail and, using genetic diagnostic methods, will allow a precise differentiation between the different types of conjunctival tumours. If necessary, the specimen collection may also include an attempt to remove the conjunctival tumour in its entirety and send it to the pathology department. Since a conjunctival tumour is a pathological proliferation of tissue at the conjunctiva, surgical removal is ultimately the only possibility to remove this tissue proliferation.
But not every case of conjunctival tumor requires surgery. Benign conjunctival tumours, such as the conjunctival papilloma or the limbus dermoid, are usually not removed. There is no danger of malignant degeneration and their growth is so slow that they do not need to be removed.
However, as they represent a cosmetic problem for some patients and are not compatible with their personal sense of aesthetics, they are nevertheless often removed. Depending on the condition of the conjunctival tumor and the patient, the procedure is performed under local or short-term anesthesia. The conjunctival tumour is then cut out with a fine scalpel and the conjunctiva is glued or sutured if necessary.
The situation is different with malignant conjunctival tumours, such as conjunctival melanoma or conjunctival lymphoma. These are degenerated cancer cells that can potentially grow into the surrounding tissue layers and, in the worst case, spread throughout the entire body. This is why surgery is necessary in any case.
Depending on the type of tumour, chemotherapy or cryotherapy (the freezing of a certain area) can be considered alternatively or additionally, but this must be decided by the ophthalmologist in consultation with the histopathologist. The procedure is similar to the removal of benign tumours, except that a larger area may be removed in order to remove “invisible” tumour cells. Whether benign or malignant, in both cases the tissue removed is subsequently examined and evaluated by a pathologist to determine whether any remaining cells in the eye need to be removed or whether the tumour has been completely excised.
The causes of conjunctival tumours are as diverse as their manifestations and degrees of severity. Like most tumour diseases, conjunctival tumours are caused by a mutation in the genetic material, i.e. in the genes, which are responsible for the abnormal growth of the tissue. These mutations can occur purely by chance, due to small errors that occur during the permanent regeneration and duplication processes in our cells.
Or they can also be caused by external influences. Mutagenic materials and substances primarily include many types of radiation. But it is not only radioactive radiation, such as that found in nuclear power plants, that is harmful to our genetic material.
The everyday radiation in the sun’s rays, the so-called UV A and UV B radiation, can also penetrate through our skin into the genes and set mutation processes in motion there. As a result, it can happen that individual diseased cells degenerate and grow and multiply uninhibitedly. These cells then form the initial tumour cells.
In benign tumors, such as limbus dermoid or conjunctival papilloma, the tumor cells now continue to grow uninhibited and displace the healthy surrounding tissue, but do not penetrate into it or impair its structure and function. The malignant tumour cells are different. They increase in number and size and continue to expand and grow into other cells and destroy them.
This is for example the case with conjunctival lymphomas. Malignant tumours should be treated as soon as possible. Depending on the type and severity of the conjunctival tumour, treatment consists of surgical removal of the tumour and, if necessary, chemotherapeutic follow-up treatment.
In the case of benign tumours, it is often sufficient to control their growth on a regular basis and to initiate appropriate treatment only if the tumour growth is progressing rapidly. – Therapy of the lymphoma
- Implementation of chemotherapy
The prognosis of a conjunctival tumor depends on the type of tumor. The time of diagnosis is also important, as growth may be more advanced depending on the type of tumour.
Benign conjunctival tumours are harmless and only represent a cosmetic impairment of the eye. In principle, they do not have to be removed and could, if the patient does not mind, remain in the eye for the rest of his or her life. Malignant conjunctival tumours, however, especially the conjunctival melanoma (i.e. the black skin cancer of the conjunctiva), must be removed as early as possible and, if necessary, additional irradiation or chemotherapeutic treatment must be administered.
Especially the conjunctival melanoma tends to grow rapidly and form metastases. Once this stage has been reached, treatment is difficult and a complete cure is unfortunately unlikely. In general, a close follow-up by the treating ophthalmologist is of great importance in order to be able to recognize and treat a possible progression of tumor growth or, after surgery, a reappearance of tumor cells in time.
Unfortunately, conjunctival tumours have a strong tendency to recur. This means that the probability of recurrence of a conjunctival tumour is relatively high even after surgical removal. This makes it all the more important to be in contact with the ophthalmologist, to examine oneself regularly and to be attentive.
